This is a note to let you know that I've just added the patch titled
io_uring/rw: fix unexpected link breakage
to the 5.15-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-rw-fix-unexpected-link-breakage.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Mon Oct 17 11:43:27 AM CEST 2022
From: Pavel Begunkov <asml.silence@xxxxxxxxx>
Date: Sun, 16 Oct 2022 22:42:58 +0100
Subject: io_uring/rw: fix unexpected link breakage
To: stable@xxxxxxxxxxxxxxx
Cc: Jens Axboe <axboe@xxxxxxxxx>, asml.silence@xxxxxxxxx
Message-ID: <1b05243cdfa8135866a6ccc115e491df8d725d16.1665954636.git.asml.silence@xxxxxxxxx>
From: Pavel Begunkov <asml.silence@xxxxxxxxx>
[ upstream commit bf68b5b34311ee57ed40749a1257a30b46127556 ]
req->cqe.res is set in io_read() to the amount of bytes left to be done,
which is used to figure out whether to fail a read or not. However,
io_read() may do another without returning, and we stash the previous
value into ->bytes_done but forget to update cqe.res. Then we ask a read
to do strictly less than cqe.res but expect the return to be exactly
cqe.res.
Fix the bug by updating cqe.res for retries.
Cc: stable@xxxxxxxxxxxxxxx
Reported-and-Tested-by: Beld Zhang <beldzhang@xxxxxxxxx>
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Link: https://lore.kernel.org/r/3a1088440c7be98e5800267af922a67da0ef9f13.1664235732.git.asml.silence@xxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/io_uring.c | 1 +
1 file changed, 1 insertion(+)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -3606,6 +3606,7 @@ static int io_read(struct io_kiocb *req,
return -EAGAIN;
}
+ req->result = iov_iter_count(iter);
/*
* Now retry read with the IOCB_WAITQ parts set in the iocb. If
* we get -EIOCBQUEUED, then we'll get a notification when the
Patches currently in stable-queue which might be from asml.silence@xxxxxxxxx are
queue-5.15/io_uring-correct-pinned_vm-accounting.patch
queue-5.15/io_uring-net-don-t-update-msg_name-if-not-provided.patch
queue-5.15/io_uring-rw-fix-unexpected-link-breakage.patch
queue-5.15/io_uring-rw-fix-error-ed-retry-return-values.patch
queue-5.15/io_uring-rw-fix-short-rw-error-handling.patch
queue-5.15/io_uring-af_unix-defer-registered-files-gc-to-io_uring-release.patch
