From: Jens Axboe <axboe@kernel.dk>
Date: Sun, 17 Apr 2022 03:14:00 +0000 (-0600)
Subject: io_uring: free iovec if file assignment fails
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=323b190ba2debbcc03c01d2edaf1ec6b43e6ae43;p=linux.git

io_uring: free iovec if file assignment fails

We just return failure in this case, but we need to release the iovec
first. If we're doing IO with more than FAST_IOV segments, then the
iovec is allocated and must be freed.

Reported-by: syzbot+96b43810dfe9c3bb95ed@syzkaller.appspotmail.com
Fixes: 584b0180f0f4 ("io_uring: move read/write file prep state into actual opcode handler")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 4479013854d20..24409dd072393 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -3832,8 +3832,10 @@ static int io_read(struct io_kiocb *req, unsigned int issue_flags)
 		iovec = NULL;
 	}
 	ret = io_rw_init_file(req, FMODE_READ);
-	if (unlikely(ret))
+	if (unlikely(ret)) {
+		kfree(iovec);
 		return ret;
+	}
 	req->result = iov_iter_count(&s->iter);
 
 	if (force_nonblock) {
@@ -3958,8 +3960,10 @@ static int io_write(struct io_kiocb *req, unsigned int issue_flags)
 		iovec = NULL;
 	}
 	ret = io_rw_init_file(req, FMODE_WRITE);
-	if (unlikely(ret))
+	if (unlikely(ret)) {
+		kfree(iovec);
 		return ret;
+	}
 	req->result = iov_iter_count(&s->iter);
 
 	if (force_nonblock) {