This is a note to let you know that I've just added the patch titled
io_uring/net: harden multishot termination case for recv
to the 6.1-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-harden-multishot-termination-case-for-r.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d159acd607233902418598c0830ee8386b5f65db
Author: Jens Axboe <axboe@xxxxxxxxx>
Date: Thu Sep 26 07:08:10 2024 -0600
io_uring/net: harden multishot termination case for recv
[ Upstream commit c314094cb4cfa6fc5a17f4881ead2dfebfa717a7 ]
If the recv returns zero, or an error, then it doesn't matter if more
data has already been received for this buffer. A condition like that
should terminate the multishot receive. Rather than pass in the
collected return value, pass in whether to terminate or keep the recv
going separately.
Note that this isn't a bug right now, as the only way to get there is
via setting MSG_WAITALL with multishot receive. And if an application
does that, then -EINVAL is returned anyway. But it seems like an easy
bug to introduce, so let's make it a bit more explicit.
Link: https://github.com/axboe/liburing/issues/1246
Cc: stable@xxxxxxxxxxxxxxx
Fixes: b3fdea6ecb55 ("io_uring: multishot recv")
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 48404bd330017..f41acabf7b4a5 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -893,6 +893,7 @@ int io_recv(struct io_kiocb *req, unsigned int issue_flags)
int ret, min_ret = 0;
bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
size_t len = sr->len;
+ bool mshot_finished;
if (!(req->flags & REQ_F_POLLED) &&
(sr->flags & IORING_RECVSEND_POLL_FIRST))
@@ -957,6 +958,7 @@ int io_recv(struct io_kiocb *req, unsigned int issue_flags)
req_set_fail(req);
}
+ mshot_finished = ret <= 0;
if (ret > 0)
ret += sr->done_io;
else if (sr->done_io)
@@ -968,7 +970,7 @@ int io_recv(struct io_kiocb *req, unsigned int issue_flags)
if (msg.msg_inq)
cflags |= IORING_CQE_F_SOCK_NONEMPTY;
- if (!io_recv_finish(req, &ret, cflags, ret <= 0, issue_flags))
+ if (!io_recv_finish(req, &ret, cflags, mshot_finished, issue_flags))
goto retry_multishot;
return ret;
