diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/uaccess.h | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h index 39c7cf82b0c2..43844510d5d0 100644 --- a/include/linux/uaccess.h +++ b/include/linux/uaccess.h @@ -38,6 +38,7 @@ #else #define can_do_masked_user_access() 0 #define masked_user_access_begin(src) NULL + #define mask_user_address(src) (src) #endif /* @@ -159,19 +160,27 @@ _inline_copy_from_user(void *to, const void __user *from, unsigned long n) { unsigned long res = n; might_fault(); - if (!should_fail_usercopy() && likely(access_ok(from, n))) { + if (should_fail_usercopy()) + goto fail; + if (can_do_masked_user_access()) + from = mask_user_address(from); + else { + if (!access_ok(from, n)) + goto fail; /* * Ensure that bad access_ok() speculation will not * lead to nasty side effects *after* the copy is * finished: */ barrier_nospec(); - instrument_copy_from_user_before(to, from, n); - res = raw_copy_from_user(to, from, n); - instrument_copy_from_user_after(to, from, n, res); } - if (unlikely(res)) - memset(to + (n - res), 0, res); + instrument_copy_from_user_before(to, from, n); + res = raw_copy_from_user(to, from, n); + instrument_copy_from_user_after(to, from, n, res); + if (likely(!res)) + return 0; +fail: + memset(to + (n - res), 0, res); return res; } extern __must_check unsigned long |