[PATCH 5.9 029/152] io_uring: fix ITER_BVEC check

From: Greg Kroah-Hartman
Date: Tue Dec 01 2020 - 04:22:29 EST


From: Pavel Begunkov <asml.silence@xxxxxxxxx>

commit 9c3a205c5ffa36e96903c2e37eb5f41c0f03c43e upstream.

iov_iter::type is a bitmask that also keeps direction etc., so it
shouldn't be directly compared against ITER_*. Use proper helper.

Fixes: ff6165b2d7f6 ("io_uring: retain iov_iter state over io_read/io_write calls")
Reported-by: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # 5.9
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/io_uring.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2991,7 +2991,7 @@ static void io_req_map_rw(struct io_kioc
rw->free_iovec = NULL;
rw->bytes_done = 0;
/* can only be fixed buffers, no need to do anything */
- if (iter->type == ITER_BVEC)
+ if (iov_iter_is_bvec(iter))
return;
if (!iovec) {
unsigned iov_off = 0;