This is a note to let you know that I've just added the patch titled
io_uring/net: disable partial retries for recvmsg with cmsg
to the 6.3-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-disable-partial-retries-for-recvmsg-with-cmsg.patch
and it can be found in the queue-6.3 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 78d0d2063bab954d19a1696feae4c7706a626d48 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@xxxxxxxxx>
Date: Mon, 19 Jun 2023 09:41:05 -0600
Subject: io_uring/net: disable partial retries for recvmsg with cmsg
From: Jens Axboe <axboe@xxxxxxxxx>
commit 78d0d2063bab954d19a1696feae4c7706a626d48 upstream.
We cannot sanely handle partial retries for recvmsg if we have cmsg
attached. If we don't, then we'd just be overwriting the initial cmsg
header on retries. Alternatively we could increment and handle this
appropriately, but it doesn't seem worth the complication.
Move the MSG_WAITALL check into the non-multishot case while at it,
since MSG_WAITALL is explicitly disabled for multishot anyway.
Link: https://lore.kernel.org/io-uring/0b0d4411-c8fd-4272-770b-e030af6919a0@xxxxxxxxx/
Cc: stable@xxxxxxxxxxxxxxx # 5.10+
Reported-by: Stefan Metzmacher <metze@xxxxxxxxx>
Reviewed-by: Stefan Metzmacher <metze@xxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
io_uring/net.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -789,16 +789,19 @@ retry_multishot:
flags = sr->msg_flags;
if (force_nonblock)
flags |= MSG_DONTWAIT;
- if (flags & MSG_WAITALL)
- min_ret = iov_iter_count(&kmsg->msg.msg_iter);
kmsg->msg.msg_get_inq = 1;
- if (req->flags & REQ_F_APOLL_MULTISHOT)
+ if (req->flags & REQ_F_APOLL_MULTISHOT) {
ret = io_recvmsg_multishot(sock, sr, kmsg, flags,
&mshot_finished);
- else
+ } else {
+ /* disable partial retry for recvmsg with cmsg attached */
+ if (flags & MSG_WAITALL && !kmsg->msg.msg_controllen)
+ min_ret = iov_iter_count(&kmsg->msg.msg_iter);
+
ret = __sys_recvmsg_sock(sock, &kmsg->msg, sr->umsg,
kmsg->uaddr, flags);
+ }
if (ret < min_ret) {
if (ret == -EAGAIN && force_nonblock) {
Patches currently in stable-queue which might be from axboe@xxxxxxxxx are
queue-6.3/io_uring-net-clear-msg_controllen-on-partial-sendmsg-retry.patch
queue-6.3/io_uring-net-disable-partial-retries-for-recvmsg-with-cmsg.patch
