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* kasan: use %px to print addresses instead of %pTobin C. Harding2017-11-291-4/+4
| | | | | | | | | | Pointers printed with %p are now hashed by default. Kasan needs the actual address. We can use the new printk specifier %px for this purpose. Use %px instead of %p to print addresses. Signed-off-by: Tobin C. Harding <me@tobin.cc>
* slab, slub, slob: add slab_flags_tAlexey Dobriyan2017-11-151-1/+1
| | | | | | | | | | | | | | | | | Add sparse-checked slab_flags_t for struct kmem_cache::flags (SLAB_POISON, etc). SLAB is bloated temporarily by switching to "unsigned long", but only temporarily. Link: http://lkml.kernel.org/r/20171021100225.GA22428@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman2017-11-022-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge branch 'linus' into locking/core, to pick up fixesIngo Molnar2017-08-101-0/+1
|\ | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * kasan: avoid -Wmaybe-uninitialized warningArnd Bergmann2017-08-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | gcc-7 produces this warning: mm/kasan/report.c: In function 'kasan_report': mm/kasan/report.c:351:3: error: 'info.first_bad_addr' may be used uninitialized in this function [-Werror=maybe-uninitialized] print_shadow_for_address(info->first_bad_addr); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ mm/kasan/report.c:360:27: note: 'info.first_bad_addr' was declared here The code seems fine as we only print info.first_bad_addr when there is a shadow, and we always initialize it in that case, but this is relatively hard for gcc to figure out after the latest rework. Adding an intialization to the most likely value together with the other struct members shuts up that warning. Fixes: b235b9808664 ("kasan: unify report headers") Link: https://patchwork.kernel.org/patch/9641417/ Link: http://lkml.kernel.org/r/20170725152739.4176967-1-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Suggested-by: Alexander Potapenko <glider@google.com> Suggested-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | kasan: Allow kasan_check_read/write() to accept pointers to volatilesDmitry Vyukov2017-07-261-2/+2
|/ | | | | | | | | | | | | | | | | | | Currently kasan_check_read/write() accept 'const void*', make them accept 'const volatile void*'. This is required for instrumentation of atomic operations and there is just no reason to not allow that. Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kasan-dev@googlegroups.com Cc: linux-mm@kvack.org Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/33e5ec275c1ee89299245b2ebbccd63709c6021f.1498140838.git.dvyukov@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* kasan: make get_wild_bug_type() staticColin Ian King2017-07-101-1/+1
| | | | | | | | | | | | | | | | | The helper function get_wild_bug_type() does not need to be in global scope, so make it static. Cleans up sparse warning: "symbol 'get_wild_bug_type' was not declared. Should it be static?" Link: http://lkml.kernel.org/r/20170622090049.10658-1-colin.king@canonical.com Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/kasan/kasan.c: rename XXX_is_zero to XXX_is_nonzeroJoonsoo Kim2017-07-101-7/+7
| | | | | | | | | | | | | They return positive value, that is, true, if non-zero value is found. Rename them to reduce confusion. Link: http://lkml.kernel.org/r/20170516012350.GA16015@js1304-desktop Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/kasan: add support for memory hotplugAndrey Ryabinin2017-07-101-5/+35
| | | | | | | | | | | | | | | | | | | | | | | | KASAN doesn't happen work with memory hotplug because hotplugged memory doesn't have any shadow memory. So any access to hotplugged memory would cause a crash on shadow check. Use memory hotplug notifier to allocate and map shadow memory when the hotplugged memory is going online and free shadow after the memory offlined. Link: http://lkml.kernel.org/r/20170601162338.23540-4-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Alexander Potapenko <glider@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/kasan: get rid of speculative shadow checksAndrey Ryabinin2017-07-101-82/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For some unaligned memory accesses we have to check additional byte of the shadow memory. Currently we load that byte speculatively to have only single load + branch on the optimistic fast path. However, this approach has some downsides: - It's unaligned access, so this prevents porting KASAN on architectures which doesn't support unaligned accesses. - We have to map additional shadow page to prevent crash if speculative load happens near the end of the mapped memory. This would significantly complicate upcoming memory hotplug support. I wasn't able to notice any performance degradation with this patch. So these speculative loads is just a pain with no gain, let's remove them. Link: http://lkml.kernel.org/r/20170601162338.23540-1-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/kasan/kasan_init.c: use kasan_zero_pud for p4d tableJoonsoo Kim2017-07-101-0/+12
| | | | | | | | | | | | | | There is missing optimization in zero_p4d_populate() that can save some memory when mapping zero shadow. Implement it like as others. Link: http://lkml.kernel.org/r/1494829255-23946-1-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds2017-05-101-3/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU updates from Ingo Molnar: "The main changes are: - Debloat RCU headers - Parallelize SRCU callback handling (plus overlapping patches) - Improve the performance of Tree SRCU on a CPU-hotplug stress test - Documentation updates - Miscellaneous fixes" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (74 commits) rcu: Open-code the rcu_cblist_n_lazy_cbs() function rcu: Open-code the rcu_cblist_n_cbs() function rcu: Open-code the rcu_cblist_empty() function rcu: Separately compile large rcu_segcblist functions srcu: Debloat the <linux/rcu_segcblist.h> header srcu: Adjust default auto-expediting holdoff srcu: Specify auto-expedite holdoff time srcu: Expedite first synchronize_srcu() when idle srcu: Expedited grace periods with reduced memory contention srcu: Make rcutorture writer stalls print SRCU GP state srcu: Exact tracking of srcu_data structures containing callbacks srcu: Make SRCU be built by default srcu: Fix Kconfig botch when SRCU not selected rcu: Make non-preemptive schedule be Tasks RCU quiescent state srcu: Expedite srcu_schedule_cbs_snp() callback invocation srcu: Parallelize callback handling kvm: Move srcu_struct fields to end of struct kvm rcu: Fix typo in PER_RCU_NODE_PERIOD header comment rcu: Use true/false in assignment to bool rcu: Use bool value directly ...
| * Merge branch 'for-mingo' of ↵Ingo Molnar2017-04-231-3/+3
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu Pull RCU updates from Paul E. McKenney: - Documentation updates. - Miscellaneous fixes. - Parallelize SRCU callback handling (plus overlapping patches). Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * mm: Rename SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCUPaul E. McKenney2017-04-181-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A group of Linux kernel hackers reported chasing a bug that resulted from their assumption that SLAB_DESTROY_BY_RCU provided an existence guarantee, that is, that no block from such a slab would be reallocated during an RCU read-side critical section. Of course, that is not the case. Instead, SLAB_DESTROY_BY_RCU only prevents freeing of an entire slab of blocks. However, there is a phrase for this, namely "type safety". This commit therefore renames SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU in order to avoid future instances of this sort of confusion. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: <linux-mm@kvack.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> [ paulmck: Add comments mentioning the old name, as requested by Eric Dumazet, in order to help people familiar with the old name find the new one. ] Acked-by: David Rientjes <rientjes@google.com>
* | | mm, vmalloc: use __GFP_HIGHMEM implicitlyMichal Hocko2017-05-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __vmalloc* allows users to provide gfp flags for the underlying allocation. This API is quite popular $ git grep "=[[:space:]]__vmalloc\|return[[:space:]]*__vmalloc" | wc -l 77 The only problem is that many people are not aware that they really want to give __GFP_HIGHMEM along with other flags because there is really no reason to consume precious lowmemory on CONFIG_HIGHMEM systems for pages which are mapped to the kernel vmalloc space. About half of users don't use this flag, though. This signals that we make the API unnecessarily too complex. This patch simply uses __GFP_HIGHMEM implicitly when allocating pages to be mapped to the vmalloc space. Current users which add __GFP_HIGHMEM are simplified and drop the flag. Link: http://lkml.kernel.org/r/20170307141020.29107-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Cristopher Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | kasan: separate report parts by empty linesAndrey Konovalov2017-05-031-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Makes the report easier to read. Link: http://lkml.kernel.org/r/20170302134851.101218-10-andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | kasan: improve double-free report formatAndrey Konovalov2017-05-033-18/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Changes double-free report header from BUG: Double free or freeing an invalid pointer Unexpected shadow byte: 0xFB to BUG: KASAN: double-free or invalid-free in kmalloc_oob_left+0xe5/0xef This makes a bug uniquely identifiable by the first report line. To account for removing of the unexpected shadow value, print shadow bytes at the end of the report as in reports for other kinds of bugs. Link: http://lkml.kernel.org/r/20170302134851.101218-9-andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | kasan: print page description after stacksAndrey Konovalov2017-05-031-6/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Moves page description after the stacks since it's less important. Link: http://lkml.kernel.org/r/20170302134851.101218-8-andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | kasan: improve slab object descriptionAndrey Konovalov2017-05-031-11/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Changes slab object description from: Object at ffff880068388540, in cache kmalloc-128 size: 128 to: The buggy address belongs to the object at ffff880068388540 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 123 bytes inside of 128-byte region [ffff880068388540, ffff8800683885c0) Makes it more explanatory and adds information about relative offset of the accessed address to the start of the object. Link: http://lkml.kernel.org/r/20170302134851.101218-7-andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | kasan: change report headerAndrey Konovalov2017-05-031-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change report header format from: BUG: KASAN: use-after-free in unwind_get_return_address+0x28a/0x2c0 at addr ffff880069437950 Read of size 8 by task insmod/3925 to: BUG: KASAN: use-after-free in unwind_get_return_address+0x28a/0x2c0 Read of size 8 at addr ffff880069437950 by task insmod/3925 The exact access address is not usually important, so move it to the second line. This also makes the header look visually balanced. Link: http://lkml.kernel.org/r/20170302134851.101218-6-andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | kasan: simplify address description logicAndrey Konovalov2017-05-031-16/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Simplify logic for describing a memory address. Add addr_to_page() helper function. Makes the code easier to follow. Link: http://lkml.kernel.org/r/20170302134851.101218-5-andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | kasan: change allocation and freeing stack traces headersAndrey Konovalov2017-05-031-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change stack traces headers from: Allocated: PID = 42 to: Allocated by task 42: Makes the report one line shorter and look better. Link: http://lkml.kernel.org/r/20170302134851.101218-4-andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | kasan: unify report headersAndrey Konovalov2017-05-031-13/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Unify KASAN report header format for different kinds of bad memory accesses. Makes the code simpler. Link: http://lkml.kernel.org/r/20170302134851.101218-3-andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | kasan: introduce helper functions for determining bug typeAndrey Konovalov2017-05-031-10/+30
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "kasan: improve error reports", v2. This patchset improves KASAN reports by making them easier to read and a little more detailed. Also improves mm/kasan/report.c readability. Effectively changes a use-after-free report to: ================================================================== BUG: KASAN: use-after-free in kmalloc_uaf+0xaa/0xb6 [test_kasan] Write of size 1 at addr ffff88006aa59da8 by task insmod/3951 CPU: 1 PID: 3951 Comm: insmod Tainted: G B 4.10.0+ #84 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: dump_stack+0x292/0x398 print_address_description+0x73/0x280 kasan_report.part.2+0x207/0x2f0 __asan_report_store1_noabort+0x2c/0x30 kmalloc_uaf+0xaa/0xb6 [test_kasan] kmalloc_tests_init+0x4f/0xa48 [test_kasan] do_one_initcall+0xf3/0x390 do_init_module+0x215/0x5d0 load_module+0x54de/0x82b0 SYSC_init_module+0x3be/0x430 SyS_init_module+0x9/0x10 entry_SYSCALL_64_fastpath+0x1f/0xc2 RIP: 0033:0x7f22cfd0b9da RSP: 002b:00007ffe69118a78 EFLAGS: 00000206 ORIG_RAX: 00000000000000af RAX: ffffffffffffffda RBX: 0000555671242090 RCX: 00007f22cfd0b9da RDX: 00007f22cffcaf88 RSI: 000000000004df7e RDI: 00007f22d0399000 RBP: 00007f22cffcaf88 R08: 0000000000000003 R09: 0000000000000000 R10: 00007f22cfd07d0a R11: 0000000000000206 R12: 0000555671243190 R13: 000000000001fe81 R14: 0000000000000000 R15: 0000000000000004 Allocated by task 3951: save_stack_trace+0x16/0x20 save_stack+0x43/0xd0 kasan_kmalloc+0xad/0xe0 kmem_cache_alloc_trace+0x82/0x270 kmalloc_uaf+0x56/0xb6 [test_kasan] kmalloc_tests_init+0x4f/0xa48 [test_kasan] do_one_initcall+0xf3/0x390 do_init_module+0x215/0x5d0 load_module+0x54de/0x82b0 SYSC_init_module+0x3be/0x430 SyS_init_module+0x9/0x10 entry_SYSCALL_64_fastpath+0x1f/0xc2 Freed by task 3951: save_stack_trace+0x16/0x20 save_stack+0x43/0xd0 kasan_slab_free+0x72/0xc0 kfree+0xe8/0x2b0 kmalloc_uaf+0x85/0xb6 [test_kasan] kmalloc_tests_init+0x4f/0xa48 [test_kasan] do_one_initcall+0xf3/0x390 do_init_module+0x215/0x5d0 load_module+0x54de/0x82b0 SYSC_init_module+0x3be/0x430 SyS_init_module+0x9/0x10 entry_SYSCALL_64_fastpath+0x1f/0xc The buggy address belongs to the object at ffff88006aa59da0 which belongs to the cache kmalloc-16 of size 16 The buggy address is located 8 bytes inside of 16-byte region [ffff88006aa59da0, ffff88006aa59db0) The buggy address belongs to the page: page:ffffea0001aa9640 count:1 mapcount:0 mapping: (null) index:0x0 flags: 0x100000000000100(slab) raw: 0100000000000100 0000000000000000 0000000000000000 0000000180800080 raw: ffffea0001abe380 0000000700000007 ffff88006c401b40 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88006aa59c80: 00 00 fc fc 00 00 fc fc 00 00 fc fc 00 00 fc fc ffff88006aa59d00: 00 00 fc fc 00 00 fc fc 00 00 fc fc 00 00 fc fc >ffff88006aa59d80: fb fb fc fc fb fb fc fc fb fb fc fc fb fb fc fc ^ ffff88006aa59e00: fb fb fc fc fb fb fc fc fb fb fc fc fb fb fc fc ffff88006aa59e80: fb fb fc fc 00 00 fc fc 00 00 fc fc 00 00 fc fc ================================================================== from: ================================================================== BUG: KASAN: use-after-free in kmalloc_uaf+0xaa/0xb6 [test_kasan] at addr ffff88006c4dcb28 Write of size 1 by task insmod/3984 CPU: 1 PID: 3984 Comm: insmod Tainted: G B 4.10.0+ #83 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: dump_stack+0x292/0x398 kasan_object_err+0x1c/0x70 kasan_report.part.1+0x20e/0x4e0 __asan_report_store1_noabort+0x2c/0x30 kmalloc_uaf+0xaa/0xb6 [test_kasan] kmalloc_tests_init+0x4f/0xa48 [test_kasan] do_one_initcall+0xf3/0x390 do_init_module+0x215/0x5d0 load_module+0x54de/0x82b0 SYSC_init_module+0x3be/0x430 SyS_init_module+0x9/0x10 entry_SYSCALL_64_fastpath+0x1f/0xc2 RIP: 0033:0x7feca0f779da RSP: 002b:00007ffdfeae5218 EFLAGS: 00000206 ORIG_RAX: 00000000000000af RAX: ffffffffffffffda RBX: 000055a064c13090 RCX: 00007feca0f779da RDX: 00007feca1236f88 RSI: 000000000004df7e RDI: 00007feca1605000 RBP: 00007feca1236f88 R08: 0000000000000003 R09: 0000000000000000 R10: 00007feca0f73d0a R11: 0000000000000206 R12: 000055a064c14190 R13: 000000000001fe81 R14: 0000000000000000 R15: 0000000000000004 Object at ffff88006c4dcb20, in cache kmalloc-16 size: 16 Allocated: PID = 3984 save_stack_trace+0x16/0x20 save_stack+0x43/0xd0 kasan_kmalloc+0xad/0xe0 kmem_cache_alloc_trace+0x82/0x270 kmalloc_uaf+0x56/0xb6 [test_kasan] kmalloc_tests_init+0x4f/0xa48 [test_kasan] do_one_initcall+0xf3/0x390 do_init_module+0x215/0x5d0 load_module+0x54de/0x82b0 SYSC_init_module+0x3be/0x430 SyS_init_module+0x9/0x10 entry_SYSCALL_64_fastpath+0x1f/0xc2 Freed: PID = 3984 save_stack_trace+0x16/0x20 save_stack+0x43/0xd0 kasan_slab_free+0x73/0xc0 kfree+0xe8/0x2b0 kmalloc_uaf+0x85/0xb6 [test_kasan] kmalloc_tests_init+0x4f/0xa48 [test_kasan] do_one_initcall+0xf3/0x390 do_init_module+0x215/0x5d0 load_module+0x54de/0x82b0 SYSC_init_module+0x3be/0x430 SyS_init_module+0x9/0x10 entry_SYSCALL_64_fastpath+0x1f/0xc2 Memory state around the buggy address: ffff88006c4dca00: fb fb fc fc fb fb fc fc fb fb fc fc fb fb fc fc ffff88006c4dca80: fb fb fc fc fb fb fc fc fb fb fc fc fb fb fc fc >ffff88006c4dcb00: fb fb fc fc fb fb fc fc fb fb fc fc fb fb fc fc ^ ffff88006c4dcb80: fb fb fc fc 00 00 fc fc fb fb fc fc fb fb fc fc ffff88006c4dcc00: fb fb fc fc fb fb fc fc fb fb fc fc fb fb fc fc ================================================================== This patch (of 9): Introduce get_shadow_bug_type() function, which determines bug type based on the shadow value for a particular kernel address. Introduce get_wild_bug_type() function, which determines bug type for addresses which don't have a corresponding shadow value. Link: http://lkml.kernel.org/r/20170302134851.101218-2-andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* / kasan: report only the first error by defaultMark Rutland2017-03-312-5/+36
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | Disable kasan after the first report. There are several reasons for this: - Single bug quite often has multiple invalid memory accesses causing storm in the dmesg. - Write OOB access might corrupt metadata so the next report will print bogus alloc/free stacktraces. - Reports after the first easily could be not bugs by itself but just side effects of the first one. Given that multiple reports usually only do harm, it makes sense to disable kasan after the first one. If user wants to see all the reports, the boot-time parameter kasan_multi_shot must be used. [aryabinin@virtuozzo.com: wrote changelog and doc, added missing include] Link: http://lkml.kernel.org/r/20170323154416.30257-1-aryabinin@virtuozzo.com Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'prep-for-5level'Linus Torvalds2017-03-101-5/+39
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge 5-level page table prep from Kirill Shutemov: "Here's relatively low-risk part of 5-level paging patchset. Merging it now will make x86 5-level paging enabling in v4.12 easier. The first patch is actually x86-specific: detect 5-level paging support. It boils down to single define. The rest of patchset converts Linux MMU abstraction from 4- to 5-level paging. Enabling of new abstraction in most cases requires adding single line of code in arch-specific code. The rest is taken care by asm-generic/. Changes to mm/ code are mostly mechanical: add support for new page table level -- p4d_t -- where we deal with pud_t now. v2: - fix build on microblaze (Michal); - comment for __ARCH_HAS_5LEVEL_HACK in kasan_populate_zero_shadow(); - acks from Michal" * emailed patches from Kirill A Shutemov <kirill.shutemov@linux.intel.com>: mm: introduce __p4d_alloc() mm: convert generic code to 5-level paging asm-generic: introduce <asm-generic/pgtable-nop4d.h> arch, mm: convert all architectures to use 5level-fixup.h asm-generic: introduce __ARCH_USE_5LEVEL_HACK asm-generic: introduce 5level-fixup.h x86/cpufeature: Add 5-level paging detection
| * mm: convert generic code to 5-level pagingKirill A. Shutemov2017-03-091-5/+39
| | | | | | | | | | | | | | | | | | | | | | Convert all non-architecture-specific code to 5-level paging. It's mostly mechanical adding handling one more page table level in places where we deal with pud_t. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | kasan: fix races in quarantine_remove_cache()Dmitry Vyukov2017-03-091-6/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | quarantine_remove_cache() frees all pending objects that belong to the cache, before we destroy the cache itself. However there are currently two possibilities how it can fail to do so. First, another thread can hold some of the objects from the cache in temp list in quarantine_put(). quarantine_put() has a windows of enabled interrupts, and on_each_cpu() in quarantine_remove_cache() can finish right in that window. These objects will be later freed into the destroyed cache. Then, quarantine_reduce() has the same problem. It grabs a batch of objects from the global quarantine, then unlocks quarantine_lock and then frees the batch. quarantine_remove_cache() can finish while some objects from the cache are still in the local to_free list in quarantine_reduce(). Fix the race with quarantine_put() by disabling interrupts for the whole duration of quarantine_put(). In combination with on_each_cpu() in quarantine_remove_cache() it ensures that quarantine_remove_cache() either sees the objects in the per-cpu list or in the global list. Fix the race with quarantine_reduce() by protecting quarantine_reduce() with srcu critical section and then doing synchronize_srcu() at the end of quarantine_remove_cache(). I've done some assessment of how good synchronize_srcu() works in this case. And on a 4 CPU VM I see that it blocks waiting for pending read critical sections in about 2-3% of cases. Which looks good to me. I suspect that these races are the root cause of some GPFs that I episodically hit. Previously I did not have any explanation for them. BUG: unable to handle kernel NULL pointer dereference at 00000000000000c8 IP: qlist_free_all+0x2e/0xc0 mm/kasan/quarantine.c:155 PGD 6aeea067 PUD 60ed7067 PMD 0 Oops: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 0 PID: 13667 Comm: syz-executor2 Not tainted 4.10.0+ #60 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff88005f948040 task.stack: ffff880069818000 RIP: 0010:qlist_free_all+0x2e/0xc0 mm/kasan/quarantine.c:155 RSP: 0018:ffff88006981f298 EFLAGS: 00010246 RAX: ffffea0000ffff00 RBX: 0000000000000000 RCX: ffffea0000ffff1f RDX: 0000000000000000 RSI: ffff88003fffc3e0 RDI: 0000000000000000 RBP: ffff88006981f2c0 R08: ffff88002fed7bd8 R09: 00000001001f000d R10: 00000000001f000d R11: ffff88006981f000 R12: ffff88003fffc3e0 R13: ffff88006981f2d0 R14: ffffffff81877fae R15: 0000000080000000 FS: 00007fb911a2d700(0000) GS:ffff88003ec00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000c8 CR3: 0000000060ed6000 CR4: 00000000000006f0 Call Trace: quarantine_reduce+0x10e/0x120 mm/kasan/quarantine.c:239 kasan_kmalloc+0xca/0xe0 mm/kasan/kasan.c:590 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:544 slab_post_alloc_hook mm/slab.h:456 [inline] slab_alloc_node mm/slub.c:2718 [inline] kmem_cache_alloc_node+0x1d3/0x280 mm/slub.c:2754 __alloc_skb+0x10f/0x770 net/core/skbuff.c:219 alloc_skb include/linux/skbuff.h:932 [inline] _sctp_make_chunk+0x3b/0x260 net/sctp/sm_make_chunk.c:1388 sctp_make_data net/sctp/sm_make_chunk.c:1420 [inline] sctp_make_datafrag_empty+0x208/0x360 net/sctp/sm_make_chunk.c:746 sctp_datamsg_from_user+0x7e8/0x11d0 net/sctp/chunk.c:266 sctp_sendmsg+0x2611/0x3970 net/sctp/socket.c:1962 inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:761 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 SYSC_sendto+0x660/0x810 net/socket.c:1685 SyS_sendto+0x40/0x50 net/socket.c:1653 I am not sure about backporting. The bug is quite hard to trigger, I've seen it few times during our massive continuous testing (however, it could be cause of some other episodic stray crashes as it leads to memory corruption...). If it is triggered, the consequences are very bad -- almost definite bad memory corruption. The fix is non trivial and has chances of introducing new bugs. I am also not sure how actively people use KASAN on older releases. [dvyukov@google.com: - sorted includes[ Link: http://lkml.kernel.org/r/20170309094028.51088-1-dvyukov@google.com Link: http://lkml.kernel.org/r/20170308151532.5070-1-dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Greg Thelen <gthelen@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | kasan: resched in quarantine_remove_cache()Dmitry Vyukov2017-03-091-1/+8
|/ | | | | | | | | | | | | | | | | | | | | | We see reported stalls/lockups in quarantine_remove_cache() on machines with large amounts of RAM. quarantine_remove_cache() needs to scan whole quarantine in order to take out all objects belonging to the cache. Quarantine is currently 1/32-th of RAM, e.g. on a machine with 256GB of memory that will be 8GB. Moreover quarantine scanning is a walk over uncached linked list, which is slow. Add cond_resched() after scanning of each non-empty batch of objects. Batches are specifically kept of reasonable size for quarantine_put(). On a machine with 256GB of RAM we should have ~512 non-empty batches, each with 16MB of objects. Link: http://lkml.kernel.org/r/20170308154239.25440-1-dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Greg Thelen <gthelen@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | | | | | | | | | | <linux/sched/task_stack.h> We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/task_stack.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* kasan, sched/headers: Uninline kasan_enable/disable_current()Ingo Molnar2017-03-021-0/+10
| | | | | | | | | | | | | | | | | | | | | | | <linux/kasan.h> is a low level header that is included early in affected kernel headers. But it includes <linux/sched.h> which complicates the cleanup of sched.h dependencies. But kasan.h has almost no need for sched.h: its only use of scheduler functionality is in two inline functions which are not used very frequently - so uninline kasan_enable_current() and kasan_disable_current(). Also add a <linux/sched.h> dependency to a .c file that depended on kasan.h including it. This paves the way to remove the <linux/sched.h> include from kasan.h. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* kasan: drain quarantine of memcg slab objectsGreg Thelen2017-02-242-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Per memcg slab accounting and kasan have a problem with kmem_cache destruction. - kmem_cache_create() allocates a kmem_cache, which is used for allocations from processes running in root (top) memcg. - Processes running in non root memcg and allocating with either __GFP_ACCOUNT or from a SLAB_ACCOUNT cache use a per memcg kmem_cache. - Kasan catches use-after-free by having kfree() and kmem_cache_free() defer freeing of objects. Objects are placed in a quarantine. - kmem_cache_destroy() destroys root and non root kmem_caches. It takes care to drain the quarantine of objects from the root memcg's kmem_cache, but ignores objects associated with non root memcg. This causes leaks because quarantined per memcg objects refer to per memcg kmem cache being destroyed. To see the problem: 1) create a slab cache with kmem_cache_create(,,,SLAB_ACCOUNT,) 2) from non root memcg, allocate and free a few objects from cache 3) dispose of the cache with kmem_cache_destroy() kmem_cache_destroy() will trigger a "Slab cache still has objects" warning indicating that the per memcg kmem_cache structure was leaked. Fix the leak by draining kasan quarantined objects allocated from non root memcg. Racing memcg deletion is tricky, but handled. kmem_cache_destroy() => shutdown_memcg_caches() => __shutdown_memcg_cache() => shutdown_cache() flushes per memcg quarantined objects, even if that memcg has been rmdir'd and gone through memcg_deactivate_kmem_caches(). This leak only affects destroyed SLAB_ACCOUNT kmem caches when kasan is enabled. So I don't think it's worth patching stable kernels. Link: http://lkml.kernel.org/r/1482257462-36948-1-git-send-email-gthelen@google.com Signed-off-by: Greg Thelen <gthelen@google.com> Reviewed-by: Vladimir Davydov <vdavydov.dev@gmail.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'arm64-upstream' of ↵Linus Torvalds2017-02-221-7/+8
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: - Errata workarounds for Qualcomm's Falkor CPU - Qualcomm L2 Cache PMU driver - Qualcomm SMCCC firmware quirk - Support for DEBUG_VIRTUAL - CPU feature detection for userspace via MRS emulation - Preliminary work for the Statistical Profiling Extension - Misc cleanups and non-critical fixes * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (74 commits) arm64/kprobes: consistently handle MRS/MSR with XZR arm64: cpufeature: correctly handle MRS to XZR arm64: traps: correctly handle MRS/MSR with XZR arm64: ptrace: add XZR-safe regs accessors arm64: include asm/assembler.h in entry-ftrace.S arm64: fix warning about swapper_pg_dir overflow arm64: Work around Falkor erratum 1003 arm64: head.S: Enable EL1 (host) access to SPE when entered at EL2 arm64: arch_timer: document Hisilicon erratum 161010101 arm64: use is_vmalloc_addr arm64: use linux/sizes.h for constants arm64: uaccess: consistently check object sizes perf: add qcom l2 cache perf events driver arm64: remove wrong CONFIG_PROC_SYSCTL ifdef ARM: smccc: Update HVC comment to describe new quirk parameter arm64: do not trace atomic operations ACPI/IORT: Fix the error return code in iort_add_smmu_platform_device() ACPI/IORT: Fix iort_node_get_id() mapping entries indexing arm64: mm: enable CONFIG_HOLES_IN_ZONE for NUMA perf: xgene: Include module.h ...
| * mm/kasan: Switch to using __pa_symbol and lm_aliasLaura Abbott2017-01-111-7/+8
| | | | | | | | | | | | | | | | | | | | | | | | __pa_symbol is the correct API to find the physical address of symbols. Switch to it to allow for debugging APIs to work correctly. Other functions such as p*d_populate may call __pa internally. Ensure that the address passed is in the linear region by calling lm_alias. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
* | kasan: respect /proc/sys/kernel/traceoff_on_warningPeter Zijlstra2017-02-031-0/+3
|/ | | | | | | | | | | | | | | | | After much waiting I finally reproduced a KASAN issue, only to find my trace-buffer empty of useful information because it got spooled out :/ Make kasan_report honour the /proc/sys/kernel/traceoff_on_warning interface. Link: http://lkml.kernel.org/r/20170125164106.3514-1-aryabinin@virtuozzo.com Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'pm-4.10-rc1' of ↵Linus Torvalds2016-12-131-1/+8
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management updates from Rafael Wysocki: "Again, cpufreq gets more changes than the other parts this time (one new driver, one old driver less, a bunch of enhancements of the existing code, new CPU IDs, fixes, cleanups) There also are some changes in cpuidle (idle injection rework, a couple of new CPU IDs, online/offline rework in intel_idle, fixes and cleanups), in the generic power domains framework (mostly related to supporting power domains containing CPUs), and in the Operating Performance Points (OPP) library (mostly related to supporting devices with multiple voltage regulators) In addition to that, the system sleep state selection interface is modified to make it easier for distributions with unchanged user space to support suspend-to-idle as the default system suspend method, some issues are fixed in the PM core, the latency tolerance PM QoS framework is improved a bit, the Intel RAPL power capping driver is cleaned up and there are some fixes and cleanups in the devfreq subsystem Specifics: - New cpufreq driver for Broadcom STB SoCs and a Device Tree binding for it (Markus Mayer) - Support for ARM Integrator/AP and Integrator/CP in the generic DT cpufreq driver and elimination of the old Integrator cpufreq driver (Linus Walleij) - Support for the zx296718, r8a7743 and r8a7745, Socionext UniPhier, and PXA SoCs in the the generic DT cpufreq driver (Baoyou Xie, Geert Uytterhoeven, Masahiro Yamada, Robert Jarzmik) - cpufreq core fix to eliminate races that may lead to using inactive policy objects and related cleanups (Rafael Wysocki) - cpufreq schedutil governor update to make it use SCHED_FIFO kernel threads (instead of regular workqueues) for doing delayed work (to reduce the response latency in some cases) and related cleanups (Viresh Kumar) - New cpufreq sysfs attribute for resetting statistics (Markus Mayer) - cpufreq governors fixes and cleanups (Chen Yu, Stratos Karafotis, Viresh Kumar) - Support for using generic cpufreq governors in the intel_pstate driver (Rafael Wysocki) - Support for per-logical-CPU P-state limits and the EPP/EPB (Energy Performance Preference/Energy Performance Bias) knobs in the intel_pstate driver (Srinivas Pandruvada) - New CPU ID for Knights Mill in intel_pstate (Piotr Luc) - intel_pstate driver modification to use the P-state selection algorithm based on CPU load on platforms with the system profile in the ACPI tables set to "mobile" (Srinivas Pandruvada) - intel_pstate driver cleanups (Arnd Bergmann, Rafael Wysocki, Srinivas Pandruvada) - cpufreq powernv driver updates including fast switching support (for the schedutil governor), fixes and cleanus (Akshay Adiga, Andrew Donnellan, Denis Kirjanov) - acpi-cpufreq driver rework to switch it over to the new CPU offline/online state machine (Sebastian Andrzej Siewior) - Assorted cleanups in cpufreq drivers (Wei Yongjun, Prashanth Prakash) - Idle injection rework (to make it use the regular idle path instead of a home-grown custom one) and related powerclamp thermal driver updates (Peter Zijlstra, Jacob Pan, Petr Mladek, Sebastian Andrzej Siewior) - New CPU IDs for Atom Z34xx and Knights Mill in intel_idle (Andy Shevchenko, Piotr Luc) - intel_idle driver cleanups and switch over to using the new CPU offline/online state machine (Anna-Maria Gleixner, Sebastian Andrzej Siewior) - cpuidle DT driver update to support suspend-to-idle properly (Sudeep Holla) - cpuidle core cleanups and misc updates (Daniel Lezcano, Pan Bian, Rafael Wysocki) - Preliminary support for power domains including CPUs in the generic power domains (genpd) framework and related DT bindings (Lina Iyer) - Assorted fixes and cleanups in the generic power domains (genpd) framework (Colin Ian King, Dan Carpenter, Geert Uytterhoeven) - Preliminary support for devices with multiple voltage regulators and related fixes and cleanups in the Operating Performance Points (OPP) library (Viresh Kumar, Masahiro Yamada, Stephen Boyd) - System sleep state selection interface rework to make it easier to support suspend-to-idle as the default system suspend method (Rafael Wysocki) - PM core fixes and cleanups, mostly related to the interactions between the system suspend and runtime PM frameworks (Ulf Hansson, Sahitya Tummala, Tony Lindgren) - Latency tolerance PM QoS framework imorovements (Andrew Lutomirski) - New Knights Mill CPU ID for the Intel RAPL power capping driver (Piotr Luc) - Intel RAPL power capping driver fixes, cleanups and switch over to using the new CPU offline/online state machine (Jacob Pan, Thomas Gleixner, Sebastian Andrzej Siewior) - Fixes and cleanups in the exynos-ppmu, exynos-nocp, rk3399_dmc, rockchip-dfi devfreq drivers and the devfreq core (Axel Lin, Chanwoo Choi, Javier Martinez Canillas, MyungJoo Ham, Viresh Kumar) - Fix for false-positive KASAN warnings during resume from ACPI S3 (suspend-to-RAM) on x86 (Josh Poimboeuf) - Memory map verification during resume from hibernation on x86 to ensure a consistent address space layout (Chen Yu) - Wakeup sources debugging enhancement (Xing Wei) - rockchip-io AVS driver cleanup (Shawn Lin)" * tag 'pm-4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (127 commits) devfreq: rk3399_dmc: Don't use OPP structures outside of RCU locks devfreq: rk3399_dmc: Remove dangling rcu_read_unlock() devfreq: exynos: Don't use OPP structures outside of RCU locks Documentation: intel_pstate: Document HWP energy/performance hints cpufreq: intel_pstate: Support for energy performance hints with HWP cpufreq: intel_pstate: Add locking around HWP requests PM / sleep: Print active wakeup sources when blocking on wakeup_count reads PM / core: Fix bug in the error handling of async suspend PM / wakeirq: Fix dedicated wakeirq for drivers not using autosuspend PM / Domains: Fix compatible for domain idle state PM / OPP: Don't WARN on multiple calls to dev_pm_opp_set_regulators() PM / OPP: Allow platform specific custom set_opp() callbacks PM / OPP: Separate out _generic_set_opp() PM / OPP: Add infrastructure to manage multiple regulators PM / OPP: Pass struct dev_pm_opp_supply to _set_opp_voltage() PM / OPP: Manage supply's voltage/current in a separate structure PM / OPP: Don't use OPP structure outside of rcu protected section PM / OPP: Reword binding supporting multiple regulators per device PM / OPP: Fix incorrect cpu-supply property in binding cpuidle: Add a kerneldoc comment to cpuidle_use_deepest_state() ..
| *-. Merge branches 'pm-sleep' and 'powercap'Rafael J. Wysocki2016-12-121-1/+8
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * pm-sleep: PM / sleep: Print active wakeup sources when blocking on wakeup_count reads x86/suspend: fix false positive KASAN warning on suspend/resume PM / sleep / ACPI: Use the ACPI_FADT_LOW_POWER_S0 flag PM / sleep: System sleep state selection interface rework PM / hibernate: Verify the consistent of e820 memory map by md5 digest * powercap: powercap / RAPL: Add Knights Mill CPUID powercap/intel_rapl: fix and tidy up error handling powercap/intel_rapl: Track active CPUs internally powercap/intel_rapl: Cleanup duplicated init code powercap/intel rapl: Convert to hotplug state machine powercap/intel_rapl: Propagate error code when registration fails powercap/intel_rapl: Add missing domain data update on hotplug
| | * | x86/suspend: fix false positive KASAN warning on suspend/resumeJosh Poimboeuf2016-12-061-1/+8
| | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Resuming from a suspend operation is showing a KASAN false positive warning: BUG: KASAN: stack-out-of-bounds in unwind_get_return_address+0x11d/0x130 at addr ffff8803867d7878 Read of size 8 by task pm-suspend/7774 page:ffffea000e19f5c0 count:0 mapcount:0 mapping: (null) index:0x0 flags: 0x2ffff0000000000() page dumped because: kasan: bad access detected CPU: 0 PID: 7774 Comm: pm-suspend Tainted: G B 4.9.0-rc7+ #8 Hardware name: Gigabyte Technology Co., Ltd. Z170X-UD5/Z170X-UD5-CF, BIOS F5 03/07/2016 Call Trace: dump_stack+0x63/0x82 kasan_report_error+0x4b4/0x4e0 ? acpi_hw_read_port+0xd0/0x1ea ? kfree_const+0x22/0x30 ? acpi_hw_validate_io_request+0x1a6/0x1a6 __asan_report_load8_noabort+0x61/0x70 ? unwind_get_return_address+0x11d/0x130 unwind_get_return_address+0x11d/0x130 ? unwind_next_frame+0x97/0xf0 __save_stack_trace+0x92/0x100 save_stack_trace+0x1b/0x20 save_stack+0x46/0xd0 ? save_stack_trace+0x1b/0x20 ? save_stack+0x46/0xd0 ? kasan_kmalloc+0xad/0xe0 ? kasan_slab_alloc+0x12/0x20 ? acpi_hw_read+0x2b6/0x3aa ? acpi_hw_validate_register+0x20b/0x20b ? acpi_hw_write_port+0x72/0xc7 ? acpi_hw_write+0x11f/0x15f ? acpi_hw_read_multiple+0x19f/0x19f ? memcpy+0x45/0x50 ? acpi_hw_write_port+0x72/0xc7 ? acpi_hw_write+0x11f/0x15f ? acpi_hw_read_multiple+0x19f/0x19f ? kasan_unpoison_shadow+0x36/0x50 kasan_kmalloc+0xad/0xe0 kasan_slab_alloc+0x12/0x20 kmem_cache_alloc_trace+0xbc/0x1e0 ? acpi_get_sleep_type_data+0x9a/0x578 acpi_get_sleep_type_data+0x9a/0x578 acpi_hw_legacy_wake_prep+0x88/0x22c ? acpi_hw_legacy_sleep+0x3c7/0x3c7 ? acpi_write_bit_register+0x28d/0x2d3 ? acpi_read_bit_register+0x19b/0x19b acpi_hw_sleep_dispatch+0xb5/0xba acpi_leave_sleep_state_prep+0x17/0x19 acpi_suspend_enter+0x154/0x1e0 ? trace_suspend_resume+0xe8/0xe8 suspend_devices_and_enter+0xb09/0xdb0 ? printk+0xa8/0xd8 ? arch_suspend_enable_irqs+0x20/0x20 ? try_to_freeze_tasks+0x295/0x600 pm_suspend+0x6c9/0x780 ? finish_wait+0x1f0/0x1f0 ? suspend_devices_and_enter+0xdb0/0xdb0 state_store+0xa2/0x120 ? kobj_attr_show+0x60/0x60 kobj_attr_store+0x36/0x70 sysfs_kf_write+0x131/0x200 kernfs_fop_write+0x295/0x3f0 __vfs_write+0xef/0x760 ? handle_mm_fault+0x1346/0x35e0 ? do_iter_readv_writev+0x660/0x660 ? __pmd_alloc+0x310/0x310 ? do_lock_file_wait+0x1e0/0x1e0 ? apparmor_file_permission+0x18/0x20 ? security_file_permission+0x73/0x1c0 ? rw_verify_area+0xbd/0x2b0 vfs_write+0x149/0x4a0 SyS_write+0xd9/0x1c0 ? SyS_read+0x1c0/0x1c0 entry_SYSCALL_64_fastpath+0x1e/0xad Memory state around the buggy address: ffff8803867d7700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8803867d7780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8803867d7800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f4 ^ ffff8803867d7880: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 ffff8803867d7900: 00 00 00 f1 f1 f1 f1 04 f4 f4 f4 f3 f3 f3 f3 00 KASAN instrumentation poisons the stack when entering a function and unpoisons it when exiting the function. However, in the suspend path, some functions never return, so their stack never gets unpoisoned, resulting in stale KASAN shadow data which can cause later false positive warnings like the one above. Reported-by: Scott Bauer <scott.bauer@intel.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | | kasan: eliminate long stalls during quarantine reductionDmitry Vyukov2016-12-121-46/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently we dedicate 1/32 of RAM for quarantine and then reduce it by 1/4 of total quarantine size. This can be a significant amount of memory. For example, with 4GB of RAM total quarantine size is 128MB and it is reduced by 32MB at a time. With 128GB of RAM total quarantine size is 4GB and it is reduced by 1GB. This leads to several problems: - freeing 1GB can take tens of seconds, causes rcu stall warnings and just introduces unexpected long delays at random places - if kmalloc() is called under a mutex, other threads stall on that mutex while a thread reduces quarantine - threads wait on quarantine_lock while one thread grabs a large batch of objects to evict - we walk the uncached list of object to free twice which makes all of the above worse - when a thread frees objects, they are already not accounted against global_quarantine.bytes; as the result we can have quarantine_size bytes in quarantine + unbounded amount of memory in large batches in threads that are in process of freeing Reduce size of quarantine in smaller batches to reduce the delays. The only reason to reduce it in batches is amortization of overheads, the new batch size of 1MB should be well enough to amortize spinlock lock/unlock and few function calls. Plus organize quarantine as a FIFO array of batches. This allows to not walk the list in quarantine_reduce() under quarantine_lock, which in turn reduces contention and is just faster. This improves performance of heavy load (syzkaller fuzzing) by ~20% with 4 CPUs and 32GB of RAM. Also this eliminates frequent (every 5 sec) drops of CPU consumption from ~400% to ~100% (one thread reduces quarantine while others are waiting on a mutex). Some reference numbers: 1. Machine with 4 CPUs and 4GB of memory. Quarantine size 128MB. Currently we free 32MB at at time. With new code we free 1MB at a time (1024 batches, ~128 are used). 2. Machine with 32 CPUs and 128GB of memory. Quarantine size 4GB. Currently we free 1GB at at time. With new code we free 8MB at a time (1024 batches, ~512 are used). 3. Machine with 4096 CPUs and 1TB of memory. Quarantine size 32GB. Currently we free 8GB at at time. With new code we free 4MB at a time (16K batches, ~8K are used). Link: http://lkml.kernel.org/r/1478756952-18695-1-git-send-email-dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | kasan: support panic_on_warnDmitry Vyukov2016-12-121-0/+2
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If user sets panic_on_warn, he wants kernel to panic if there is anything barely wrong with the kernel. KASAN-detected errors are definitely not less benign than an arbitrary kernel WARNING. Panic after KASAN errors if panic_on_warn is set. We use this for continuous fuzzing where we want kernel to stop and reboot on any error. Link: http://lkml.kernel.org/r/1476694764-31986-1-git-send-email-dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | kasan: support use-after-scope detectionDmitry Vyukov2016-11-303-0/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Gcc revision 241896 implements use-after-scope detection. Will be available in gcc 7. Support it in KASAN. Gcc emits 2 new callbacks to poison/unpoison large stack objects when they go in/out of scope. Implement the callbacks and add a test. [dvyukov@google.com: v3] Link: http://lkml.kernel.org/r/1479998292-144502-1-git-send-email-dvyukov@google.com Link: http://lkml.kernel.org/r/1479226045-145148-1-git-send-email-dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: <stable@vger.kernel.org> [4.0+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | kasan: update kasan_global for gcc 7Dmitry Vyukov2016-11-301-0/+3
|/ | | | | | | | | | | | | | | | kasan_global struct is part of compiler/runtime ABI. gcc revision 241983 has added a new field to kasan_global struct. Update kernel definition of kasan_global struct to include the new field. Without this patch KASAN is broken with gcc 7. Link: http://lkml.kernel.org/r/1479219743-28682-1-git-send-email-dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: <stable@vger.kernel.org> [4.0+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kprobes: Unpoison stack in jprobe_return() for KASANDmitry Vyukov2016-10-161-3/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I observed false KSAN positives in the sctp code, when sctp uses jprobe_return() in jsctp_sf_eat_sack(). The stray 0xf4 in shadow memory are stack redzones: [ ] ================================================================== [ ] BUG: KASAN: stack-out-of-bounds in memcmp+0xe9/0x150 at addr ffff88005e48f480 [ ] Read of size 1 by task syz-executor/18535 [ ] page:ffffea00017923c0 count:0 mapcount:0 mapping: (null) index:0x0 [ ] flags: 0x1fffc0000000000() [ ] page dumped because: kasan: bad access detected [ ] CPU: 1 PID: 18535 Comm: syz-executor Not tainted 4.8.0+ #28 [ ] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ ] ffff88005e48f2d0 ffffffff82d2b849 ffffffff0bc91e90 fffffbfff10971e8 [ ] ffffed000bc91e90 ffffed000bc91e90 0000000000000001 0000000000000000 [ ] ffff88005e48f480 ffff88005e48f350 ffffffff817d3169 ffff88005e48f370 [ ] Call Trace: [ ] [<ffffffff82d2b849>] dump_stack+0x12e/0x185 [ ] [<ffffffff817d3169>] kasan_report+0x489/0x4b0 [ ] [<ffffffff817d31a9>] __asan_report_load1_noabort+0x19/0x20 [ ] [<ffffffff82d49529>] memcmp+0xe9/0x150 [ ] [<ffffffff82df7486>] depot_save_stack+0x176/0x5c0 [ ] [<ffffffff817d2031>] save_stack+0xb1/0xd0 [ ] [<ffffffff817d27f2>] kasan_slab_free+0x72/0xc0 [ ] [<ffffffff817d05b8>] kfree+0xc8/0x2a0 [ ] [<ffffffff85b03f19>] skb_free_head+0x79/0xb0 [ ] [<ffffffff85b0900a>] skb_release_data+0x37a/0x420 [ ] [<ffffffff85b090ff>] skb_release_all+0x4f/0x60 [ ] [<ffffffff85b11348>] consume_skb+0x138/0x370 [ ] [<ffffffff8676ad7b>] sctp_chunk_put+0xcb/0x180 [ ] [<ffffffff8676ae88>] sctp_chunk_free+0x58/0x70 [ ] [<ffffffff8677fa5f>] sctp_inq_pop+0x68f/0xef0 [ ] [<ffffffff8675ee36>] sctp_assoc_bh_rcv+0xd6/0x4b0 [ ] [<ffffffff8677f2c1>] sctp_inq_push+0x131/0x190 [ ] [<ffffffff867bad69>] sctp_backlog_rcv+0xe9/0xa20 [ ... ] [ ] Memory state around the buggy address: [ ] ffff88005e48f380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ ] ffff88005e48f400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ ] >ffff88005e48f480: f4 f4 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ ] ^ [ ] ffff88005e48f500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ ] ffff88005e48f580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ ] ================================================================== KASAN stack instrumentation poisons stack redzones on function entry and unpoisons them on function exit. If a function exits abnormally (e.g. with a longjmp like jprobe_return()), stack redzones are left poisoned. Later this leads to random KASAN false reports. Unpoison stack redzones in the frames we are going to jump over before doing actual longjmp in jprobe_return(). Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: kasan-dev@googlegroups.com Cc: surovegin@google.com Cc: rostedt@goodmis.org Link: http://lkml.kernel.org/r/1476454043-101898-1-git-send-email-dvyukov@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* kasan: remove the unnecessary WARN_ONCE from quarantine.cAlexander Potapenko2016-08-111-5/+2
| | | | | | | | | | | | | | | | | | It's quite unlikely that the user will so little memory that the per-CPU quarantines won't fit into the given fraction of the available memory. Even in that case he won't be able to do anything with the information given in the warning. Link: http://lkml.kernel.org/r/1470929182-101413-1-git-send-email-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Konovalov <adech.fo@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kuthonuzo Luruo <kuthonuzo.luruo@hpe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kasan: avoid overflowing quarantine size on low memory systemsAlexander Potapenko2016-08-021-2/+7
| | | | | | | | | | | | | | | If the total amount of memory assigned to quarantine is less than the amount of memory assigned to per-cpu quarantines, |new_quarantine_size| may overflow. Instead, set it to zero. [akpm@linux-foundation.org: cleanup: use WARN_ONCE return value] Link: http://lkml.kernel.org/r/1470063563-96266-1-git-send-email-glider@google.com Fixes: 55834c59098d ("mm: kasan: initial memory quarantine implementation") Signed-off-by: Alexander Potapenko <glider@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kasan: improve double-free reportsAndrey Ryabinin2016-08-023-18/+41
| | | | | | | | | | | | | | Currently we just dump stack in case of double free bug. Let's dump all info about the object that we have. [aryabinin@virtuozzo.com: change double free message per Alexander] Link: http://lkml.kernel.org/r/1470153654-30160-1-git-send-email-aryabinin@virtuozzo.com Link: http://lkml.kernel.org/r/1470062715-14077-6-git-send-email-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/kasan: get rid of ->state in struct kasan_alloc_metaAndrey Ryabinin2016-08-024-63/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | The state of object currently tracked in two places - shadow memory, and the ->state field in struct kasan_alloc_meta. We can get rid of the latter. The will save us a little bit of memory. Also, this allow us to move free stack into struct kasan_alloc_meta, without increasing memory consumption. So now we should always know when the last time the object was freed. This may be useful for long delayed use-after-free bugs. As a side effect this fixes following UBSAN warning: UBSAN: Undefined behaviour in mm/kasan/quarantine.c:102:13 member access within misaligned address ffff88000d1efebc for type 'struct qlist_node' which requires 8 byte alignment Link: http://lkml.kernel.org/r/1470062715-14077-5-git-send-email-aryabinin@virtuozzo.com Reported-by: kernel test robot <xiaolong.ye@intel.com> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/kasan: get rid of ->alloc_size in struct kasan_alloc_metaAndrey Ryabinin2016-08-023-8/+4
| | | | | | | | | | | | | | | | | | Size of slab object already stored in cache->object_size. Note, that kmalloc() internally rounds up size of allocation, so object_size may be not equal to alloc_size, but, usually we don't need to know the exact size of allocated object. In case if we need that information, we still can figure it out from the report. The dump of shadow memory allows to identify the end of allocated memory, and thereby the exact allocation size. Link: http://lkml.kernel.org/r/1470062715-14077-4-git-send-email-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/kasan, slub: don't disable interrupts when object leaves quarantineAndrey Ryabinin2016-08-021-2/+6
| | | | | | | | | | | SLUB doesn't require disabled interrupts to call ___cache_free(). Link: http://lkml.kernel.org/r/1470062715-14077-3-git-send-email-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/kasan: don't reduce quarantine in atomic contextsAndrey Ryabinin2016-08-021-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently we call quarantine_reduce() for ___GFP_KSWAPD_RECLAIM (implied by __GFP_RECLAIM) allocation. So, basically we call it on almost every allocation. quarantine_reduce() sometimes is heavy operation, and calling it with disabled interrupts may trigger hard LOCKUP: NMI watchdog: Watchdog detected hard LOCKUP on cpu 2irq event stamp: 1411258 Call Trace: <NMI> dump_stack+0x68/0x96 watchdog_overflow_callback+0x15b/0x190 __perf_event_overflow+0x1b1/0x540 perf_event_overflow+0x14/0x20 intel_pmu_handle_irq+0x36a/0xad0 perf_event_nmi_handler+0x2c/0x50 nmi_handle+0x128/0x480 default_do_nmi+0xb2/0x210 do_nmi+0x1aa/0x220 end_repeat_nmi+0x1a/0x1e <<EOE>> __kernel_text_address+0x86/0xb0 print_context_stack+0x7b/0x100 dump_trace+0x12b/0x350 save_stack_trace+0x2b/0x50 set_track+0x83/0x140 free_debug_processing+0x1aa/0x420 __slab_free+0x1d6/0x2e0 ___cache_free+0xb6/0xd0 qlist_free_all+0x83/0x100 quarantine_reduce+0x177/0x1b0 kasan_kmalloc+0xf3/0x100 Reduce the quarantine_reduce iff direct reclaim is allowed. Fixes: 55834c59098d("mm: kasan: initial memory quarantine implementation") Link: http://lkml.kernel.org/r/1470062715-14077-2-git-send-email-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Reported-by: Dave Jones <davej@codemonkey.org.uk> Acked-by: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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