On 3/2/20 11:13 AM, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
>
> The patch below does not apply to the 5.4-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@xxxxxxxxxxxxxxx>.
Here's a 5.4 version.
commit d876836204897b6d7d911f942084f69a1e9d5c4d
Author: Jens Axboe <axboe@xxxxxxxxx>
Date: Thu Feb 27 14:17:49 2020 -0700
io_uring: fix 32-bit compatability with sendmsg/recvmsg
We must set MSG_CMSG_COMPAT if we're in compatability mode, otherwise
the iovec import for these commands will not do the right thing and fail
the command with -EINVAL.
Found by running the test suite compiled as 32-bit.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: aa1fa28fc73e ("io_uring: add support for recvmsg()")
Fixes: 0fa03c624d8f ("io_uring: add support for sendmsg()")
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 607edaef5e71..4e7504eeb015 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1666,6 +1666,11 @@ static int io_send_recvmsg(struct io_kiocb *req, const struct io_uring_sqe *sqe,
else if (force_nonblock)
flags |= MSG_DONTWAIT;
+#ifdef CONFIG_COMPAT
+ if (req->ctx->compat)
+ flags |= MSG_CMSG_COMPAT;
+#endif
+
msg = (struct user_msghdr __user *) (unsigned long)
READ_ONCE(sqe->addr);
--
Jens Axboe
