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| author | Al Viro <viro@zeniv.linux.org.uk> | 2016-08-17 23:19:01 -0400 |
|---|---|---|
| committer | Sasha Levin <alexander.levin@verizon.com> | 2016-10-02 21:12:56 -0400 |
| commit | e73af4fdf9383308283d5aa51bcf36941db25ada (patch) | |
| tree | da80bebccd26e2a7e5580bbf55dda12beeea2184 | |
| parent | a4b777858697ef94c097762a59c67958d5802959 (diff) | |
| download | lwn-e73af4fdf9383308283d5aa51bcf36941db25ada.tar.gz lwn-e73af4fdf9383308283d5aa51bcf36941db25ada.zip | |
asm-generic: make get_user() clear the destination on errors
[ Upstream commit 9ad18b75c2f6e4a78ce204e79f37781f8815c0fa ]
both for access_ok() failures and for faults halfway through
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
| -rw-r--r-- | include/asm-generic/uaccess.h | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h index 04e21a41796a..32901d11f8c4 100644 --- a/include/asm-generic/uaccess.h +++ b/include/asm-generic/uaccess.h @@ -230,14 +230,18 @@ extern int __put_user_bad(void) __attribute__((noreturn)); might_fault(); \ access_ok(VERIFY_READ, __p, sizeof(*ptr)) ? \ __get_user((x), (__typeof__(*(ptr)) *)__p) : \ - -EFAULT; \ + ((x) = (__typeof__(*(ptr)))0,-EFAULT); \ }) #ifndef __get_user_fn static inline int __get_user_fn(size_t size, const void __user *ptr, void *x) { - size = __copy_from_user(x, ptr, size); - return size ? -EFAULT : size; + size_t n = __copy_from_user(x, ptr, size); + if (unlikely(n)) { + memset(x + (size - n), 0, n); + return -EFAULT; + } + return 0; } #define __get_user_fn(sz, u, k) __get_user_fn(sz, u, k) |