io_uring/net: check socket is valid in io_bind()/io_listen()

We need to check that sock_from_file(req->file) != NULL.

Reported-by: syzbot <syzbot+1e811482aa2c70afa9a0@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=1e811482aa2c70afa9a0
Fixes: 7481fd93fa0a ("io_uring: Introduce IORING_OP_BIND")
Fixes: ff140cc8628a ("io_uring: Introduce IORING_OP_LISTEN")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Link: https://lore.kernel.org/r/903da529-eaa3-43ef-ae41-d30f376c60cc@I-love.SAKURA.ne.jp
[axboe: move assignment of sock to where the NULL check is]
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/io_uring/net.c b/io_uring/net.c
index 25223e11958f8c2b15baf9843af82f1d60856bfe..7ebbeab05fea733d64564a8da325a900c70e3635 100644 (file)
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -1747,9 +1747,14 @@ int io_bind(struct io_kiocb *req, unsigned int issue_flags)
 {
        struct io_bind *bind = io_kiocb_to_cmd(req, struct io_bind);
        struct io_async_msghdr *io = req->async_data;
+       struct socket *sock;
        int ret;
 
-       ret = __sys_bind_socket(sock_from_file(req->file),  &io->addr, bind->addr_len);
+       sock = sock_from_file(req->file);
+       if (unlikely(!sock))
+               return -ENOTSOCK;
+
+       ret = __sys_bind_socket(sock, &io->addr, bind->addr_len);
        if (ret < 0)
                req_set_fail(req);
        io_req_set_res(req, ret, 0);
@@ -1770,9 +1775,14 @@ int io_listen_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 int io_listen(struct io_kiocb *req, unsigned int issue_flags)
 {
        struct io_listen *listen = io_kiocb_to_cmd(req, struct io_listen);
+       struct socket *sock;
        int ret;
 
-       ret = __sys_listen_socket(sock_from_file(req->file), listen->backlog);
+       sock = sock_from_file(req->file);
+       if (unlikely(!sock))
+               return -ENOTSOCK;
+
+       ret = __sys_listen_socket(sock, listen->backlog);
        if (ret < 0)
                req_set_fail(req);
        io_req_set_res(req, ret, 0);