t/io_uring: avoid null-ptr dereference in case setup_ring fails

s->sq_ring.ring_entries and s->cq_ring.ring_entries will be NULL,
incase setup_ring fails. This will cause a segmentation fault. Avoid
dereferencing them in such a scenario.

Signed-off-by: Anuj Gupta <anuj20.g@samsung.com>
Link: https://lore.kernel.org/r/20230427194415.1160701-1-anuj20.g@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/t/io_uring.c b/t/io_uring.c
index 2f8d63fbe67e96dbb3b95fbf93f62317f122afe5..bf0aa26ece569983dbad73567c6221b482be1db0 100644 (file)
--- a/t/io_uring.c
+++ b/t/io_uring.c
@@ -1059,7 +1059,8 @@ static int submitter_init(struct submitter *s)
                err = 0;
        } else if (!aio) {
                err = setup_ring(s);
-               sprintf(buf, "Engine=io_uring, sq_ring=%d, cq_ring=%d\n", *s->sq_ring.ring_entries, *s->cq_ring.ring_entries);
+               if (!err)
+                       sprintf(buf, "Engine=io_uring, sq_ring=%d, cq_ring=%d\n", *s->sq_ring.ring_entries, *s->cq_ring.ring_entries);
        } else {
                sprintf(buf, "Engine=aio\n");
                err = setup_aio(s);