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| author | Jens Axboe <axboe@kernel.dk> | 2023-06-23 07:38:14 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-06-28 10:29:44 +0200 |
| commit | 34a7e5021a437bf813e1b52fc9043b43d48e2325 (patch) | |
| tree | 613b888184ad4016160554b22cf3eed527bd2df2 /io_uring | |
| parent | b07bb2914adac63d9a10c2878d4a0a0edf27edfe (diff) | |
| download | linux-34a7e5021a437bf813e1b52fc9043b43d48e2325.tar.gz linux-34a7e5021a437bf813e1b52fc9043b43d48e2325.tar.bz2 linux-34a7e5021a437bf813e1b52fc9043b43d48e2325.zip | |
io_uring/net: save msghdr->msg_control for retries
Commit cac9e4418f4cbd548ccb065b3adcafe073f7f7d2 upstream.
If the application sets ->msg_control and we have to later retry this
command, or if it got queued with IOSQE_ASYNC to begin with, then we
need to retain the original msg_control value. This is due to the net
stack overwriting this field with an in-kernel pointer, to copy it
in. Hitting that path for the second time will now fail the copy from
user, as it's attempting to copy from a non-user address.
Cc: stable@vger.kernel.org # 5.10+
Link: https://github.com/axboe/liburing/issues/880
Reported-and-tested-by: Marek Majkowski <marek@cloudflare.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'io_uring')
| -rw-r--r-- | io_uring/io_uring.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 1d8adc57a44a..f7c41d3d7752 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -581,6 +581,7 @@ struct io_sr_msg { size_t len; size_t done_io; struct io_buffer *kbuf; + void __user *msg_control; }; struct io_open { @@ -4864,10 +4865,16 @@ static int io_setup_async_msg(struct io_kiocb *req, static int io_sendmsg_copy_hdr(struct io_kiocb *req, struct io_async_msghdr *iomsg) { + struct io_sr_msg *sr = &req->sr_msg; + int ret; + iomsg->msg.msg_name = &iomsg->addr; iomsg->free_iov = iomsg->fast_iov; - return sendmsg_copy_msghdr(&iomsg->msg, req->sr_msg.umsg, + ret = sendmsg_copy_msghdr(&iomsg->msg, req->sr_msg.umsg, req->sr_msg.msg_flags, &iomsg->free_iov); + /* save msg_control as sys_sendmsg() overwrites it */ + sr->msg_control = iomsg->msg.msg_control; + return ret; } static int io_sendmsg_prep_async(struct io_kiocb *req) @@ -4924,6 +4931,8 @@ static int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags) if (ret) return ret; kmsg = &iomsg; + } else { + kmsg->msg.msg_control = sr->msg_control; } flags = req->sr_msg.msg_flags; |