https://github.com/torvalds/linux
Revision ce56a86e2ade45d052b3228cdfebe913a1ae7381 authored by Craig Bergstrom on 19 October 2017, 19:28:56 UTC, committed by Ingo Molnar on 20 October 2017, 07:48:00 UTC
Currently, it is possible to mmap() any offset from /dev/mem. If a program mmaps() /dev/mem offsets outside of the addressable limits of a system, the page table can be corrupted by setting reserved bits. For example if you mmap() offset 0x0001000000000000 of /dev/mem on an x86_64 system with a 48-bit bus, the page fault handler will be called with error_code set to RSVD. The kernel then crashes with a page table corruption error. This change prevents this page table corruption on x86 by refusing to mmap offsets higher than the highest valid address in the system. Signed-off-by: Craig Bergstrom <craigb@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: dsafonov@virtuozzo.com Cc: kirill.shutemov@linux.intel.com Cc: mhocko@suse.com Cc: oleg@redhat.com Link: http://lkml.kernel.org/r/20171019192856.39672-1-craigb@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Tip revision: ce56a86e2ade45d052b3228cdfebe913a1ae7381 authored by Craig Bergstrom on 19 October 2017, 19:28:56 UTC
x86/mm: Limit mmap() of /dev/mem to valid physical addresses
x86/mm: Limit mmap() of /dev/mem to valid physical addresses
Tip revision: ce56a86
File | Mode | Size |
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Documentation | ||
arch | ||
block | ||
certs | ||
crypto | ||
drivers | ||
firmware | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.cocciconfig | -rw-r--r-- | 59 bytes |
.get_maintainer.ignore | -rw-r--r-- | 31 bytes |
.gitattributes | -rw-r--r-- | 30 bytes |
.gitignore | -rw-r--r-- | 1.3 KB |
.mailmap | -rw-r--r-- | 8.2 KB |
COPYING | -rw-r--r-- | 18.3 KB |
CREDITS | -rw-r--r-- | 96.1 KB |
Kbuild | -rw-r--r-- | 2.2 KB |
Kconfig | -rw-r--r-- | 252 bytes |
MAINTAINERS | -rw-r--r-- | 420.4 KB |
Makefile | -rw-r--r-- | 58.4 KB |
README | -rw-r--r-- | 722 bytes |
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