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authorXin Long <lucien.xin@gmail.com>2019-09-03 17:53:12 +0800
committerDavid S. Miller <davem@davemloft.net>2019-09-05 09:58:49 +0200
commit42dec1dbe38239cf91cc1f4df7830c66276ced37 (patch)
tree0e207bea0f6a801caddbc98e40f8df83ed729c00 /net/tipc
parent6a87691c40ecaf0dc3f5902ad138039c91083d50 (diff)
tipc: add NULL pointer check before calling kfree_rcu
Unlike kfree(p), kfree_rcu(p, rcu) won't do NULL pointer check. When tipc_nametbl_remove_publ returns NULL, the panic below happens: BUG: unable to handle kernel NULL pointer dereference at 0000000000000068 RIP: 0010:__call_rcu+0x1d/0x290 Call Trace: <IRQ> tipc_publ_notify+0xa9/0x170 [tipc] tipc_node_write_unlock+0x8d/0x100 [tipc] tipc_node_link_down+0xae/0x1d0 [tipc] tipc_node_check_dest+0x3ea/0x8f0 [tipc] ? tipc_disc_rcv+0x2c7/0x430 [tipc] tipc_disc_rcv+0x2c7/0x430 [tipc] ? tipc_rcv+0x6bb/0xf20 [tipc] tipc_rcv+0x6bb/0xf20 [tipc] ? ip_route_input_slow+0x9cf/0xb10 tipc_udp_recv+0x195/0x1e0 [tipc] ? tipc_udp_is_known_peer+0x80/0x80 [tipc] udp_queue_rcv_skb+0x180/0x460 udp_unicast_rcv_skb.isra.56+0x75/0x90 __udp4_lib_rcv+0x4ce/0xb90 ip_local_deliver_finish+0x11c/0x210 ip_local_deliver+0x6b/0xe0 ? ip_rcv_finish+0xa9/0x410 ip_rcv+0x273/0x362 Fixes: 97ede29e80ee ("tipc: convert name table read-write lock to RCU") Reported-by: Li Shuang <shuali@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/tipc')
-rw-r--r--net/tipc/name_distr.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/net/tipc/name_distr.c b/net/tipc/name_distr.c
index 44abc8e9c990..241ed2274473 100644
--- a/net/tipc/name_distr.c
+++ b/net/tipc/name_distr.c
@@ -223,7 +223,8 @@ static void tipc_publ_purge(struct net *net, struct publication *publ, u32 addr)
publ->key);
}
- kfree_rcu(p, rcu);
+ if (p)
+ kfree_rcu(p, rcu);
}
/**