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| author | Eric Biggers | 2016-08-19 21:15:22 +0200 |
|---|---|---|
| committer | Kees Cook | 2016-08-23 04:07:55 +0200 |
| commit | 7329a655875a2f4bd6984fe8a7e00a6981e802f3 (patch) | |
| tree | 5c77614be62600da9d02d3b57709280e91e7292d /kernel/audit_watch.c | |
| parent | Merge tag 'arc-4.8-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/gi... (diff) | |
| download | kernel-qcow2-linux-7329a655875a2f4bd6984fe8a7e00a6981e802f3.tar.gz kernel-qcow2-linux-7329a655875a2f4bd6984fe8a7e00a6981e802f3.tar.xz kernel-qcow2-linux-7329a655875a2f4bd6984fe8a7e00a6981e802f3.zip | |
usercopy: avoid potentially undefined behavior in pointer math
check_bogus_address() checked for pointer overflow using this expression,
where 'ptr' has type 'const void *':
ptr + n < ptr
Since pointer wraparound is undefined behavior, gcc at -O2 by default
treats it like the following, which would not behave as intended:
(long)n < 0
Fortunately, this doesn't currently happen for kernel code because kernel
code is compiled with -fno-strict-overflow. But the expression should be
fixed anyway to use well-defined integer arithmetic, since it could be
treated differently by different compilers in the future or could be
reported by tools checking for undefined behavior.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'kernel/audit_watch.c')
0 files changed, 0 insertions, 0 deletions