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| author | Mark Rutland <mark.rutland@arm.com> | 2017-02-07 12:33:55 +0000 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2017-02-08 19:32:54 +0000 |
| commit | 76624175dcae6f7a808d345c0592908a15ca6975 (patch) | |
| tree | ba9f758b22dbf8498a3b2694fe63c0dfbc2f2e14 /arch/arm64/include | |
| parent | 21bdbb7102edeaebb5ec4ef530c8f442f7562c96 (diff) | |
| download | linux-76624175dcae6f7a808d345c0592908a15ca6975.tar.gz linux-76624175dcae6f7a808d345c0592908a15ca6975.tar.xz | |
arm64: uaccess: consistently check object sizes
Currently in arm64's copy_{to,from}_user, we only check the
source/destination object size if access_ok() tells us the user access
is permissible.
However, in copy_from_user() we'll subsequently zero any remainder on
the destination object. If we failed the access_ok() check, that applies
to the whole object size, which we didn't check.
To ensure that we catch that case, this patch hoists check_object_size()
to the start of copy_from_user(), matching __copy_from_user() and
__copy_to_user(). To make all of our uaccess copy primitives consistent,
the same is done to copy_to_user().
Cc: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/include')
| -rw-r--r-- | arch/arm64/include/asm/uaccess.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index 46da3ea638bb..5308d696311b 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -379,9 +379,9 @@ static inline unsigned long __must_check copy_from_user(void *to, const void __u { unsigned long res = n; kasan_check_write(to, n); + check_object_size(to, n, false); if (access_ok(VERIFY_READ, from, n)) { - check_object_size(to, n, false); res = __arch_copy_from_user(to, from, n); } if (unlikely(res)) @@ -392,9 +392,9 @@ static inline unsigned long __must_check copy_from_user(void *to, const void __u static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n) { kasan_check_read(from, n); + check_object_size(from, n, true); if (access_ok(VERIFY_WRITE, to, n)) { - check_object_size(from, n, true); n = __arch_copy_to_user(to, from, n); } return n; |