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| author | Al Viro <viro@zeniv.linux.org.uk> | 2016-08-17 23:19:01 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-09-24 10:09:39 +0200 |
| commit | cf4c19264e9b9c01b9d57fdc859f0e9aa5d138a5 (patch) | |
| tree | de5cf330c75fb174cbc9566960c5bd12f3843e42 /include | |
| parent | 42526dffda06eb2d8d4239f8cabd9fb09f84c9f2 (diff) | |
| download | lwn-cf4c19264e9b9c01b9d57fdc859f0e9aa5d138a5.tar.gz lwn-cf4c19264e9b9c01b9d57fdc859f0e9aa5d138a5.zip | |
asm-generic: make get_user() clear the destination on errors
commit 9ad18b75c2f6e4a78ce204e79f37781f8815c0fa upstream.
both for access_ok() failures and for faults halfway through
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
| -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 1bfa602958f2..c0019f76ee34 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) |