If IOSQE_ASYNC is set and we fail importing an iovec for a readv or
writev request, then we leave ->bytes_done uninitialized and hence the
eventual failure CQE posted can potentially have a random res value
rather than the expected -EINVAL.
Setup ->bytes_done before potentially failing, so we have a consistent
value if we fail the request early.
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: xingwei lee <xrivendell7@xxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
---
diff --git a/io_uring/rw.c b/io_uring/rw.c
index 4943d683508b..0c856726b15d 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -589,15 +589,19 @@ static inline int io_rw_prep_async(struct io_kiocb *req, int rw)
struct iovec *iov;
int ret;
+ iorw->bytes_done = 0;
+ iorw->free_iovec = NULL;
+
/* submission path, ->uring_lock should already be taken */
ret = io_import_iovec(rw, req, &iov, &iorw->s, 0);
if (unlikely(ret < 0))
return ret;
- iorw->bytes_done = 0;
- iorw->free_iovec = iov;
- if (iov)
+ if (iov) {
+ iorw->free_iovec = iov;
req->flags |= REQ_F_NEED_CLEANUP;
+ }
+
return 0;
}
--
Jens Axboe
