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* fs/binfmt_elf.c: allocate initialized memory in fill_thread_core_info()Alexander Potapenko2020-06-031-1/+1
| | | | | | | | | | | | | | | | | | | | [ Upstream commit 1d605416fb7175e1adf094251466caa52093b413 ] KMSAN reported uninitialized data being written to disk when dumping core. As a result, several kilobytes of kmalloc memory may be written to the core file and then read by a non-privileged user. Reported-by: sam <sunhaoyl@outlook.com> Signed-off-by: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/20200419100848.63472-1-glider@google.com Link: https://github.com/google/kmsan/issues/76 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
* binfmt_elf: Do not move brk for INTERP-less ET_EXECKees Cook2020-05-201-1/+2
| | | | | | | | | | | | | | | | | | | commit 7be3cb019db1cbd5fd5ffe6d64a23fefa4b6f229 upstream. When brk was moved for binaries without an interpreter, it should have been limited to ET_DYN only. In other words, the special case was an ET_DYN that lacks an INTERP, not just an executable that lacks INTERP. The bug manifested for giant static executables, where the brk would end up in the middle of the text area on 32-bit architectures. Reported-and-tested-by: Richard Kojedzinszky <richard@kojedz.in> Fixes: bbdc6076d2e5 ("binfmt_elf: move brk out of mmap when doing direct loader exec") Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binfmt_elf: move brk out of mmap when doing direct loader execKees Cook2020-05-201-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit bbdc6076d2e5d07db44e74c11b01a3e27ab90b32 upstream. Commmit eab09532d400 ("binfmt_elf: use ELF_ET_DYN_BASE only for PIE"), made changes in the rare case when the ELF loader was directly invoked (e.g to set a non-inheritable LD_LIBRARY_PATH, testing new versions of the loader), by moving into the mmap region to avoid both ET_EXEC and PIE binaries. This had the effect of also moving the brk region into mmap, which could lead to the stack and brk being arbitrarily close to each other. An unlucky process wouldn't get its requested stack size and stack allocations could end up scribbling on the heap. This is illustrated here. In the case of using the loader directly, brk (so helpfully identified as "[heap]") is allocated with the _loader_ not the binary. For example, with ASLR entirely disabled, you can see this more clearly: $ /bin/cat /proc/self/maps 555555554000-55555555c000 r-xp 00000000 ... /bin/cat 55555575b000-55555575c000 r--p 00007000 ... /bin/cat 55555575c000-55555575d000 rw-p 00008000 ... /bin/cat 55555575d000-55555577e000 rw-p 00000000 ... [heap] ... 7ffff7ff7000-7ffff7ffa000 r--p 00000000 ... [vvar] 7ffff7ffa000-7ffff7ffc000 r-xp 00000000 ... [vdso] 7ffff7ffc000-7ffff7ffd000 r--p 00027000 ... /lib/x86_64-linux-gnu/ld-2.27.so 7ffff7ffd000-7ffff7ffe000 rw-p 00028000 ... /lib/x86_64-linux-gnu/ld-2.27.so 7ffff7ffe000-7ffff7fff000 rw-p 00000000 ... 7ffffffde000-7ffffffff000 rw-p 00000000 ... [stack] $ /lib/x86_64-linux-gnu/ld-2.27.so /bin/cat /proc/self/maps ... 7ffff7bcc000-7ffff7bd4000 r-xp 00000000 ... /bin/cat 7ffff7bd4000-7ffff7dd3000 ---p 00008000 ... /bin/cat 7ffff7dd3000-7ffff7dd4000 r--p 00007000 ... /bin/cat 7ffff7dd4000-7ffff7dd5000 rw-p 00008000 ... /bin/cat 7ffff7dd5000-7ffff7dfc000 r-xp 00000000 ... /lib/x86_64-linux-gnu/ld-2.27.so 7ffff7fb2000-7ffff7fd6000 rw-p 00000000 ... 7ffff7ff7000-7ffff7ffa000 r--p 00000000 ... [vvar] 7ffff7ffa000-7ffff7ffc000 r-xp 00000000 ... [vdso] 7ffff7ffc000-7ffff7ffd000 r--p 00027000 ... /lib/x86_64-linux-gnu/ld-2.27.so 7ffff7ffd000-7ffff7ffe000 rw-p 00028000 ... /lib/x86_64-linux-gnu/ld-2.27.so 7ffff7ffe000-7ffff8020000 rw-p 00000000 ... [heap] 7ffffffde000-7ffffffff000 rw-p 00000000 ... [stack] The solution is to move brk out of mmap and into ELF_ET_DYN_BASE since nothing is there in the direct loader case (and ET_EXEC is still far away at 0x400000). Anything that ran before should still work (i.e. the ultimately-launched binary already had the brk very far from its text, so this should be no different from a COMPAT_BRK standpoint). The only risk I see here is that if someone started to suddenly depend on the entire memory space lower than the mmap region being available when launching binaries via a direct loader execs which seems highly unlikely, I'd hope: this would mean a binary would _not_ work when exec()ed normally. (Note that this is only done under CONFIG_ARCH_HAS_ELF_RANDOMIZATION when randomization is turned on.) Link: http://lkml.kernel.org/r/20190422225727.GA21011@beast Link: https://lkml.kernel.org/r/CAGXu5jJ5sj3emOT2QPxQkNQk0qbU6zEfu9=Omfhx_p0nCKPSjA@mail.gmail.com Fixes: eab09532d400 ("binfmt_elf: use ELF_ET_DYN_BASE only for PIE") Signed-off-by: Kees Cook <keescook@chromium.org> Reported-by: Ali Saidi <alisaidi@amazon.com> Cc: Ali Saidi <alisaidi@amazon.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binfmt_elf: Respect error return from `regset->active'Maciej W. Rozycki2018-09-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 2f819db565e82e5f73cd42b39925098986693378 ] The regset API documented in <linux/regset.h> defines -ENODEV as the result of the `->active' handler to be used where the feature requested is not available on the hardware found. However code handling core file note generation in `fill_thread_core_info' interpretes any non-zero result from the `->active' handler as the regset requested being active. Consequently processing continues (and hopefully gracefully fails later on) rather than being abandoned right away for the regset requested. Fix the problem then by making the code proceed only if a positive result is returned from the `->active' handler. Signed-off-by: Maciej W. Rozycki <macro@mips.com> Signed-off-by: Paul Burton <paul.burton@mips.com> Fixes: 4206d3aa1978 ("elf core dump: notes user_regset") Patchwork: https://patchwork.linux-mips.org/patch/19332/ Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-fsdevel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* fs, elf: make sure to page align bss in load_elf_libraryOscar Salvador2018-07-171-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | commit 24962af7e1041b7e50c1bc71d8d10dc678c556b5 upstream. The current code does not make sure to page align bss before calling vm_brk(), and this can lead to a VM_BUG_ON() in __mm_populate() due to the requested lenght not being correctly aligned. Let us make sure to align it properly. Kees: only applicable to CONFIG_USELIB kernels: 32-bit and configured for libc5. Link: http://lkml.kernel.org/r/20180705145539.9627-1-osalvador@techadventures.net Signed-off-by: Oscar Salvador <osalvador@suse.de> Reported-by: syzbot+5dcb560fe12aa5091c06@syzkaller.appspotmail.com Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Acked-by: Kees Cook <keescook@chromium.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Nicolas Pitre <nicolas.pitre@linaro.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>
* binfmt_elf: use ELF_ET_DYN_BASE only for PIEKees Cook2017-07-211-8/+51
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit eab09532d40090698b05a07c1c87f39fdbc5fab5 upstream. The ELF_ET_DYN_BASE position was originally intended to keep loaders away from ET_EXEC binaries. (For example, running "/lib/ld-linux.so.2 /bin/cat" might cause the subsequent load of /bin/cat into where the loader had been loaded.) With the advent of PIE (ET_DYN binaries with an INTERP Program Header), ELF_ET_DYN_BASE continued to be used since the kernel was only looking at ET_DYN. However, since ELF_ET_DYN_BASE is traditionally set at the top 1/3rd of the TASK_SIZE, a substantial portion of the address space is unused. For 32-bit tasks when RLIMIT_STACK is set to RLIM_INFINITY, programs are loaded above the mmap region. This means they can be made to collide (CVE-2017-1000370) or nearly collide (CVE-2017-1000371) with pathological stack regions. Lowering ELF_ET_DYN_BASE solves both by moving programs below the mmap region in all cases, and will now additionally avoid programs falling back to the mmap region by enforcing MAP_FIXED for program loads (i.e. if it would have collided with the stack, now it will fail to load instead of falling back to the mmap region). To allow for a lower ELF_ET_DYN_BASE, loaders (ET_DYN without INTERP) are loaded into the mmap region, leaving space available for either an ET_EXEC binary with a fixed location or PIE being loaded into mmap by the loader. Only PIE programs are loaded offset from ELF_ET_DYN_BASE, which means architectures can now safely lower their values without risk of loaders colliding with their subsequently loaded programs. For 64-bit, ELF_ET_DYN_BASE is best set to 4GB to allow runtimes to use the entire 32-bit address space for 32-bit pointers. Thanks to PaX Team, Daniel Micay, and Rik van Riel for inspiration and suggestions on how to implement this solution. Fixes: d1fd836dcf00 ("mm: split ET_DYN ASLR from mmap ASLR") Link: http://lkml.kernel.org/r/20170621173201.GA114489@beast Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Rik van Riel <riel@redhat.com> Cc: Daniel Micay <danielmicay@gmail.com> Cc: Qualys Security Advisory <qsa@qualys.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dmitry Safonov <dsafonov@virtuozzo.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Pratyush Anand <panand@redhat.com> Cc: Russell King <linux@armlinux.org.uk> 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* coredump: Ensure proper size of sparse core filesDave Kleikamp2017-07-051-0/+1
| | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 4d22c75d4c7b5c5f4bd31054f09103ee490878fd ] If the last section of a core file ends with an unmapped or zero page, the size of the file does not correspond with the last dump_skip() call. gdb complains that the file is truncated and can be confusing to users. After all of the vma sections are written, make sure that the file size is no smaller than the current file position. This problem can be demonstrated with gdb's bigcore testcase on the sparc architecture. Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* x86/coredump: Use pr_reg size, rather that TIF_IA32 flagDmitry Safonov2016-09-141-15/+8
| | | | | | | | | | | | | | | | | Killed PR_REG_SIZE and PR_REG_PTR macro as we can get regset size from regset view. I wish I could also kill PRSTATUS_SIZE nicely. Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com> Cc: 0x7f454c46@gmail.com Cc: linux-mm@kvack.org Cc: luto@kernel.org Cc: gorcunov@openvz.org Cc: xemul@virtuozzo.com Link: http://lkml.kernel.org/r/20160905133308.28234-5-dsafonov@virtuozzo.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* binfmt_elf: switch to new creds when switching to new mmLinus Torvalds2016-08-311-1/+1
| | | | | | | | | | | | | | | | | | | | | | | We used to delay switching to the new credentials until after we had mapped the executable (and possible elf interpreter). That was kind of odd to begin with, since the new executable will actually then _run_ with the new creds, but whatever. The bigger problem was that we also want to make sure that we turn off prof events and tracing before we start mapping the new executable state. So while this is a cleanup, it's also a fix for a possible information leak. Reported-by: Robert Święcki <robert@swiecki.net> Tested-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David Howells <dhowells@redhat.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Andy Lutomirski <luto@amacapital.net> Acked-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Willy Tarreau <w@1wt.eu> Cc: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* binfmt_elf: fix calculations for bss paddingKees Cook2016-08-021-16/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A double-bug exists in the bss calculation code, where an overflow can happen in the "last_bss - elf_bss" calculation, but vm_brk internally aligns the argument, underflowing it, wrapping back around safe. We shouldn't depend on these bugs staying in sync, so this cleans up the bss padding handling to avoid the overflow. This moves the bss padzero() before the last_bss > elf_bss case, since the zero-filling of the ELF_PAGE should have nothing to do with the relationship of last_bss and elf_bss: any trailing portion should be zeroed, and a zero size is already handled by padzero(). Then it handles the math on elf_bss vs last_bss correctly. These need to both be ELF_PAGE aligned to get the comparison correct, since that's the expected granularity of the mappings. Since elf_bss already had alignment-based padding happen in padzero(), the "start" of the new vm_brk() should be moved forward as done in the original code. However, since the "end" of the vm_brk() area will already become PAGE_ALIGNed in vm_brk() then last_bss should get aligned here to avoid hiding it as a side-effect. Additionally makes a cosmetic change to the initial last_bss calculation so it's easier to read in comparison to the load_addr calculation above it (i.e. the only difference is p_filesz vs p_memsz). Link: http://lkml.kernel.org/r/1468014494-25291-2-git-send-email-keescook@chromium.org Signed-off-by: Kees Cook <keescook@chromium.org> Reported-by: Hector Marco-Gisbert <hecmargi@upv.es> Cc: Ismael Ripoll Ripoll <iripoll@upv.es> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Chen Gang <gang.chen.5i5j@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.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>
* coredump: fix dumping through pipesMateusz Guzik2016-06-071-1/+1
| | | | | | | | | | | | | | | | | | The offset in the core file used to be tracked with ->written field of the coredump_params structure. The field was retired in favour of file->f_pos. However, ->f_pos is not maintained for pipes which leads to breakage. Restore explicit tracking of the offset in coredump_params. Introduce ->pos field for this purpose since ->written was already reused. Fixes: a00839395103 ("get rid of coredump_params->written"). Reported-by: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> Signed-off-by: Mateusz Guzik <mguzik@redhat.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* mm: remove more IS_ERR_VALUE abusesLinus Torvalds2016-05-271-6/+5
| | | | | | | | | | | | | | | | | | The do_brk() and vm_brk() return value was "unsigned long" and returned the starting address on success, and an error value on failure. The reasons are entirely historical, and go back to it basically behaving like the mmap() interface does. However, nobody actually wanted that interface, and it causes totally pointless IS_ERR_VALUE() confusion. What every single caller actually wants is just the simpler integer return of zero for success and negative error number on failure. So just convert to that much clearer and more common calling convention, and get rid of all the IS_ERR_VALUE() uses wrt vm_brk(). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, elf: handle vm_brk errorMichal Hocko2016-05-231-2/+5
| | | | | | | | | | | | | | load_elf_library doesn't handle vm_brk failure although nothing really indicates it cannot do that because the function is allowed to fail due to vm_mmap failures already. This might be not a problem now but later patch will make vm_brk killable (resp. mmap_sem for write waiting will become killable) and so the failure will be more probable. Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'work.misc' of ↵Linus Torvalds2016-05-181-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs cleanups from Al Viro: "Assorted cleanups and fixes all over the place" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: coredump: only charge written data against RLIMIT_CORE coredump: get rid of coredump_params->written ecryptfs_lookup(): try either only encrypted or plaintext name ecryptfs: avoid multiple aliases for directories bpf: reject invalid names right in ->lookup() __d_alloc(): treat NULL name as QSTR("/", 1) mtd: switch ubi_open_volume_path() to vfs_stat() mtd: switch open_mtd_by_chdev() to use of vfs_stat()
| * coredump: get rid of coredump_params->writtenOmar Sandoval2016-05-121-1/+1
| | | | | | | | | | | | | | cprm->written is redundant with cprm->file->f_pos, so use that instead. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macrosKirill A. Shutemov2016-04-041-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) 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>
* mm: ASLR: use get_random_long()Daniel Cashman2016-02-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace calls to get_random_int() followed by a cast to (unsigned long) with calls to get_random_long(). Also address shifting bug which, in case of x86 removed entropy mask for mmap_rnd_bits values > 31 bits. Signed-off-by: Daniel Cashman <dcashman@android.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: David S. Miller <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Nick Kralevich <nnk@google.com> Cc: Jeff Vander Stoep <jeffv@google.com> Cc: Mark Salyzyn <salyzyn@android.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ELF: Also pass any interpreter's file header to `arch_check_elf'Maciej W. Rozycki2016-01-201-1/+5
| | | | | | | | | | | | | | Also pass any interpreter's file header to `arch_check_elf' so that any architecture handler can have a look at it if needed. Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Matthew Fortune <Matthew.Fortune@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/11478/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* Merge branch 'for-linus-2' of ↵Linus Torvalds2015-11-111-6/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs update from Al Viro: - misc stable fixes - trivial kernel-doc and comment fixups - remove never-used block_page_mkwrite() wrapper function, and rename the function that is _actually_ used to not have double underscores. * 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: 9p: cache.h: Add #define of include guard vfs: remove stale comment in inode_operations vfs: remove unused wrapper block_page_mkwrite() binfmt_elf: Correct `arch_check_elf's description fs: fix writeback.c kernel-doc warnings fs: fix inode.c kernel-doc warning fs/pipe.c: return error code rather than 0 in pipe_write() fs/pipe.c: preserve alloc_file() error code binfmt_elf: Don't clobber passed executable's file header FS-Cache: Handle a write to the page immediately beyond the EOF marker cachefiles: perform test on s_blocksize when opening cache file. FS-Cache: Don't override netfs's primary_index if registering failed FS-Cache: Increase reference of parent after registering, netfs success debugfs: fix refcount imbalance in start_creating
| * binfmt_elf: Correct `arch_check_elf's descriptionMaciej W. Rozycki2015-11-111-1/+1
| | | | | | | | | | | | | | | | Correct `arch_check_elf's description, mistakenly copied and pasted from `arch_elf_pt_proc'. Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * binfmt_elf: Don't clobber passed executable's file headerMaciej W. Rozycki2015-11-111-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Do not clobber the buffer space passed from `search_binary_handler' and originally preloaded by `prepare_binprm' with the executable's file header by overwriting it with its interpreter's file header. Instead keep the buffer space intact and directly use the data structure locally allocated for the interpreter's file header, fixing a bug introduced in 2.1.14 with loadable module support (linux-mips.org commit beb11695 [Import of Linux/MIPS 2.1.14], predating kernel.org repo's history). Adjust the amount of data read from the interpreter's file accordingly. This was not an issue before loadable module support, because back then `load_elf_binary' was executed only once for a given ELF executable, whether the function succeeded or failed. With loadable module support supported and enabled, upon a failure of `load_elf_binary' -- which may for example be caused by architecture code rejecting an executable due to a missing hardware feature requested in the file header -- a module load is attempted and then the function reexecuted by `search_binary_handler'. With the executable's file header replaced with its interpreter's file header the executable can then be erroneously accepted in this subsequent attempt. Cc: stable@vger.kernel.org # all the way back Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | coredump: add DAX filtering for ELF coredumpsRoss Zwisler2015-11-091-0/+10
|/ | | | | | | | | | | | | | | | | | | | Add two new flags to the existing coredump mechanism for ELF files to allow us to explicitly filter DAX mappings. This is desirable because DAX mappings, like hugetlb mappings, have the potential to be very large. Update the coredump_filter documentation in Documentation/filesystems/proc.txt so that it addresses the new DAX coredump flags. Also update the documented default value of coredump_filter to be consistent with the core(5) man page. The documentation being updated talks about bit 4, Dump ELF headers, which is enabled if CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is turned on in the kernel config. This kernel config option defaults to "y" if both ELF binaries and coredump are enabled. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Acked-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* Merge branch 'for-linus' of ↵Linus Torvalds2015-07-041-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more vfs updates from Al Viro: "Assorted VFS fixes and related cleanups (IMO the most interesting in that part are f_path-related things and Eric's descriptor-related stuff). UFS regression fixes (it got broken last cycle). 9P fixes. fs-cache series, DAX patches, Jan's file_remove_suid() work" [ I'd say this is much more than "fixes and related cleanups". The file_table locking rule change by Eric Dumazet is a rather big and fundamental update even if the patch isn't huge. - Linus ] * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits) 9p: cope with bogus responses from server in p9_client_{read,write} p9_client_write(): avoid double p9_free_req() 9p: forgetting to cancel request on interrupted zero-copy RPC dax: bdev_direct_access() may sleep block: Add support for DAX reads/writes to block devices dax: Use copy_from_iter_nocache dax: Add block size note to documentation fs/file.c: __fget() and dup2() atomicity rules fs/file.c: don't acquire files->file_lock in fd_install() fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation vfs: avoid creation of inode number 0 in get_next_ino namei: make set_root_rcu() return void make simple_positive() public ufs: use dir_pages instead of ufs_dir_pages() pagemap.h: move dir_pages() over there remove the pointless include of lglock.h fs: cleanup slight list_entry abuse xfs: Correctly lock inode when removing suid and file capabilities fs: Call security_ops->inode_killpriv on truncate fs: Provide function telling whether file_remove_privs() will do anything ...
| * vfs: add file_path() helperMiklos Szeredi2015-06-231-2/+2
| | | | | | | | | | | | | | | | | | | | Turn d_path(&file->f_path, ...); into file_path(file, ...); Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | fs/binfmt_elf.c:load_elf_binary(): return -EINVAL on zero-length mappingsAndrew Morton2015-05-281-1/+1
|/ | | | | | | | | | load_elf_binary() returns `retval', not `error'. Fixes: a87938b2e246b81b4fb ("fs/binfmt_elf.c: fix bug in loading of PIE binaries") Reported-by: James Hogan <james.hogan@imgtec.com> Cc: Michael Davidson <md@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: fold arch_randomize_brk into ARCH_HAS_ELF_RANDOMIZEKees Cook2015-04-141-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The arch_randomize_brk() function is used on several architectures, even those that don't support ET_DYN ASLR. To avoid bulky extern/#define tricks, consolidate the support under CONFIG_ARCH_HAS_ELF_RANDOMIZE for the architectures that support it, while still handling CONFIG_COMPAT_BRK. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Hector Marco-Gisbert <hecmargi@upv.es> Cc: Russell King <linux@arm.linux.org.uk> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: "David A. Long" <dave.long@linaro.org> Cc: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Arun Chandran <achandran@mvista.com> Cc: Yann Droneaud <ydroneaud@opteya.com> Cc: Min-Hua Chen <orca.chen@gmail.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Alex Smith <alex@alex-smith.me.uk> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: Vineeth Vijayan <vvijayan@mvista.com> Cc: Jeff Bailey <jeffbailey@google.com> Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Behan Webster <behanw@converseincode.com> Cc: Ismael Ripoll <iripoll@upv.es> Cc: Jan-Simon Mller <dl9pf@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: split ET_DYN ASLR from mmap ASLRKees Cook2015-04-141-14/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes the "offset2lib" weakness in ASLR for arm, arm64, mips, powerpc, and x86. The problem is that if there is a leak of ASLR from the executable (ET_DYN), it means a leak of shared library offset as well (mmap), and vice versa. Further details and a PoC of this attack is available here: http://cybersecurity.upv.es/attacks/offset2lib/offset2lib.html With this patch, a PIE linked executable (ET_DYN) has its own ASLR region: $ ./show_mmaps_pie 54859ccd6000-54859ccd7000 r-xp ... /tmp/show_mmaps_pie 54859ced6000-54859ced7000 r--p ... /tmp/show_mmaps_pie 54859ced7000-54859ced8000 rw-p ... /tmp/show_mmaps_pie 7f75be764000-7f75be91f000 r-xp ... /lib/x86_64-linux-gnu/libc.so.6 7f75be91f000-7f75beb1f000 ---p ... /lib/x86_64-linux-gnu/libc.so.6 7f75beb1f000-7f75beb23000 r--p ... /lib/x86_64-linux-gnu/libc.so.6 7f75beb23000-7f75beb25000 rw-p ... /lib/x86_64-linux-gnu/libc.so.6 7f75beb25000-7f75beb2a000 rw-p ... 7f75beb2a000-7f75beb4d000 r-xp ... /lib64/ld-linux-x86-64.so.2 7f75bed45000-7f75bed46000 rw-p ... 7f75bed46000-7f75bed47000 r-xp ... 7f75bed47000-7f75bed4c000 rw-p ... 7f75bed4c000-7f75bed4d000 r--p ... /lib64/ld-linux-x86-64.so.2 7f75bed4d000-7f75bed4e000 rw-p ... /lib64/ld-linux-x86-64.so.2 7f75bed4e000-7f75bed4f000 rw-p ... 7fffb3741000-7fffb3762000 rw-p ... [stack] 7fffb377b000-7fffb377d000 r--p ... [vvar] 7fffb377d000-7fffb377f000 r-xp ... [vdso] The change is to add a call the newly created arch_mmap_rnd() into the ELF loader for handling ET_DYN ASLR in a separate region from mmap ASLR, as was already done on s390. Removes CONFIG_BINFMT_ELF_RANDOMIZE_PIE, which is no longer needed. Signed-off-by: Kees Cook <keescook@chromium.org> Reported-by: Hector Marco-Gisbert <hecmargi@upv.es> Cc: Russell King <linux@arm.linux.org.uk> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: "David A. Long" <dave.long@linaro.org> Cc: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Arun Chandran <achandran@mvista.com> Cc: Yann Droneaud <ydroneaud@opteya.com> Cc: Min-Hua Chen <orca.chen@gmail.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Alex Smith <alex@alex-smith.me.uk> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: Vineeth Vijayan <vvijayan@mvista.com> Cc: Jeff Bailey <jeffbailey@google.com> Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Behan Webster <behanw@converseincode.com> Cc: Ismael Ripoll <iripoll@upv.es> Cc: Jan-Simon Mller <dl9pf@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/binfmt_elf.c: fix bug in loading of PIE binariesMichael Davidson2015-04-141-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE enabled, and a normal top-down address allocation strategy, load_elf_binary() will attempt to map a PIE binary into an address range immediately below mm->mmap_base. Unfortunately, load_elf_ binary() does not take account of the need to allocate sufficient space for the entire binary which means that, while the first PT_LOAD segment is mapped below mm->mmap_base, the subsequent PT_LOAD segment(s) end up being mapped above mm->mmap_base into the are that is supposed to be the "gap" between the stack and the binary. Since the size of the "gap" on x86_64 is only guaranteed to be 128MB this means that binaries with large data segments > 128MB can end up mapping part of their data segment over their stack resulting in corruption of the stack (and the data segment once the binary starts to run). Any PIE binary with a data segment > 128MB is vulnerable to this although address randomization means that the actual gap between the stack and the end of the binary is normally greater than 128MB. The larger the data segment of the binary the higher the probability of failure. Fix this by calculating the total size of the binary in the same way as load_elf_interp(). Signed-off-by: Michael Davidson <md@google.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Kees Cook <keescook@chromium.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86, mm/ASLR: Fix stack randomization on 64-bit systemsHector Marco-Gisbert2015-02-191-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The issue is that the stack for processes is not properly randomized on 64 bit architectures due to an integer overflow. The affected function is randomize_stack_top() in file "fs/binfmt_elf.c": static unsigned long randomize_stack_top(unsigned long stack_top) { unsigned int random_variable = 0; if ((current->flags & PF_RANDOMIZE) && !(current->personality & ADDR_NO_RANDOMIZE)) { random_variable = get_random_int() & STACK_RND_MASK; random_variable <<= PAGE_SHIFT; } return PAGE_ALIGN(stack_top) + random_variable; return PAGE_ALIGN(stack_top) - random_variable; } Note that, it declares the "random_variable" variable as "unsigned int". Since the result of the shifting operation between STACK_RND_MASK (which is 0x3fffff on x86_64, 22 bits) and PAGE_SHIFT (which is 12 on x86_64): random_variable <<= PAGE_SHIFT; then the two leftmost bits are dropped when storing the result in the "random_variable". This variable shall be at least 34 bits long to hold the (22+12) result. These two dropped bits have an impact on the entropy of process stack. Concretely, the total stack entropy is reduced by four: from 2^28 to 2^30 (One fourth of expected entropy). This patch restores back the entropy by correcting the types involved in the operations in the functions randomize_stack_top() and stack_maxrandom_size(). The successful fix can be tested with: $ for i in `seq 1 10`; do cat /proc/self/maps | grep stack; done 7ffeda566000-7ffeda587000 rw-p 00000000 00:00 0 [stack] 7fff5a332000-7fff5a353000 rw-p 00000000 00:00 0 [stack] 7ffcdb7a1000-7ffcdb7c2000 rw-p 00000000 00:00 0 [stack] 7ffd5e2c4000-7ffd5e2e5000 rw-p 00000000 00:00 0 [stack] ... Once corrected, the leading bytes should be between 7ffc and 7fff, rather than always being 7fff. Signed-off-by: Hector Marco-Gisbert <hecmargi@upv.es> Signed-off-by: Ismael Ripoll <iripoll@upv.es> [ Rebased, fixed 80 char bugs, cleaned up commit message, added test example and CVE ] Signed-off-by: Kees Cook <keescook@chromium.org> Cc: <stable@vger.kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Fixes: CVE-2015-1593 Link: http://lkml.kernel.org/r/20150214173350.GA18393@www.outflux.net Signed-off-by: Borislav Petkov <bp@suse.de>
* Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds2014-12-111-62/+176
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull MIPS updates from Ralf Baechle: "This is an unusually large pull request for MIPS - in parts because lots of patches missed the 3.18 deadline but primarily because some folks opened the flood gates. - Retire the MIPS-specific phys_t with the generic phys_addr_t. - Improvments for the backtrace code used by oprofile. - Better backtraces on SMP systems. - Cleanups for the Octeon platform code. - Cleanups and fixes for the Loongson platform code. - Cleanups and fixes to the firmware library. - Switch ATH79 platform to use the firmware library. - Grand overhault to the SEAD3 and Malta interrupt code. - Move the GIC interrupt code to drivers/irqchip - Lots of GIC cleanups and updates to the GIC code to use modern IRQ infrastructures and features of the kernel. - OF documentation updates for the GIC bindings - Move GIC clocksource driver to drivers/clocksource - Merge GIC clocksource driver with clockevent driver. - Further updates to bring the GIC clocksource driver up to date. - R3000 TLB code cleanups - Improvments to the Loongson 3 platform code. - Convert pr_warning to pr_warn. - Merge a bunch of small lantiq and ralink fixes that have been staged/lingering inside the openwrt tree for a while. - Update archhelp for IP22/IP32 - Fix a number of issues for Loongson 1B. - New clocksource and clockevent driver for Loongson 1B. - Further work on clk handling for Loongson 1B. - Platform work for Broadcom BMIPS. - Error handling cleanups for TurboChannel. - Fixes and optimization to the microMIPS support. - Option to disable the FTLB. - Dump more relevant information on machine check exception - Change binfmt to allow arch to examine PT_*PROC headers - Support for new style FPU register model in O32 - VDSO randomization. - BCM47xx cleanups - BCM47xx reimplement the way the kernel accesses NVRAM information. - Random cleanups - Add support for ATH25 platforms - Remove pointless locking code in some PCI platforms. - Some improvments to EVA support - Minor Alchemy cleanup" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (185 commits) MIPS: Add MFHC0 and MTHC0 instructions to uasm. MIPS: Cosmetic cleanups of page table headers. MIPS: Add CP0 macros for extended EntryLo registers MIPS: Remove now unused definition of phys_t. MIPS: Replace use of phys_t with phys_addr_t. MIPS: Replace MIPS-specific 64BIT_PHYS_ADDR with generic PHYS_ADDR_T_64BIT PCMCIA: Alchemy Don't select 64BIT_PHYS_ADDR in Kconfig. MIPS: lib: memset: Clean up some MIPS{EL,EB} ifdefery MIPS: iomap: Use __mem_{read,write}{b,w,l} for MMIO MIPS: <asm/types.h> fix indentation. MAINTAINERS: Add entry for BMIPS multiplatform kernel MIPS: Enable VDSO randomization MIPS: Remove a temporary hack for debugging cache flushes in SMTC configuration MIPS: Remove declaration of obsolete arch_init_clk_ops() MIPS: atomic.h: Reformat to fit in 79 columns MIPS: Apply `.insn' to fixup labels throughout MIPS: Fix microMIPS LL/SC immediate offsets MIPS: Kconfig: Only allow 32-bit microMIPS builds MIPS: signal.c: Fix an invalid cast in ISA mode bit handling MIPS: mm: Only build one microassembler that is suitable ...
| * binfmt_elf: allow arch code to examine PT_LOPROC ... PT_HIPROC headersPaul Burton2014-11-241-2/+103
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | MIPS is introducing new variants of its O32 ABI which differ in their handling of floating point, in order to enable a gradual transition towards a world where mips32 binaries can take advantage of new hardware features only available when configured for certain FP modes. In order to do this ELF binaries are being augmented with a new section that indicates, amongst other things, the FP mode requirements of the binary. The presence & location of such a section is indicated by a program header in the PT_LOPROC ... PT_HIPROC range. In order to allow the MIPS architecture code to examine the program header & section in question, pass all program headers in this range to an architecture-specific arch_elf_pt_proc function. This function may return an error if the header is deemed invalid or unsuitable for the system, in which case that error will be returned from load_elf_binary and upwards through the execve syscall. A means is required for the architecture code to make a decision once it is known that all such headers have been seen, but before it is too late to return from an execve syscall. For this purpose the arch_check_elf function is added, and called once, after all PT_LOPROC to PT_HIPROC headers have been passed to arch_elf_pt_proc but before the code which invoked execve has been lost. This enables the architecture code to make a decision based upon all the headers present in an ELF binary and its interpreter, as is required to forbid conflicting FP ABI requirements between an ELF & its interpreter. In order to allow data to be stored throughout the calls to the above functions, struct arch_elf_state is introduced. Finally a variant of the SET_PERSONALITY macro is introduced which accepts a pointer to the struct arch_elf_state, allowing it to act based upon state observed from the architecture specific program headers. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/7679/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * binfmt_elf: load interpreter program headers earlierPaul Burton2014-11-241-18/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Load the program headers of an ELF interpreter early enough in load_elf_binary that they can be examined before it's too late to return an error from an exec syscall. This patch does not perform any such checking, it merely lays the groundwork for a further patch to do so. No functional change is intended. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/7675/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * binfmt_elf: Hoist ELF program header loading to a functionPaul Burton2014-11-241-43/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | load_elf_binary & load_elf_interp both load program headers from an ELF executable in the same way, duplicating the code. This patch introduces a helper function (load_elf_phdrs) which performs this common task & calls it from both load_elf_binary & load_elf_interp. In addition to reducing code duplication, this is part of preparing to load the ELF interpreter headers earlier such that they can be examined before it's too late to return an error from an exec syscall. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/7676/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* | fs/binfmt_elf.c: fix internal inconsistency relating to vma dump sizeJungseung Lee2014-12-101-18/+22
|/ | | | | | | | | | | | | | | | | | | | vma_dump_size() has been used several times on actual dumper and it is supposed to return the same value for the same vma. But vma_dump_size() could return different values for same vma. The known problem case is concurrent shared memory removal. If a vma is used for a shared memory and that shared memory is removed between writing program header and dumping vma memory, this will result in a dump file which is internally consistent. To fix the problem, we set baseline to get dump size and store the size into vma_filesz and always use the same vma dump size which is stored in vma_filsz. The consistnecy with reality is not actually guranteed, but it's tolerable since that is fully consistent with base line. Signed-off-by: Jungseung Lee <js07.lee@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* handle suicide on late failure exits in execve() in search_binary_handler()Al Viro2014-10-091-20/+5
| | | | | | | | ... rather than doing that in the guts of ->load_binary(). [updated to fix the bug spotted by Shentino - for SIGSEGV we really need something stronger than send_sig_info(); again, better do that in one place] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'x86/vdso' of ↵Linus Torvalds2014-06-051-0/+8
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next Pull x86 cdso updates from Peter Anvin: "Vdso cleanups and improvements largely from Andy Lutomirski. This makes the vdso a lot less ''special''" * 'x86/vdso' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/vdso, build: Make LE access macros clearer, host-safe x86/vdso, build: Fix cross-compilation from big-endian architectures x86/vdso, build: When vdso2c fails, unlink the output x86, vdso: Fix an OOPS accessing the HPET mapping w/o an HPET x86, mm: Replace arch_vma_name with vm_ops->name for vsyscalls x86, mm: Improve _install_special_mapping and fix x86 vdso naming mm, fs: Add vm_ops->name as an alternative to arch_vma_name x86, vdso: Fix an OOPS accessing the HPET mapping w/o an HPET x86, vdso: Remove vestiges of VDSO_PRELINK and some outdated comments x86, vdso: Move the vvar and hpet mappings next to the 64-bit vDSO x86, vdso: Move the 32-bit vdso special pages after the text x86, vdso: Reimplement vdso.so preparation in build-time C x86, vdso: Move syscall and sysenter setup into kernel/cpu/common.c x86, vdso: Clean up 32-bit vs 64-bit vdso params x86, mm: Ensure correct alignment of the fixmap
| * mm, fs: Add vm_ops->name as an alternative to arch_vma_nameAndy Lutomirski2014-05-201-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | arch_vma_name sucks. It's a silly hack, and it's annoying to implement correctly. In fact, AFAICS, even the straightforward x86 implementation is incorrect (I suspect that it breaks if the vdso mapping is split or gets remapped). This adds a new vm_ops->name operation that can replace it. The followup patches will remove all uses of arch_vma_name on x86, fixing a couple of annoyances in the process. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/2eee21791bb36a0a408c5c2bdb382a9e6a41ca4a.1400538962.git.luto@amacapital.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* | fs/binfmt_elf.c: fix bool assignementsFabian Frederick2014-06-041-2/+2
|/ | | | | | | | Fix coccinelle warnings. Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* exec: kill the unnecessary mm->def_flags setting in load_elf_binary()Alex Thorlton2014-04-071-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | load_elf_binary() sets current->mm->def_flags = def_flags and def_flags is always zero. Not only this looks strange, this is unnecessary because mm_init() has already set ->def_flags = 0. Signed-off-by: Alex Thorlton <athorlton@sgi.com> Suggested-by: Oleg Nesterov <oleg@redhat.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs, kernel: permit disabling the uselib syscallJosh Triplett2014-04-031-1/+8
| | | | | | | | | | | | | | | | | | | | | | | uselib hasn't been used since libc5; glibc does not use it. Support turning it off. When disabled, also omit the load_elf_library implementation from binfmt_elf.c, which only uselib invokes. bloat-o-meter: add/remove: 0/4 grow/shrink: 0/1 up/down: 0/-785 (-785) function old new delta padzero 39 36 -3 uselib_flags 20 - -20 sys_uselib 168 - -168 SyS_uselib 168 - -168 load_elf_library 426 - -426 The new CONFIG_USELIB defaults to `y'. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs: binfmt_elf: remove unused defines INTERPRETER_NONE and INTERPRETER_ELFTodor Minchev2014-01-231-3/+0
| | | | | | | | | These two defines are unused since the removal of the a.out interpreter support in the ELF loader in kernel 2.6.25 Signed-off-by: Todor Minchev <todor@minchev.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* elf{,_fdpic} coredump: get rid of pointless if (siginfo->si_signo)Al Viro2013-11-091-18/+15
| | | | | | we can't get to do_coredump() if that condition isn't satisfied... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* constify do_coredump() argumentAl Viro2013-11-091-2/+2
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* constify copy_siginfo_to_user{,32}()Al Viro2013-11-091-1/+1
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* new helper: dump_align()Al Viro2013-11-091-8/+2
| | | | | | dump_skip to given alignment... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* dump_skip(): dump_seek() replacement taking coredump_paramsAl Viro2013-11-091-2/+2
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* binfmt_elf: count notes towards coredump limitAl Viro2013-11-091-3/+0
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* switch elf_coredump_extra_notes_write() to dump_emit()Al Viro2013-11-091-4/+3
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* binfmt_elf: convert writing actual dump pages to dump_emit()Al Viro2013-11-091-11/+3
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* switch elf_core_write_extra_data() to dump_emit()Al Viro2013-11-091-1/+3
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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