diff options
Diffstat (limited to 'lib/iov_iter.c')
| -rw-r--r-- | lib/iov_iter.c | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 2fe66a6b8789..896760bad455 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -49,12 +49,24 @@ size_t copy_from_user_iter(void __user *iter_from, size_t progress, if (should_fail_usercopy()) return len; - if (access_ok(iter_from, len)) { - to += progress; - instrument_copy_from_user_before(to, iter_from, len); - res = raw_copy_from_user(to, iter_from, len); - instrument_copy_from_user_after(to, iter_from, len, res); + if (can_do_masked_user_access()) { + iter_from = mask_user_address(iter_from); + } else { + if (!access_ok(iter_from, len)) + return res; + + /* + * Ensure that bad access_ok() speculation will not + * lead to nasty side effects *after* the copy is + * finished: + */ + barrier_nospec(); } + to += progress; + instrument_copy_from_user_before(to, iter_from, len); + res = raw_copy_from_user(to, iter_from, len); + instrument_copy_from_user_after(to, iter_from, len, res); + return res; } |