[PATCH 6.6 114/396] io_uring/net: correctly handle multishot recvmsg retry setup

Greg Kroah-Hartman
2024-04-01T16:40:58Z

From: Jens Axboe <axboe@kernel.dk>

[ Upstream commit deaef31bc1ec7966698a427da8c161930830e1cf ]

If we loop for multishot receive on the initial attempt, and then abort
later on to wait for more, we miss a case where we should be copying the
io_async_msghdr from the stack to stable storage. This leads to the next
retry potentially failing, if the application had the msghdr on the
stack.

Cc: stable@vger.kernel.org
Fixes: 9bb66906f23e ("io_uring: support multishot in recvmsg")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
io_uring/net.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/io_uring/net.c b/io_uring/net.c
index 4aaeada03f1e7..386a6745ae32f 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -915,7 +915,8 @@ int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
kfree(kmsg->free_iov);
io_netmsg_recycle(req, issue_flags);
req->flags &= ~REQ_F_NEED_CLEANUP;
- }
+ } else if (ret == -EAGAIN)
+ return io_setup_async_msg(req, kmsg, issue_flags);

return ret;
}
--
2.43.0