[PATCH] io_uring/rw: ensure allocated iovec gets cleared for early failure

[PATCH] io_uring/rw: ensure allocated iovec gets cleared for early failure

[Jens Axboe]

A previous commit reused the recyling infrastructure for early cleanup,
but this is not enough for the case where our internal caches have
overflowed. If this happens, then the allocated iovec can get leaked if
the request is also aborted early.

Reinstate the previous forced free of the iovec for that situation.

Cc: stable@vger.kernel.org
Reported-by: syzbot+3c93637d7648c24e1fd0@syzkaller.appspotmail.com
Fixes: 9ac273ae3dc2 ("io_uring/rw: use io_rw_recycle() from cleanup path")
Link: https://lore.kernel.org/io-uring/69122a59.a70a0220.22f260.00fd.GAE@google.com/
Signed-off-by: Jens Axboe <axboe@kernel.dk>

---

diff --git a/io_uring/rw.c b/io_uring/rw.c
index 5b2241a5813c..abe68ba9c9dc 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -463,7 +463,10 @@ int io_read_mshot_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 
 void io_readv_writev_cleanup(struct io_kiocb *req)
 {
+	struct io_async_rw *rw = req->async_data;
+
 	lockdep_assert_held(&req->ctx->uring_lock);
+	io_vec_free(&rw->vec);
 	io_rw_recycle(req, 0);
 }
 
-- 
Jens Axboe