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![]() l2tp_tunnel_register() registers a tunnel without fully initializing its attribute. This can allow another kernel thread running l2tp_xmit_core() to access the uninitialized data and then cause a kernel NULL pointer dereference error, as shown below. Thread 1 Thread 2 //l2tp_tunnel_register() list_add_rcu(&tunnel->list, &pn->l2tp_tunnel_list); //pppol2tp_connect() tunnel = l2tp_tunnel_get(sock_net(sk), info.tunnel_id); // Fetch the new tunnel ... //l2tp_xmit_core() struct sock *sk = tunnel->sock; ... bh_lock_sock(sk); //Null pointer error happens tunnel->sock = sk; Fix this bug by initializing tunnel->sock before adding the tunnel into l2tp_tunnel_list. Reviewed-by: Cong Wang <cong.wang@bytedance.com> Signed-off-by: Sishuai Gong <sishuai@purdue.edu> Reported-by: Sishuai Gong <sishuai@purdue.edu> Signed-off-by: David S. Miller <davem@davemloft.net> |
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.. | ||
Kconfig | ||
l2tp_core.c | ||
l2tp_core.h | ||
l2tp_debugfs.c | ||
l2tp_eth.c | ||
l2tp_ip.c | ||
l2tp_ip6.c | ||
l2tp_netlink.c | ||
l2tp_ppp.c | ||
Makefile | ||
trace.h |