Patch "io_uring/net: ensure async prep handlers always initialize ->done_io" has been added to the 6.8-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    io_uring/net: ensure async prep handlers always initialize ->done_io

to the 6.8-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     io_uring-net-ensure-async-prep-handlers-always-initi.patch
and it can be found in the queue-6.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit dc4905638f68b47c8cd9a9d5294298a16e61e9ff
Author: Jens Axboe <axboe@xxxxxxxxx>
Date:   Fri Mar 15 16:36:23 2024 -0600

    io_uring/net: ensure async prep handlers always initialize ->done_io
    
    [ Upstream commit f3a640cca951ef9715597e68f5363afc0f452a88 ]
    
    If we get a request with IOSQE_ASYNC set, then we first run the prep
    async handlers. But if we then fail setting it up and want to post
    a CQE with -EINVAL, we use ->done_io. This was previously guarded with
    REQ_F_PARTIAL_IO, and the normal setup handlers do set it up before any
    potential errors, but we need to cover the async setup too.
    
    Fixes: 9817ad85899f ("io_uring/net: remove dependency on REQ_F_PARTIAL_IO for sr->done_io")
    Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/io_uring/net.c b/io_uring/net.c
index 099ab92cca0b7..dbabe0058f1cb 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -311,7 +311,10 @@ int io_send_prep_async(struct io_kiocb *req)
 	struct io_async_msghdr *io;
 	int ret;
 
-	if (!zc->addr || req_has_async_data(req))
+	if (req_has_async_data(req))
+		return 0;
+	zc->done_io = 0;
+	if (!zc->addr)
 		return 0;
 	io = io_msg_alloc_async_prep(req);
 	if (!io)
@@ -338,8 +341,10 @@ static int io_setup_async_addr(struct io_kiocb *req,
 
 int io_sendmsg_prep_async(struct io_kiocb *req)
 {
+	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
 	int ret;
 
+	sr->done_io = 0;
 	if (!io_msg_alloc_async_prep(req))
 		return -ENOMEM;
 	ret = io_sendmsg_copy_hdr(req, req->async_data);
@@ -586,9 +591,11 @@ static int io_recvmsg_copy_hdr(struct io_kiocb *req,
 
 int io_recvmsg_prep_async(struct io_kiocb *req)
 {
+	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
 	struct io_async_msghdr *iomsg;
 	int ret;
 
+	sr->done_io = 0;
 	if (!io_msg_alloc_async_prep(req))
 		return -ENOMEM;
 	iomsg = req->async_data;