diff options
| author | Xin Long <lucien.xin@gmail.com> | 2021-07-23 13:25:36 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-07-25 10:43:30 +0100 |
| commit | cc19862ffe454a5b632ca202e5a51bfec9f89fd2 (patch) | |
| tree | 0ad35c689e8a5ba8ff969e53894711e50e3e5aa9 /net | |
| parent | 0e804326759de7b9991353dd66b03595b5c3f544 (diff) | |
tipc: fix an use-after-free issue in tipc_recvmsg
syzbot reported an use-after-free crash:
BUG: KASAN: use-after-free in tipc_recvmsg+0xf77/0xf90 net/tipc/socket.c:1979
Call Trace:
tipc_recvmsg+0xf77/0xf90 net/tipc/socket.c:1979
sock_recvmsg_nosec net/socket.c:943 [inline]
sock_recvmsg net/socket.c:961 [inline]
sock_recvmsg+0xca/0x110 net/socket.c:957
tipc_conn_rcv_from_sock+0x162/0x2f0 net/tipc/topsrv.c:398
tipc_conn_recv_work+0xeb/0x190 net/tipc/topsrv.c:421
process_one_work+0x98d/0x1630 kernel/workqueue.c:2276
worker_thread+0x658/0x11f0 kernel/workqueue.c:2422
As Hoang pointed out, it was caused by skb_cb->bytes_read still accessed
after calling tsk_advance_rx_queue() to free the skb in tipc_recvmsg().
This patch is to fix it by accessing skb_cb->bytes_read earlier than
calling tsk_advance_rx_queue().
Fixes: f4919ff59c28 ("tipc: keep the skb in rcv queue until the whole data is read")
Reported-by: syzbot+e6741b97d5552f97c24d@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/tipc/socket.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 9b0b311c7ec1..b0dd183a4dbc 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -1973,10 +1973,12 @@ static int tipc_recvmsg(struct socket *sock, struct msghdr *m, tipc_node_distr_xmit(sock_net(sk), &xmitq); } - if (!skb_cb->bytes_read) - tsk_advance_rx_queue(sk); + if (skb_cb->bytes_read) + goto exit; + + tsk_advance_rx_queue(sk); - if (likely(!connected) || skb_cb->bytes_read) + if (likely(!connected)) goto exit; /* Send connection flow control advertisement when applicable */ |