Following patch will add missing barrier_nospec() to
copy_from_user_iter().
Avoid it for architectures supporting masked user
accesses, the same way as done for copy_from_user() by
commit 0fc810ae3ae1 ("x86/uaccess: Avoid barrier_nospec()
in 64-bit copy_from_user()")
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
v2: New in v2
---
lib/iov_iter.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index f9193f952f49..48bd0cbce8c2 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -49,12 +49,16 @@ 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;
+
+ 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;
}
--
2.49.0
