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author | Al Viro <viro@zeniv.linux.org.uk> | 2016-08-18 21:31:41 -0400 |
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committer | Ben Hutchings <ben@decadent.org.uk> | 2016-11-20 01:01:38 +0000 |
commit | 6238800796e9581f7e3bbaed9c116f24110ce80a (patch) | |
tree | 5b5f4f0ffe44a51962ca965e85a7d5bd3d0bae81 | |
parent | d848857e80ab89474c7686d6a32d7ee594f0b706 (diff) | |
download | lwn-6238800796e9581f7e3bbaed9c116f24110ce80a.tar.gz lwn-6238800796e9581f7e3bbaed9c116f24110ce80a.zip |
ia64: copy_from_user() should zero the destination on access_ok() failure
commit a5e541f796f17228793694d64b507f5f57db4cd7 upstream.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.2: no calls to check_object_size()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r-- | arch/ia64/include/asm/uaccess.h | 20 |
1 files changed, 9 insertions, 11 deletions
diff --git a/arch/ia64/include/asm/uaccess.h b/arch/ia64/include/asm/uaccess.h index 449c8c0fa2bd..810926c56e31 100644 --- a/arch/ia64/include/asm/uaccess.h +++ b/arch/ia64/include/asm/uaccess.h @@ -262,17 +262,15 @@ __copy_from_user (void *to, const void __user *from, unsigned long count) __cu_len; \ }) -#define copy_from_user(to, from, n) \ -({ \ - void *__cu_to = (to); \ - const void __user *__cu_from = (from); \ - long __cu_len = (n); \ - \ - __chk_user_ptr(__cu_from); \ - if (__access_ok(__cu_from, __cu_len, get_fs())) \ - __cu_len = __copy_user((__force void __user *) __cu_to, __cu_from, __cu_len); \ - __cu_len; \ -}) +static inline unsigned long +copy_from_user(void *to, const void __user *from, unsigned long n) +{ + if (likely(__access_ok(from, n, get_fs()))) + n = __copy_user((__force void __user *) to, from, n); + else + memset(to, 0, n); + return n; +} #define __copy_in_user(to, from, size) __copy_user((to), (from), (size)) |