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* lib/iov_iter: initialize "flags" in new pipe_bufferMax Kellermann2022-02-231-0/+2
| | | | | | | | | | | | | | | | | commit 9d2231c5d74e13b2a0546fee6737ee4446017903 upstream. The functions copy_page_to_iter_pipe() and push_pipe() can both allocate a new pipe_buffer, but the "flags" member initializer is missing. Fixes: 241699cd72a8 ("new iov_iter flavour: pipe-backed") To: Alexander Viro <viro@zeniv.linux.org.uk> To: linux-fsdevel@vger.kernel.org To: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Signed-off-by: Max Kellermann <max.kellermann@ionos.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ARM: 8800/1: use choice for kernel unwindersStefan Agner2022-01-291-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit f9b58e8c7d031b0daa5c9a9ee27f5a4028ba53ac upstream. While in theory multiple unwinders could be compiled in, it does not make sense in practise. Use a choice to make the unwinder selection mutually exclusive and mandatory. Already before this commit it has not been possible to deselect FRAME_POINTER. Remove the obsolete comment. Furthermore, to produce a meaningful backtrace with FRAME_POINTER enabled the kernel needs a specific function prologue: mov ip, sp stmfd sp!, {fp, ip, lr, pc} sub fp, ip, #4 To get to the required prologue gcc uses apcs and no-sched-prolog. This compiler options are not available on clang, and clang is not able to generate the required prologue. Make the FRAME_POINTER config symbol depending on !clang. Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Stefan Agner <stefan@agner.ch> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Anders Roxell <anders.roxell@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* lib/timerqueue: Rely on rbtree semantics for next timerDavidlohr Bueso2022-01-271-19/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 511885d7061eda3eb1faf3f57dcc936ff75863f1 upstream. Simplify the timerqueue code by using cached rbtrees and rely on the tree leftmost node semantics to get the timer with earliest expiration time. This is a drop in conversion, and therefore semantics remain untouched. The runtime overhead of cached rbtrees is be pretty much the same as the current head->next method, noting that when removing the leftmost node, a common operation for the timerqueue, the rb_next(leftmost) is O(1) as well, so the next timer will either be the right node or its parent. Therefore no extra pointer chasing. Finally, the size of the struct timerqueue_head remains the same. Passes several hours of rcutorture. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190724152323.bojciei3muvfxalm@linux-r8p5 [bwh: While this was supposed to be just refactoring, it also fixed a security flaw (CVE-2021-20317). Backported to 4.9: - Deleted code in timerqueue_del() is different before commit d852d39432f5 "timerqueue: Use rb_entry_safe() instead of open-coding it" - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* rbtree: cache leftmost node internallyDavidlohr Bueso2022-01-271-5/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit cd9e61ed1eebbcd5dfad59475d41ec58d9b64b6a upstream. Patch series "rbtree: Cache leftmost node internally", v4. A series to extending rbtrees to internally cache the leftmost node such that we can have fast overlap check optimization for all interval tree users[1]. The benefits of this series are that: (i) Unify users that do internal leftmost node caching. (ii) Optimize all interval tree users. (iii) Convert at least two new users (epoll and procfs) to the new interface. This patch (of 16): Red-black tree semantics imply that nodes with smaller or greater (or equal for duplicates) keys always be to the left and right, respectively. For the kernel this is extremely evident when considering our rb_first() semantics. Enabling lookups for the smallest node in the tree in O(1) can save a good chunk of cycles in not having to walk down the tree each time. To this end there are a few core users that explicitly do this, such as the scheduler and rtmutexes. There is also the desire for interval trees to have this optimization allowing faster overlap checking. This patch introduces a new 'struct rb_root_cached' which is just the root with a cached pointer to the leftmost node. The reason why the regular rb_root was not extended instead of adding a new structure was that this allows the user to have the choice between memory footprint and actual tree performance. The new wrappers on top of the regular rb_root calls are: - rb_first_cached(cached_root) -- which is a fast replacement for rb_first. - rb_insert_color_cached(node, cached_root, new) - rb_erase_cached(node, cached_root) In addition, augmented cached interfaces are also added for basic insertion and deletion operations; which becomes important for the interval tree changes. With the exception of the inserts, which adds a bool for updating the new leftmost, the interfaces are kept the same. To this end, porting rb users to the cached version becomes really trivial, and keeping current rbtree semantics for users that don't care about the optimization requires zero overhead. Link: http://lkml.kernel.org/r/20170719014603.19029-2-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* siphash: use _unaligned version by defaultArnd Bergmann2021-12-081-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit f7e5b9bfa6c8820407b64eabc1f29c9a87e8993d upstream. On ARM v6 and later, we define CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS because the ordinary load/store instructions (ldr, ldrh, ldrb) can tolerate any misalignment of the memory address. However, load/store double and load/store multiple instructions (ldrd, ldm) may still only be used on memory addresses that are 32-bit aligned, and so we have to use the CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS macro with care, or we may end up with a severe performance hit due to alignment traps that require fixups by the kernel. Testing shows that this currently happens with clang-13 but not gcc-11. In theory, any compiler version can produce this bug or other problems, as we are dealing with undefined behavior in C99 even on architectures that support this in hardware, see also https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100363. Fortunately, the get_unaligned() accessors do the right thing: when building for ARMv6 or later, the compiler will emit unaligned accesses using the ordinary load/store instructions (but avoid the ones that require 32-bit alignment). When building for older ARM, those accessors will emit the appropriate sequence of ldrb/mov/orr instructions. And on architectures that can truly tolerate any kind of misalignment, the get_unaligned() accessors resolve to the leXX_to_cpup accessors that operate on aligned addresses. Since the compiler will in fact emit ldrd or ldm instructions when building this code for ARM v6 or later, the solution is to use the unaligned accessors unconditionally on architectures where this is known to be fast. The _aligned version of the hash function is however still needed to get the best performance on architectures that cannot do any unaligned access in hardware. This new version avoids the undefined behavior and should produce the fastest hash on all architectures we support. Link: https://lore.kernel.org/linux-arm-kernel/20181008211554.5355-4-ard.biesheuvel@linaro.org/ Link: https://lore.kernel.org/linux-crypto/CAK8P3a2KfmmGDbVHULWevB0hv71P2oi2ZCHEAqT=8dQfa0=cqQ@mail.gmail.com/ Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Fixes: 2c956a60778c ("siphash: add cryptographically secure PRF") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* lib/xz: Validate the value before assigning it to an enum variableLasse Collin2021-11-261-3/+3
| | | | | | | | | | | | | | | | | | | | [ Upstream commit 4f8d7abaa413c34da9d751289849dbfb7c977d05 ] This might matter, for example, if the underlying type of enum xz_check was a signed char. In such a case the validation wouldn't have caught an unsupported header. I don't know if this problem can occur in the kernel on any arch but it's still good to fix it because some people might copy the XZ code to their own projects from Linux instead of the upstream XZ Embedded repository. This change may increase the code size by a few bytes. An alternative would have been to use an unsigned int instead of enum xz_check but using an enumeration looks cleaner. Link: https://lore.kernel.org/r/20211010213145.17462-3-xiang@kernel.org Signed-off-by: Lasse Collin <lasse.collin@tukaani.org> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* lib/xz: Avoid overlapping memcpy() with invalid input with in-place ↵Lasse Collin2021-11-262-3/+20
| | | | | | | | | | | | | | | | | | | | | decompression [ Upstream commit 83d3c4f22a36d005b55f44628f46cc0d319a75e8 ] With valid files, the safety margin described in lib/decompress_unxz.c ensures that these buffers cannot overlap. But if the uncompressed size of the input is larger than the caller thought, which is possible when the input file is invalid/corrupt, the buffers can overlap. Obviously the result will then be garbage (and usually the decoder will return an error too) but no other harm will happen when such an over-run occurs. This change only affects uncompressed LZMA2 chunks and so this should have no effect on performance. Link: https://lore.kernel.org/r/20211010213145.17462-2-xiang@kernel.org Signed-off-by: Lasse Collin <lasse.collin@tukaani.org> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* bpf/tests: Do not PASS tests without actually testing the resultJohan Almbladh2021-09-221-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 2b7e9f25e590726cca76700ebdb10e92a7a72ca1 ] Each test case can have a set of sub-tests, where each sub-test can run the cBPF/eBPF test snippet with its own data_size and expected result. Before, the end of the sub-test array was indicated by both data_size and result being zero. However, most or all of the internal eBPF tests has a data_size of zero already. When such a test also had an expected value of zero, the test was never run but reported as PASS anyway. Now the test runner always runs the first sub-test, regardless of the data_size and result values. The sub-test array zero-termination only applies for any additional sub-tests. There are other ways fix it of course, but this solution at least removes the surprise of eBPF tests with a zero result always succeeding. Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210721103822.3755111-1-johan.almbladh@anyfinetworks.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* bpf/tests: Fix copy-and-paste error in double word testJohan Almbladh2021-09-221-2/+2
| | | | | | | | | | | | [ Upstream commit ae7f47041d928b1a2f28717d095b4153c63cbf6a ] This test now operates on DW as stated instead of W, which was already covered by another test. Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210721104058.3755254-1-johan.almbladh@anyfinetworks.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* lib/string.c: add multibyte memset functionsMatthew Wilcox2021-08-041-0/+66
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 3b3c4babd898715926d24ae10aa64778ace33aae upstream. Patch series "Multibyte memset variations", v4. A relatively common idiom we're missing is a function to fill an area of memory with a pattern which is larger than a single byte. I first noticed this with a zram patch which wanted to fill a page with an 'unsigned long' value. There turn out to be quite a few places in the kernel which can benefit from using an optimised function rather than a loop; sometimes text size, sometimes speed, and sometimes both. The optimised PowerPC version (not included here) improves performance by about 30% on POWER8 on just the raw memset_l(). Most of the extra lines of code come from the three testcases I added. This patch (of 8): memset16(), memset32() and memset64() are like memset(), but allow the caller to fill the destination with a value larger than a single byte. memset_l() and memset_p() allow the caller to use unsigned long and pointer values respectively. Link: http://lkml.kernel.org/r/20170720184539.31609-2-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: David Miller <davem@davemloft.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Minchan Kim <minchan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Russell King <rmk+kernel@armlinux.org.uk> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Nobuhiro Iwamatsu (CIP) <nobuhiro1.iwamatsu@toshiba.co.jp> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* lib/decompress_unlz4.c: correctly handle zero-padding around initrds.Dimitri John Ledkov2021-07-201-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 2c484419efc09e7234c667aa72698cb79ba8d8ed ] lz4 compatible decompressor is simple. The format is underspecified and relies on EOF notification to determine when to stop. Initramfs buffer format[1] explicitly states that it can have arbitrary number of zero padding. Thus when operating without a fill function, be extra careful to ensure that sizes less than 4, or apperantly empty chunksizes are treated as EOF. To test this I have created two cpio initrds, first a normal one, main.cpio. And second one with just a single /test-file with content "second" second.cpio. Then i compressed both of them with gzip, and with lz4 -l. Then I created a padding of 4 bytes (dd if=/dev/zero of=pad4 bs=1 count=4). To create four testcase initrds: 1) main.cpio.gzip + extra.cpio.gzip = pad0.gzip 2) main.cpio.lz4 + extra.cpio.lz4 = pad0.lz4 3) main.cpio.gzip + pad4 + extra.cpio.gzip = pad4.gzip 4) main.cpio.lz4 + pad4 + extra.cpio.lz4 = pad4.lz4 The pad4 test-cases replicate the initrd load by grub, as it pads and aligns every initrd it loads. All of the above boot, however /test-file was not accessible in the initrd for the testcase #4, as decoding in lz4 decompressor failed. Also an error message printed which usually is harmless. Whith a patched kernel, all of the above testcases now pass, and /test-file is accessible. This fixes lz4 initrd decompress warning on every boot with grub. And more importantly this fixes inability to load multiple lz4 compressed initrds with grub. This patch has been shipping in Ubuntu kernels since January 2021. [1] ./Documentation/driver-api/early-userspace/buffer-format.rst BugLink: https://bugs.launchpad.net/bugs/1835660 Link: https://lore.kernel.org/lkml/20210114200256.196589-1-xnox@ubuntu.com/ # v0 Link: https://lkml.kernel.org/r/20210513104831.432975-1-dimitri.ledkov@canonical.com Signed-off-by: Dimitri John Ledkov <dimitri.ledkov@canonical.com> Cc: Kyungsik Lee <kyungsik.lee@lge.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Bongkyu Kim <bongkyu.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Sven Schmidt <4sschmid@informatik.uni-hamburg.de> Cc: Rajat Asthana <thisisrast7@gmail.com> Cc: Nick Terrell <terrelln@fb.com> Cc: Gao Xiang <hsiangkao@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* seq_buf: Fix overflow in seq_buf_putmem_hex()Yun Zhou2021-07-201-1/+3
| | | | | | | | | | | | | | | | | | | commit d3b16034a24a112bb83aeb669ac5b9b01f744bb7 upstream. There's two variables being increased in that loop (i and j), and i follows the raw data, and j follows what is being written into the buffer. We should compare 'i' to MAX_MEMHEX_BYTES or compare 'j' to HEX_CHARS. Otherwise, if 'j' goes bigger than HEX_CHARS, it will overflow the destination buffer. Link: https://lore.kernel.org/lkml/20210625122453.5e2fe304@oasis.local.home/ Link: https://lkml.kernel.org/r/20210626032156.47889-1-yun.zhou@windriver.com Cc: stable@vger.kernel.org Fixes: 5e3ca0ec76fce ("ftrace: introduce the "hex" output method") Signed-off-by: Yun Zhou <yun.zhou@windriver.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* seq_buf: Make trace_seq_putmem_hex() support data longer than 8Yun Zhou2021-07-201-1/+3
| | | | | | | | | | | | | | | | | | | commit 6a2cbc58d6c9d90cd74288cc497c2b45815bc064 upstream. Since the raw memory 'data' does not go forward, it will dump repeated data if the data length is more than 8. If we want to dump longer data blocks, we need to repeatedly call macro SEQ_PUT_HEX_FIELD. I think it is a bit redundant, and multiple function calls also affect the performance. Link: https://lore.kernel.org/lkml/20210625122453.5e2fe304@oasis.local.home/ Link: https://lkml.kernel.org/r/20210626032156.47889-2-yun.zhou@windriver.com Cc: stable@vger.kernel.org Fixes: 6d2289f3faa7 ("tracing: Make trace_seq_putmem_hex() more robust") Signed-off-by: Yun Zhou <yun.zhou@windriver.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* iov_iter_fault_in_readable() should do nothing in xarray caseAl Viro2021-07-201-1/+1
| | | | | | | | | | | | commit 0e8f0d67401589a141950856902c7d0ec8d9c985 upstream. ... and actually should just check it's given an iovec-backed iterator in the first place. Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* lib: stackdepot: turn depot_lock spinlock to raw_spinlockZqiang2021-05-221-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 78564b9434878d686c5f88c4488b20cccbcc42bc ] In RT system, the spin_lock will be replaced by sleepable rt_mutex lock, in __call_rcu(), disable interrupts before calling kasan_record_aux_stack(), will trigger this calltrace: BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:951 in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 19, name: pgdatinit0 Call Trace: ___might_sleep.cold+0x1b2/0x1f1 rt_spin_lock+0x3b/0xb0 stack_depot_save+0x1b9/0x440 kasan_save_stack+0x32/0x40 kasan_record_aux_stack+0xa5/0xb0 __call_rcu+0x117/0x880 __exit_signal+0xafb/0x1180 release_task+0x1d6/0x480 exit_notify+0x303/0x750 do_exit+0x678/0xcf0 kthread+0x364/0x4f0 ret_from_fork+0x22/0x30 Replace spinlock with raw_spinlock. Link: https://lkml.kernel.org/r/20210329084009.27013-1-qiang.zhang@windriver.com Signed-off-by: Zqiang <qiang.zhang@windriver.com> Reported-by: Andrew Halaney <ahalaney@redhat.com> Cc: Alexander Potapenko <glider@google.com> Cc: Gustavo A. R. Silva <gustavoars@kernel.org> Cc: Vijayanand Jitta <vjitta@codeaurora.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Cc: Yogesh Lal <ylal@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* kobject_uevent: remove warning in init_uevent_argv()Greg Kroah-Hartman2021-05-221-4/+5
| | | | | | | | | | | | | | | | | commit b4104180a2efb85f55e1ba1407885c9421970338 upstream. syzbot can trigger the WARN() in init_uevent_argv() which isn't the nicest as the code does properly recover and handle the error. So change the WARN() call to pr_warn() and provide some more information on what the buffer size that was needed. Link: https://lore.kernel.org/r/20201107082206.GA19079@kroah.com Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: linux-kernel@vger.kernel.org Reported-by: syzbot+92340f7b2b4789907fdb@syzkaller.appspotmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20210405094852.1348499-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* lib/string: Add strscpy_pad() functionTobin C. Harding2021-02-231-7/+40
| | | | | | | | | | | | | | | | | | | [ Upstream commit 458a3bf82df4fe1f951d0f52b1e0c1e9d5a88a3b ] We have a function to copy strings safely and we have a function to copy strings and zero the tail of the destination (if source string is shorter than destination buffer) but we do not have a function to do both at once. This means developers must write this themselves if they desire this functionality. This is a chore, and also leaves us open to off by one errors unnecessarily. Add a function that calls strscpy() then memset()s the tail to zero if the source string is shorter than the destination buffer. Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tobin C. Harding <tobin@kernel.org> Signed-off-by: Shuah Khan <shuah@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* lib/genalloc: fix the overflow when size is too bigHuang Shijie2021-01-121-12/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 36845663843fc59c5d794e3dc0641472e3e572da ] Some graphic card has very big memory on chip, such as 32G bytes. In the following case, it will cause overflow: pool = gen_pool_create(PAGE_SHIFT, NUMA_NO_NODE); ret = gen_pool_add(pool, 0x1000000, SZ_32G, NUMA_NO_NODE); va = gen_pool_alloc(pool, SZ_4G); The overflow occurs in gen_pool_alloc_algo_owner(): .... size = nbits << order; .... The @nbits is "int" type, so it will overflow. Then the gen_pool_avail() will return the wrong value. This patch converts some "int" to "unsigned long", and changes the compare code in while. Link: https://lkml.kernel.org/r/20201229060657.3389-1-sjhuang@iluvatar.ai Signed-off-by: Huang Shijie <sjhuang@iluvatar.ai> Reported-by: Shi Jiasheng <jiasheng.shi@iluvatar.ai> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* random32: make prandom_u32() output unpredictableGeorge Spelvin2020-11-181-179/+283
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit c51f8f88d705e06bd696d7510aff22b33eb8e638 upstream. Non-cryptographic PRNGs may have great statistical properties, but are usually trivially predictable to someone who knows the algorithm, given a small sample of their output. An LFSR like prandom_u32() is particularly simple, even if the sample is widely scattered bits. It turns out the network stack uses prandom_u32() for some things like random port numbers which it would prefer are *not* trivially predictable. Predictability led to a practical DNS spoofing attack. Oops. This patch replaces the LFSR with a homebrew cryptographic PRNG based on the SipHash round function, which is in turn seeded with 128 bits of strong random key. (The authors of SipHash have *not* been consulted about this abuse of their algorithm.) Speed is prioritized over security; attacks are rare, while performance is always wanted. Replacing all callers of prandom_u32() is the quick fix. Whether to reinstate a weaker PRNG for uses which can tolerate it is an open question. Commit f227e3ec3b5c ("random32: update the net random state on interrupt and activity") was an earlier attempt at a solution. This patch replaces it. Reported-by: Amit Klein <aksecurity@gmail.com> Cc: Willy Tarreau <w@1wt.eu> Cc: Eric Dumazet <edumazet@google.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: tytso@mit.edu Cc: Florian Westphal <fw@strlen.de> Cc: Marc Plumb <lkml.mplumb@gmail.com> Fixes: f227e3ec3b5c ("random32: update the net random state on interrupt and activity") Signed-off-by: George Spelvin <lkml@sdf.org> Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/ [ willy: partial reversal of f227e3ec3b5c; moved SIPROUND definitions to prandom.h for later use; merged George's prandom_seed() proposal; inlined siprand_u32(); replaced the net_rand_state[] array with 4 members to fix a build issue; cosmetic cleanups to make checkpatch happy; fixed RANDOM32_SELFTEST build ] [wt: backported to 4.9 -- various context adjustments; timer API change] Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* swiotlb: fix "x86: Don't panic if can not alloc buffer for swiotlb"Stefano Stabellini2020-11-181-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit e9696d259d0fb5d239e8c28ca41089838ea76d13 upstream. kernel/dma/swiotlb.c:swiotlb_init gets called first and tries to allocate a buffer for the swiotlb. It does so by calling memblock_alloc_low(PAGE_ALIGN(bytes), PAGE_SIZE); If the allocation must fail, no_iotlb_memory is set. Later during initialization swiotlb-xen comes in (drivers/xen/swiotlb-xen.c:xen_swiotlb_init) and given that io_tlb_start is != 0, it thinks the memory is ready to use when actually it is not. When the swiotlb is actually needed, swiotlb_tbl_map_single gets called and since no_iotlb_memory is set the kernel panics. Instead, if swiotlb-xen.c:xen_swiotlb_init knew the swiotlb hadn't been initialized, it would do the initialization itself, which might still succeed. Fix the panic by setting io_tlb_start to 0 on swiotlb initialization failure, and also by setting no_iotlb_memory to false on swiotlb initialization success. Fixes: ac2cbab21f31 ("x86: Don't panic if can not alloc buffer for swiotlb") Reported-by: Elliott Mitchell <ehem+xen@m5p.com> Tested-by: Elliott Mitchell <ehem+xen@m5p.com> Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: stable@vger.kernel.org Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Fonts: Replace discarded const qualifierLee Jones2020-11-1011-11/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 9522750c66c689b739e151fcdf895420dc81efc0 upstream. Commit 6735b4632def ("Fonts: Support FONT_EXTRA_WORDS macros for built-in fonts") introduced the following error when building rpc_defconfig (only this build appears to be affected): `acorndata_8x8' referenced in section `.text' of arch/arm/boot/compressed/ll_char_wr.o: defined in discarded section `.data' of arch/arm/boot/compressed/font.o `acorndata_8x8' referenced in section `.data.rel.ro' of arch/arm/boot/compressed/font.o: defined in discarded section `.data' of arch/arm/boot/compressed/font.o make[3]: *** [/scratch/linux/arch/arm/boot/compressed/Makefile:191: arch/arm/boot/compressed/vmlinux] Error 1 make[2]: *** [/scratch/linux/arch/arm/boot/Makefile:61: arch/arm/boot/compressed/vmlinux] Error 2 make[1]: *** [/scratch/linux/arch/arm/Makefile:317: zImage] Error 2 The .data section is discarded at link time. Reinstating acorndata_8x8 as const ensures it is still available after linking. Do the same for the other 12 built-in fonts as well, for consistency purposes. Cc: <stable@vger.kernel.org> Cc: Russell King <linux@armlinux.org.uk> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Fixes: 6735b4632def ("Fonts: Support FONT_EXTRA_WORDS macros for built-in fonts") Signed-off-by: Lee Jones <lee.jones@linaro.org> Co-developed-by: Peilin Ye <yepeilin.cs@gmail.com> Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20201102183242.2031659-1-yepeilin.cs@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* lib/crc32.c: fix trivial typo in preprocessor conditionTobias Jordan2020-10-291-1/+1
| | | | | | | | | | | | | | | | | | | | | [ Upstream commit 904542dc56524f921a6bab0639ff6249c01e775f ] Whether crc32_be needs a lookup table is chosen based on CRC_LE_BITS. Obviously, the _be function should be governed by the _BE_ define. This probably never pops up as it's hard to come up with a configuration where CRC_BE_BITS isn't the same as CRC_LE_BITS and as nobody is using bitwise CRC anyway. Fixes: 46c5801eaf86 ("crc32: bolt on crc32c") Signed-off-by: Tobias Jordan <kernel@cdqe.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Krzysztof Kozlowski <krzk@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lkml.kernel.org/r/20200923182122.GA3338@agrajag.zerfleddert.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* Fonts: Support FONT_EXTRA_WORDS macros for built-in fontsPeilin Ye2020-10-1411-49/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 6735b4632def0640dbdf4eb9f99816aca18c4f16 upstream. syzbot has reported an issue in the framebuffer layer, where a malicious user may overflow our built-in font data buffers. In order to perform a reliable range check, subsystems need to know `FONTDATAMAX` for each built-in font. Unfortunately, our font descriptor, `struct console_font` does not contain `FONTDATAMAX`, and is part of the UAPI, making it infeasible to modify it. For user-provided fonts, the framebuffer layer resolves this issue by reserving four extra words at the beginning of data buffers. Later, whenever a function needs to access them, it simply uses the following macros: Recently we have gathered all the above macros to <linux/font.h>. Let us do the same thing for built-in fonts, prepend four extra words (including `FONTDATAMAX`) to their data buffers, so that subsystems can use these macros for all fonts, no matter built-in or user-provided. This patch depends on patch "fbdev, newport_con: Move FONT_EXTRA_WORDS macros into linux/font.h". Cc: stable@vger.kernel.org Link: https://syzkaller.appspot.com/bug?id=08b8be45afea11888776f897895aef9ad1c3ecfd Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/ef18af00c35fb3cc826048a5f70924ed6ddce95b.1600953813.git.yepeilin.cs@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* random32: Restore __latent_entropy attribute on net_rand_stateThibaut Sautereau2020-10-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 09a6b0bc3be793ca8cba580b7992d73e9f68f15d ] Commit f227e3ec3b5c ("random32: update the net random state on interrupt and activity") broke compilation and was temporarily fixed by Linus in 83bdc7275e62 ("random32: remove net_rand_state from the latent entropy gcc plugin") by entirely moving net_rand_state out of the things handled by the latent_entropy GCC plugin. From what I understand when reading the plugin code, using the __latent_entropy attribute on a declaration was the wrong part and simply keeping the __latent_entropy attribute on the variable definition was the correct fix. Fixes: 83bdc7275e62 ("random32: remove net_rand_state from the latent entropy gcc plugin") Acked-by: Willy Tarreau <w@1wt.eu> Cc: Emese Revfy <re.emese@gmail.com> Signed-off-by: Thibaut Sautereau <thibaut.sautereau@ssi.gouv.fr> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* lib/string.c: implement stpcpyNick Desaulniers2020-10-011-0/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 1e1b6d63d6340764e00356873e5794225a2a03ea upstream. LLVM implemented a recent "libcall optimization" that lowers calls to `sprintf(dest, "%s", str)` where the return value is used to `stpcpy(dest, str) - dest`. This generally avoids the machinery involved in parsing format strings. `stpcpy` is just like `strcpy` except it returns the pointer to the new tail of `dest`. This optimization was introduced into clang-12. Implement this so that we don't observe linkage failures due to missing symbol definitions for `stpcpy`. Similar to last year's fire drill with: commit 5f074f3e192f ("lib/string.c: implement a basic bcmp") The kernel is somewhere between a "freestanding" environment (no full libc) and "hosted" environment (many symbols from libc exist with the same type, function signature, and semantics). As Peter Anvin notes, there's not really a great way to inform the compiler that you're targeting a freestanding environment but would like to opt-in to some libcall optimizations (see pr/47280 below), rather than opt-out. Arvind notes, -fno-builtin-* behaves slightly differently between GCC and Clang, and Clang is missing many __builtin_* definitions, which I consider a bug in Clang and am working on fixing. Masahiro summarizes the subtle distinction between compilers justly: To prevent transformation from foo() into bar(), there are two ways in Clang to do that; -fno-builtin-foo, and -fno-builtin-bar. There is only one in GCC; -fno-buitin-foo. (Any difference in that behavior in Clang is likely a bug from a missing __builtin_* definition.) Masahiro also notes: We want to disable optimization from foo() to bar(), but we may still benefit from the optimization from foo() into something else. If GCC implements the same transform, we would run into a problem because it is not -fno-builtin-bar, but -fno-builtin-foo that disables that optimization. In this regard, -fno-builtin-foo would be more future-proof than -fno-built-bar, but -fno-builtin-foo is still potentially overkill. We may want to prevent calls from foo() being optimized into calls to bar(), but we still may want other optimization on calls to foo(). It seems that compilers today don't quite provide the fine grain control over which libcall optimizations pseudo-freestanding environments would prefer. Finally, Kees notes that this interface is unsafe, so we should not encourage its use. As such, I've removed the declaration from any header, but it still needs to be exported to avoid linkage errors in modules. Reported-by: Sami Tolvanen <samitolvanen@google.com> Suggested-by: Andy Lavr <andy.lavr@gmail.com> Suggested-by: Arvind Sankar <nivedita@alum.mit.edu> Suggested-by: Joe Perches <joe@perches.com> Suggested-by: Kees Cook <keescook@chromium.org> Suggested-by: Masahiro Yamada <masahiroy@kernel.org> Suggested-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20200914161643.938408-1-ndesaulniers@google.com Link: https://bugs.llvm.org/show_bug.cgi?id=47162 Link: https://bugs.llvm.org/show_bug.cgi?id=47280 Link: https://github.com/ClangBuiltLinux/linux/issues/1126 Link: https://man7.org/linux/man-pages/man3/stpcpy.3.html Link: https://pubs.opengroup.org/onlinepubs/9699919799/functions/stpcpy.html Link: https://reviews.llvm.org/D85963 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: fix a BUG_ON in ddebug_describe_flagsJim Cromie2020-08-211-12/+11
| | | | | | | | | | | | | | | | | | | [ Upstream commit f678ce8cc3cb2ad29df75d8824c74f36398ba871 ] ddebug_describe_flags() currently fills a caller provided string buffer, after testing its size (also passed) in a BUG_ON. Fix this by replacing them with a known-big-enough string buffer wrapped in a struct, and passing that instead. Also simplify ddebug_describe_flags() flags parameter from a struct to a member in that struct, and hoist the member deref up to the caller. This makes the function reusable (soon) where flags are unpacked. Acked-by: <jbaron@akamai.com> Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20200719231058.1586423-8-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* random32: remove net_rand_state from the latent entropy gcc pluginLinus Torvalds2020-08-211-1/+1
| | | | | | | | | | | | | | | | | | | | | commit 83bdc7275e6206f560d247be856bceba3e1ed8f2 upstream. It turns out that the plugin right now ends up being really unhappy about the change from 'static' to 'extern' storage that happened in commit f227e3ec3b5c ("random32: update the net random state on interrupt and activity"). This is probably a trivial fix for the latent_entropy plugin, but for now, just remove net_rand_state from the list of things the plugin worries about. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Emese Revfy <re.emese@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* random32: update the net random state on interrupt and activityWilly Tarreau2020-08-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit f227e3ec3b5cad859ad15666874405e8c1bbc1d4 upstream. This modifies the first 32 bits out of the 128 bits of a random CPU's net_rand_state on interrupt or CPU activity to complicate remote observations that could lead to guessing the network RNG's internal state. Note that depending on some network devices' interrupt rate moderation or binding, this re-seeding might happen on every packet or even almost never. In addition, with NOHZ some CPUs might not even get timer interrupts, leaving their local state rarely updated, while they are running networked processes making use of the random state. For this reason, we also perform this update in update_process_times() in order to at least update the state when there is user or system activity, since it's the only case we care about. Reported-by: Amit Klein <aksecurity@gmail.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Eric Dumazet <edumazet@google.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* lib/zlib: remove outdated and incorrect pre-increment optimizationJann Horn2020-06-301-56/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit acaab7335bd6f0c0b54ce3a00bd7f18222ce0f5f ] The zlib inflate code has an old micro-optimization based on the assumption that for pre-increment memory accesses, the compiler will generate code that fits better into the processor's pipeline than what would be generated for post-increment memory accesses. This optimization was already removed in upstream zlib in 2016: https://github.com/madler/zlib/commit/9aaec95e8211 This optimization causes UB according to C99, which says in section 6.5.6 "Additive operators": "If both the pointer operand and the result point to elements of the same array object, or one past the last element of the array object, the evaluation shall not produce an overflow; otherwise, the behavior is undefined". This UB is not only a theoretical concern, but can also cause trouble for future work on compiler-based sanitizers. According to the zlib commit, this optimization also is not optimal anymore with modern compilers. Replace uses of OFF, PUP and UP_UNALIGNED with their definitions in the POSTINC case, and remove the macro definitions, just like in the upstream patch. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Mikhail Zaslonko <zaslonko@linux.ibm.com> Link: http://lkml.kernel.org/r/20200507123112.252723-1-jannh@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* lib/mpi: Fix 64-bit MIPS build with ClangNathan Chancellor2020-06-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 18f1ca46858eac22437819937ae44aa9a8f9f2fa ] When building 64r6_defconfig with CONFIG_MIPS32_O32 disabled and CONFIG_CRYPTO_RSA enabled: lib/mpi/generic_mpih-mul1.c:37:24: error: invalid use of a cast in a inline asm context requiring an l-value: remove the cast or build with -fheinous-gnu-extensions umul_ppmm(prod_high, prod_low, s1_ptr[j], s2_limb); ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ lib/mpi/longlong.h:664:22: note: expanded from macro 'umul_ppmm' : "=d" ((UDItype)(w0)) ~~~~~~~~~~^~~ lib/mpi/generic_mpih-mul1.c:37:13: error: invalid use of a cast in a inline asm context requiring an l-value: remove the cast or build with -fheinous-gnu-extensions umul_ppmm(prod_high, prod_low, s1_ptr[j], s2_limb); ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ lib/mpi/longlong.h:668:22: note: expanded from macro 'umul_ppmm' : "=d" ((UDItype)(w1)) ~~~~~~~~~~^~~ 2 errors generated. This special case for umul_ppmm for MIPS64r6 was added in commit bbc25bee37d2b ("lib/mpi: Fix umul_ppmm() for MIPS64r6"), due to GCC being inefficient and emitting a __multi3 intrinsic. There is no such issue with clang; with this patch applied, I can build this configuration without any problems and there are no link errors like mentioned in the commit above (which I can still reproduce with GCC 9.3.0 when that commit is reverted). Only use this definition when GCC is being used. This really should have been caught by commit b0c091ae04f67 ("lib/mpi: Eliminate unused umul_ppmm definitions for MIPS") when I was messing around in this area but I was not testing 64-bit MIPS at the time. Link: https://github.com/ClangBuiltLinux/linux/issues/885 Reported-by: Dmitry Golovin <dima@golovin.in> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
* ubsan: build ubsan.c more conservativelyArnd Bergmann2020-05-271-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit af700eaed0564d5d3963a7a51cb0843629d7fe3d upstream. objtool points out several conditions that it does not like, depending on the combination with other configuration options and compiler variants: stack protector: lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch()+0xbf: call to __stack_chk_fail() with UACCESS enabled lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch_v1()+0xbe: call to __stack_chk_fail() with UACCESS enabled stackleak plugin: lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch()+0x4a: call to stackleak_track_stack() with UACCESS enabled lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch_v1()+0x4a: call to stackleak_track_stack() with UACCESS enabled kasan: lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch()+0x25: call to memcpy() with UACCESS enabled lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch_v1()+0x25: call to memcpy() with UACCESS enabled The stackleak and kasan options just need to be disabled for this file as we do for other files already. For the stack protector, we already attempt to disable it, but this fails on clang because the check is mixed with the gcc specific -fno-conserve-stack option. According to Andrey Ryabinin, that option is not even needed, dropping it here fixes the stackprotector issue. Link: http://lkml.kernel.org/r/20190722125139.1335385-1-arnd@arndb.de Link: https://lore.kernel.org/lkml/20190617123109.667090-1-arnd@arndb.de/t/ Link: https://lore.kernel.org/lkml/20190722091050.2188664-1-arnd@arndb.de/t/ Fixes: d08965a27e84 ("x86/uaccess, ubsan: Fix UBSAN vs. SMAP") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/uaccess, ubsan: Fix UBSAN vs. SMAPPeter Zijlstra2020-05-271-0/+1
| | | | | | | | | | | | | | | | | | | | | | commit d08965a27e84ca090b504844d50c24fc98587b11 upstream. UBSAN can insert extra code in random locations; including AC=1 sections. Typically this code is not safe and needs wrapping. So far, only __ubsan_handle_type_mismatch* have been observed in AC=1 sections and therefore only those are annotated. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> [stable backport: only take the lib/Makefile change to resolve gcc-10 build issues] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* lib/mpi: Fix building for powerpc with clangNathan Chancellor2020-05-101-17/+17
| | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 5990cdee689c6885b27c6d969a3d58b09002b0bc ] 0day reports over and over on an powerpc randconfig with clang: lib/mpi/generic_mpih-mul1.c:37:13: error: invalid use of a cast in a inline asm context requiring an l-value: remove the cast or build with -fheinous-gnu-extensions Remove the superfluous casts, which have been done previously for x86 and arm32 in commit dea632cadd12 ("lib/mpi: fix build with clang") and commit 7b7c1df2883d ("lib/mpi/longlong.h: fix building with 32-bit x86"). Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://github.com/ClangBuiltLinux/linux/issues/991 Link: https://lore.kernel.org/r/20200413195041.24064-1-natechancellor@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
* lib/stackdepot.c: fix global out-of-bounds in stack_slabsAlexander Potapenko2020-02-281-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 305e519ce48e935702c32241f07d393c3c8fed3e ] Walter Wu has reported a potential case in which init_stack_slab() is called after stack_slabs[STACK_ALLOC_MAX_SLABS - 1] has already been initialized. In that case init_stack_slab() will overwrite stack_slabs[STACK_ALLOC_MAX_SLABS], which may result in a memory corruption. Link: http://lkml.kernel.org/r/20200218102950.260263-1-glider@google.com Fixes: cd11016e5f521 ("mm, kasan: stackdepot implementation. Enable stackdepot for SLAB") Signed-off-by: Alexander Potapenko <glider@google.com> Reported-by: Walter Wu <walter-zh.wu@mediatek.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* lib/scatterlist.c: adjust indentation in __sg_alloc_tableNathan Chancellor2020-02-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 4e456fee215677584cafa7f67298a76917e89c64 ] Clang warns: ../lib/scatterlist.c:314:5: warning: misleading indentation; statement is not part of the previous 'if' [-Wmisleading-indentation] return -ENOMEM; ^ ../lib/scatterlist.c:311:4: note: previous statement is here if (prv) ^ 1 warning generated. This warning occurs because there is a space before the tab on this line. Remove it so that the indentation is consistent with the Linux kernel coding style and clang no longer warns. Link: http://lkml.kernel.org/r/20191218033606.11942-1-natechancellor@gmail.com Link: https://github.com/ClangBuiltLinux/linux/issues/830 Fixes: edce6820a9fd ("scatterlist: prevent invalid free when alloc fails") Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* lib/test_kasan.c: fix memory leak in kmalloc_oob_krealloc_more()Gustavo A. R. Silva2020-02-141-0/+1
| | | | | | | | | | | | | | | | | | | | | commit 3e21d9a501bf99aee2e5835d7f34d8c823f115b5 upstream. In case memory resources for _ptr2_ were allocated, release them before return. Notice that in case _ptr1_ happens to be NULL, krealloc() behaves exactly like kmalloc(). Addresses-Coverity-ID: 1490594 ("Resource leak") Link: http://lkml.kernel.org/r/20200123160115.GA4202@embeddedor Fixes: 3f15801cdc23 ("lib: add kasan test module") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Reviewed-by: Dmitry Vyukov <dvyukov@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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* bitmap: Add bitmap_alloc(), bitmap_zalloc() and bitmap_free()Andy Shevchenko2020-01-291-0/+20
| | | | | | | | | | | | | | | | | | | commit c42b65e363ce97a828f81b59033c3558f8fa7f70 upstream. A lot of code become ugly because of open coding allocations for bitmaps. Introduce three helpers to allow users be more clear of intention and keep their code neat. Note, due to multiple circular dependencies we may not provide the helpers as inliners. For now we keep them exported and, perhaps, at some point in the future we will sort out header inclusion and inheritance. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Partially revert "kfifo: fix kfifo_alloc() and kfifo_init()"Linus Torvalds2020-01-291-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit ab9bb6318b0967671e0c9b6537c1537d51ca4f45 ] Commit dfe2a77fd243 ("kfifo: fix kfifo_alloc() and kfifo_init()") made the kfifo code round the number of elements up. That was good for __kfifo_alloc(), but it's actually wrong for __kfifo_init(). The difference? __kfifo_alloc() will allocate the rounded-up number of elements, but __kfifo_init() uses an allocation done by the caller. We can't just say "use more elements than the caller allocated", and have to round down. The good news? All the normal cases will be using power-of-two arrays anyway, and most users of kfifo's don't use kfifo_init() at all, but one of the helper macros to declare a KFIFO that enforce the proper power-of-two behavior. But it looks like at least ibmvscsis might be affected. The bad news? Will Deacon refers to an old thread and points points out that the memory ordering in kfifo's is questionable. See https://lore.kernel.org/lkml/20181211034032.32338-1-yuleixzhang@tencent.com/ for more. Fixes: dfe2a77fd243 ("kfifo: fix kfifo_alloc() and kfifo_init()") Reported-by: laokz <laokz@foxmail.com> Cc: Stefani Seibold <stefani@seibold.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: Greg KH <greg@kroah.com> Cc: Kees Cook <keescook@chromium.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* devres: allow const resource argumentsArnd Bergmann2020-01-291-1/+2
| | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 9dea44c91469512d346e638694c22c30a5273992 ] devm_ioremap_resource() does not currently take 'const' arguments, which results in a warning from the first driver trying to do it anyway: drivers/gpio/gpio-amd-fch.c: In function 'amd_fch_gpio_probe': drivers/gpio/gpio-amd-fch.c:171:49: error: passing argument 2 of 'devm_ioremap_resource' discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers] priv->base = devm_ioremap_resource(&pdev->dev, &amd_fch_gpio_iores); ^~~~~~~~~~~~~~~~~~~ Change the prototype to allow it, as there is no real reason not to. Fixes: 9bb2e0452508 ("gpio: amd: Make resource struct const") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20190628150049.1108048-1-arnd@arndb.de Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviwed-By: Enrico Weigelt <info@metux.net> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* kobject: Export kobject_get_unless_zero()Jan Kara2020-01-141-1/+4
| | | | | | | | | | | | | | | commit c70c176ff8c3ff0ac6ef9a831cd591ea9a66bd1a upstream. Make the function available for outside use and fortify it against NULL kobject. CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dma-debug: add a schedule point in debug_dma_dump_mappings()Eric Dumazet2020-01-041-0/+1
| | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 9ff6aa027dbb98755f0265695354f2dd07c0d1ce ] debug_dma_dump_mappings() can take a lot of cpu cycles : lpk43:/# time wc -l /sys/kernel/debug/dma-api/dump 163435 /sys/kernel/debug/dma-api/dump real 0m0.463s user 0m0.003s sys 0m0.459s Let's add a cond_resched() to avoid holding cpu for too long. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Corentin Labbe <clabbe@baylibre.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
* lib: raid6: fix awk build warningsGreg Kroah-Hartman2019-12-211-1/+1
| | | | | | | | | | | | | | | | | | | commit 702600eef73033ddd4eafcefcbb6560f3e3a90f7 upstream. Newer versions of awk spit out these fun warnings: awk: ../lib/raid6/unroll.awk:16: warning: regexp escape sequence `\#' is not a known regexp operator As commit 700c1018b86d ("x86/insn: Fix awk regexp warnings") showed, it turns out that there are a number of awk strings that do not need to be escaped and newer versions of awk now warn about this. Fix the string up so that no warning is produced. The exact same kernel module gets created before and after this patch, showing that it wasn't needed. Link: https://lore.kernel.org/r/20191206152600.GA75093@kroah.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* lib/genalloc.c: include vmalloc.hOlof Johansson2019-12-051-0/+1
| | | | | | | | | | | | | | | | | | | | [ Upstream commit 35004f2e55807a1a1491db24ab512dd2f770a130 ] Fixes build break on most ARM/ARM64 defconfigs: lib/genalloc.c: In function 'gen_pool_add_virt': lib/genalloc.c:190:10: error: implicit declaration of function 'vzalloc_node'; did you mean 'kzalloc_node'? lib/genalloc.c:190:8: warning: assignment to 'struct gen_pool_chunk *' from 'int' makes pointer from integer without a cast [-Wint-conversion] lib/genalloc.c: In function 'gen_pool_destroy': lib/genalloc.c:254:3: error: implicit declaration of function 'vfree'; did you mean 'kfree'? Fixes: 6862d2fc8185 ('lib/genalloc.c: use vzalloc_node() to allocate the bitmap') Cc: Huang Shijie <sjhuang@iluvatar.ai> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Alexey Skidanov <alexey.skidanov@intel.com> Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* lib/genalloc.c: use vzalloc_node() to allocate the bitmapHuang Shijie2019-12-051-2/+2
| | | | | | | | | | | | | | | | | | | [ Upstream commit 6862d2fc81859f88c1f3f660886427893f2b4f3f ] Some devices may have big memory on chip, such as over 1G. In some cases, the nbytes maybe bigger then 4M which is the bounday of the memory buddy system (4K default). So use vzalloc_node() to allocate the bitmap. Also use vfree to free it. Link: http://lkml.kernel.org/r/20181225015701.6289-1-sjhuang@iluvatar.ai Signed-off-by: Huang Shijie <sjhuang@iluvatar.ai> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexey Skidanov <alexey.skidanov@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* lib/genalloc.c: fix allocation of aligned buffer from non-aligned chunkAlexey Skidanov2019-12-051-8/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 52fbf1134d479234d7e64ba9dcbaea23405f229e ] gen_pool_alloc_algo() uses different allocation functions implementing different allocation algorithms. With gen_pool_first_fit_align() allocation function, the returned address should be aligned on the requested boundary. If chunk start address isn't aligned on the requested boundary, the returned address isn't aligned too. The only way to get properly aligned address is to initialize the pool with chunks aligned on the requested boundary. If want to have an ability to allocate buffers aligned on different boundaries (for example, 4K, 1MB, ...), the chunk start address should be aligned on the max possible alignment. This happens because gen_pool_first_fit_align() looks for properly aligned memory block without taking into account the chunk start address alignment. To fix this, we provide chunk start address to gen_pool_first_fit_align() and change its implementation such that it starts looking for properly aligned block with appropriate offset (exactly as is done in CMA). Link: https://lkml.kernel.org/lkml/a170cf65-6884-3592-1de9-4c235888cc8a@intel.com Link: http://lkml.kernel.org/r/1541690953-4623-1-git-send-email-alexey.skidanov@intel.com Signed-off-by: Alexey Skidanov <alexey.skidanov@intel.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Daniel Mentz <danielmentz@google.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Laura Abbott <labbott@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* dump_stack: avoid the livelock of the dump_lockKevin Hao2019-11-121-1/+6
| | | | | | | | | | | | | | | | | | | | | | | commit 5cbf2fff3bba8d3c6a4d47c1754de1cf57e2b01f upstream. In the current code, we use the atomic_cmpxchg() to serialize the output of the dump_stack(), but this implementation suffers the thundering herd problem. We have observed such kind of livelock on a Marvell cn96xx board(24 cpus) when heavily using the dump_stack() in a kprobe handler. Actually we can let the competitors to wait for the releasing of the lock before jumping to atomic_cmpxchg(). This will definitely mitigate the thundering herd problem. Thanks Linus for the suggestion. [akpm@linux-foundation.org: fix comment] Link: http://lkml.kernel.org/r/20191030031637.6025-1-haokexin@gmail.com Fixes: b58d977432c8 ("dump_stack: serialize the output from dump_stack()") Signed-off-by: Kevin Hao <haokexin@gmail.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kmemleak: increase DEBUG_KMEMLEAK_EARLY_LOG_SIZE default to 16KNicolas Boichat2019-10-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit b751c52bb587ae66f773b15204ef7a147467f4c7 ] The current default value (400) is too low on many systems (e.g. some ARM64 platform takes up 1000+ entries). syzbot uses 16000 as default value, and has proved to be enough on beefy configurations, so let's pick that value. This consumes more RAM on boot (each entry is 160 bytes, so in total ~2.5MB of RAM), but the memory would later be freed (early_log is __initdata). Link: http://lkml.kernel.org/r/20190730154027.101525-1-drinkcat@chromium.org Signed-off-by: Nicolas Boichat <drinkcat@chromium.org> Suggested-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Kees Cook <keescook@chromium.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Joe Lawrence <joe.lawrence@redhat.com> Cc: Uladzislau Rezki <urezki@gmail.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* siphash: implement HalfSipHash1-3 for hash tablesJason A. Donenfeld2019-08-252-4/+415
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 1ae2324f732c9c4e2fa4ebd885fa1001b70d52e1 upstream. HalfSipHash, or hsiphash, is a shortened version of SipHash, which generates 32-bit outputs using a weaker 64-bit key. It has *much* lower security margins, and shouldn't be used for anything too sensitive, but it could be used as a hashtable key function replacement, if the output is never exposed, and if the security requirement is not too high. The goal is to make this something that performance-critical jhash users would be willing to use. On 64-bit machines, HalfSipHash1-3 is slower than SipHash1-3, so we alias SipHash1-3 to HalfSipHash1-3 on those systems. 64-bit x86_64: [ 0.509409] test_siphash: SipHash2-4 cycles: 4049181 [ 0.510650] test_siphash: SipHash1-3 cycles: 2512884 [ 0.512205] test_siphash: HalfSipHash1-3 cycles: 3429920 [ 0.512904] test_siphash: JenkinsHash cycles: 978267 So, we map hsiphash() -> SipHash1-3 32-bit x86: [ 0.509868] test_siphash: SipHash2-4 cycles: 14812892 [ 0.513601] test_siphash: SipHash1-3 cycles: 9510710 [ 0.515263] test_siphash: HalfSipHash1-3 cycles: 3856157 [ 0.515952] test_siphash: JenkinsHash cycles: 1148567 So, we map hsiphash() -> HalfSipHash1-3 hsiphash() is roughly 3 times slower than jhash(), but comes with a considerable security improvement. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Jean-Philippe Aumasson <jeanphilippe.aumasson@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 4.9 to avoid regression for WireGuard with only half the siphash API present] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* siphash: add cryptographically secure PRFJason A. Donenfeld2019-08-254-5/+369
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 2c956a60778cbb6a27e0c7a8a52a91378c90e1d1 upstream. SipHash is a 64-bit keyed hash function that is actually a cryptographically secure PRF, like HMAC. Except SipHash is super fast, and is meant to be used as a hashtable keyed lookup function, or as a general PRF for short input use cases, such as sequence numbers or RNG chaining. For the first usage: There are a variety of attacks known as "hashtable poisoning" in which an attacker forms some data such that the hash of that data will be the same, and then preceeds to fill up all entries of a hashbucket. This is a realistic and well-known denial-of-service vector. Currently hashtables use jhash, which is fast but not secure, and some kind of rotating key scheme (or none at all, which isn't good). SipHash is meant as a replacement for jhash in these cases. There are a modicum of places in the kernel that are vulnerable to hashtable poisoning attacks, either via userspace vectors or network vectors, and there's not a reliable mechanism inside the kernel at the moment to fix it. The first step toward fixing these issues is actually getting a secure primitive into the kernel for developers to use. Then we can, bit by bit, port things over to it as deemed appropriate. While SipHash is extremely fast for a cryptographically secure function, it is likely a bit slower than the insecure jhash, and so replacements will be evaluated on a case-by-case basis based on whether or not the difference in speed is negligible and whether or not the current jhash usage poses a real security risk. For the second usage: A few places in the kernel are using MD5 or SHA1 for creating secure sequence numbers, syn cookies, port numbers, or fast random numbers. SipHash is a faster and more fitting, and more secure replacement for MD5 in those situations. Replacing MD5 and SHA1 with SipHash for these uses is obvious and straight-forward, and so is submitted along with this patch series. There shouldn't be much of a debate over its efficacy. Dozens of languages are already using this internally for their hash tables and PRFs. Some of the BSDs already use this in their kernels. SipHash is a widely known high-speed solution to a widely known set of problems, and it's time we catch-up. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Jean-Philippe Aumasson <jeanphilippe.aumasson@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: David Laight <David.Laight@aculab.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 4.9 as dependency of commits df453700e8d8 "inet: switch IP ID generator to siphash" and 3c79107631db "netfilter: ctnetlink: don't use conntrack/expect object addresses as id"] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* lib/strscpy: Shut up KASAN false-positives in strscpy()Andrey Ryabinin2019-08-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 1a3241ff10d038ecd096d03380327f2a0b5840a6 ] strscpy() performs the word-at-a-time optimistic reads. So it may may access the memory past the end of the object, which is perfectly fine since strscpy() doesn't use that (past-the-end) data and makes sure the optimistic read won't cross a page boundary. Use new read_word_at_a_time() to shut up the KASAN. Note that this potentially could hide some bugs. In example bellow, stscpy() will copy more than we should (1-3 extra uninitialized bytes): char dst[8]; char *src; src = kmalloc(5, GFP_KERNEL); memset(src, 0xff, 5); strscpy(dst, src, 8); Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
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