@@ -2341,6 +2341,7 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, struct sqe_submit *sqes,
if (!prev_was_link && link) {
io_queue_link_head(ctx, link, &link->submit, shadow_req);
link = NULL;
+ shadow_req = NULL;
}
prev_was_link = (sqes[i].sqe->flags & IOSQE_IO_LINK) != 0;
@@ -2524,6 +2525,7 @@ static int io_ring_submit(struct io_ring_ctx *ctx, unsigned int to_submit)
if (!prev_was_link && link) {
io_queue_link_head(ctx, link, &link->submit, shadow_req);
link = NULL;
+ shadow_req = NULL;
}
prev_was_link = (s.sqe->flags & IOSQE_IO_LINK) != 0;
There is a potential dangling pointer problem. we never clean shadow_req, if there are multiple link lists in this series of sqes, then the shadow_req will not reallocate, and continue to use the last one. but in the previous, his memory has been released, thus forming a dangling pointer. let's clean up him and make sure that every new link list can reapply for a new shadow_req. Fixes: 4fe2c96315 ("io_uring: add support for link with drain") Signed-off-by: Jackie Liu <liuyun01@kylinos.cn> --- fs/io_uring.c | 2 ++ 1 file changed, 2 insertions(+)