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authorMark Rutland <mark.rutland@arm.com>2017-02-07 12:33:55 +0000
committerWill Deacon <will.deacon@arm.com>2017-02-08 19:32:54 +0000
commit76624175dcae6f7a808d345c0592908a15ca6975 (patch)
treeba9f758b22dbf8498a3b2694fe63c0dfbc2f2e14 /arch/arm64/include/asm/uaccess.h
parentperf: add qcom l2 cache perf events driver (diff)
downloadlinux-dev-76624175dcae6f7a808d345c0592908a15ca6975.tar.xz
linux-dev-76624175dcae6f7a808d345c0592908a15ca6975.zip
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 '')
-rw-r--r--arch/arm64/include/asm/uaccess.h4
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;