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| author | Andrey Ryabinin <aryabinin@virtuozzo.com> | 2018-08-10 13:25:58 +1000 |
|---|---|---|
| committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2018-08-13 04:11:46 +1000 |
| commit | aeeeaa7078d5c4989550406380f9a8c66d0f692f (patch) | |
| tree | 4ea649285c84a01868b27be715faa6b723dd7d00 /mm/fadvise.c | |
| parent | f5d47494f404f012c357105a00ef4a03abfb61d3 (diff) | |
| download | linux-next-aeeeaa7078d5c4989550406380f9a8c66d0f692f.tar.gz | |
mm/fadvise: fix signed overflow UBSAN complaint
Signed integer overflow is undefined according to the C standard. The
overflow in ksys_fadvise64_64() is deliberate, but since it is signed
overflow, UBSAN complains:
UBSAN: Undefined behaviour in mm/fadvise.c:76:10
signed integer overflow:
4 + 9223372036854775805 cannot be represented in type 'long long int'
Use unsigned types to do math. Unsigned overflow is defined so UBSAN will
not complain about it. This patch doesn't change generated code.
Link: http://lkml.kernel.org/r/20180629184453.7614-1-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reported-by: <icytxw@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Diffstat (limited to 'mm/fadvise.c')
| -rw-r--r-- | mm/fadvise.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/fadvise.c b/mm/fadvise.c index afa41491d324..1eaf2002d79a 100644 --- a/mm/fadvise.c +++ b/mm/fadvise.c @@ -73,7 +73,7 @@ int ksys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice) } /* Careful about overflows. Len == 0 means "as much as possible" */ - endbyte = offset + len; + endbyte = (u64)offset + (u64)len; if (!len || endbyte < len) endbyte = -1; else |