From c492d4c74dd3f87559883ffa0f94a8f1ae3fe5f5 Mon Sep 17 00:00:00 2001 From: Xin Long Date: Thu, 20 Jun 2019 18:39:28 +0800 Subject: tipc: change to use register_pernet_device This patch is to fix a dst defcnt leak, which can be reproduced by doing: # ip net a c; ip net a s; modprobe tipc # ip net e s ip l a n eth1 type veth peer n eth1 netns c # ip net e c ip l s lo up; ip net e c ip l s eth1 up # ip net e s ip l s lo up; ip net e s ip l s eth1 up # ip net e c ip a a 1.1.1.2/8 dev eth1 # ip net e s ip a a 1.1.1.1/8 dev eth1 # ip net e c tipc b e m udp n u1 localip 1.1.1.2 # ip net e s tipc b e m udp n u1 localip 1.1.1.1 # ip net d c; ip net d s; rmmod tipc and it will get stuck and keep logging the error: unregister_netdevice: waiting for lo to become free. Usage count = 1 The cause is that a dst is held by the udp sock's sk_rx_dst set on udp rx path with udp_early_demux == 1, and this dst (eventually holding lo dev) can't be released as bearer's removal in tipc pernet .exit happens after lo dev's removal, default_device pernet .exit. "There are two distinct types of pernet_operations recognized: subsys and device. At creation all subsys init functions are called before device init functions, and at destruction all device exit functions are called before subsys exit function." So by calling register_pernet_device instead to register tipc_net_ops, the pernet .exit() will be invoked earlier than loopback dev's removal when a netns is being destroyed, as fou/gue does. Note that vxlan and geneve udp tunnels don't have this issue, as the udp sock is released in their device ndo_stop(). This fix is also necessary for tipc dst_cache, which will hold dsts on tx path and I will introduce in my next patch. Reported-by: Li Shuang Signed-off-by: Xin Long Acked-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/core.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'net/tipc') diff --git a/net/tipc/core.c b/net/tipc/core.c index ed536c05252a..c8370722f0bb 100644 --- a/net/tipc/core.c +++ b/net/tipc/core.c @@ -134,7 +134,7 @@ static int __init tipc_init(void) if (err) goto out_sysctl; - err = register_pernet_subsys(&tipc_net_ops); + err = register_pernet_device(&tipc_net_ops); if (err) goto out_pernet; @@ -142,7 +142,7 @@ static int __init tipc_init(void) if (err) goto out_socket; - err = register_pernet_subsys(&tipc_topsrv_net_ops); + err = register_pernet_device(&tipc_topsrv_net_ops); if (err) goto out_pernet_topsrv; @@ -153,11 +153,11 @@ static int __init tipc_init(void) pr_info("Started in single node mode\n"); return 0; out_bearer: - unregister_pernet_subsys(&tipc_topsrv_net_ops); + unregister_pernet_device(&tipc_topsrv_net_ops); out_pernet_topsrv: tipc_socket_stop(); out_socket: - unregister_pernet_subsys(&tipc_net_ops); + unregister_pernet_device(&tipc_net_ops); out_pernet: tipc_unregister_sysctl(); out_sysctl: @@ -172,9 +172,9 @@ out_netlink: static void __exit tipc_exit(void) { tipc_bearer_cleanup(); - unregister_pernet_subsys(&tipc_topsrv_net_ops); + unregister_pernet_device(&tipc_topsrv_net_ops); tipc_socket_stop(); - unregister_pernet_subsys(&tipc_net_ops); + unregister_pernet_device(&tipc_net_ops); tipc_netlink_stop(); tipc_netlink_compat_stop(); tipc_unregister_sysctl(); -- cgit v1.2.3-55-g7522 From 4f07b80c973348a99b5d2a32476a2e7877e94a05 Mon Sep 17 00:00:00 2001 From: Xin Long Date: Tue, 25 Jun 2019 00:28:19 +0800 Subject: tipc: check msg->req data len in tipc_nl_compat_bearer_disable This patch is to fix an uninit-value issue, reported by syzbot: BUG: KMSAN: uninit-value in memchr+0xce/0x110 lib/string.c:981 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x191/0x1f0 lib/dump_stack.c:113 kmsan_report+0x130/0x2a0 mm/kmsan/kmsan.c:622 __msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:310 memchr+0xce/0x110 lib/string.c:981 string_is_valid net/tipc/netlink_compat.c:176 [inline] tipc_nl_compat_bearer_disable+0x2a1/0x480 net/tipc/netlink_compat.c:449 __tipc_nl_compat_doit net/tipc/netlink_compat.c:327 [inline] tipc_nl_compat_doit+0x3ac/0xb00 net/tipc/netlink_compat.c:360 tipc_nl_compat_handle net/tipc/netlink_compat.c:1178 [inline] tipc_nl_compat_recv+0x1b1b/0x27b0 net/tipc/netlink_compat.c:1281 TLV_GET_DATA_LEN() may return a negtive int value, which will be used as size_t (becoming a big unsigned long) passed into memchr, cause this issue. Similar to what it does in tipc_nl_compat_bearer_enable(), this fix is to return -EINVAL when TLV_GET_DATA_LEN() is negtive in tipc_nl_compat_bearer_disable(), as well as in tipc_nl_compat_link_stat_dump() and tipc_nl_compat_link_reset_stats(). v1->v2: - add the missing Fixes tags per Eric's request. Fixes: 0762216c0ad2 ("tipc: fix uninit-value in tipc_nl_compat_bearer_enable") Fixes: 8b66fee7f8ee ("tipc: fix uninit-value in tipc_nl_compat_link_reset_stats") Reported-by: syzbot+30eaa8bf392f7fafffaf@syzkaller.appspotmail.com Signed-off-by: Xin Long Signed-off-by: David S. Miller --- net/tipc/netlink_compat.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) (limited to 'net/tipc') diff --git a/net/tipc/netlink_compat.c b/net/tipc/netlink_compat.c index c6a04c09d075..cf155061c472 100644 --- a/net/tipc/netlink_compat.c +++ b/net/tipc/netlink_compat.c @@ -445,7 +445,11 @@ static int tipc_nl_compat_bearer_disable(struct tipc_nl_compat_cmd_doit *cmd, if (!bearer) return -EMSGSIZE; - len = min_t(int, TLV_GET_DATA_LEN(msg->req), TIPC_MAX_BEARER_NAME); + len = TLV_GET_DATA_LEN(msg->req); + if (len <= 0) + return -EINVAL; + + len = min_t(int, len, TIPC_MAX_BEARER_NAME); if (!string_is_valid(name, len)) return -EINVAL; @@ -539,7 +543,11 @@ static int tipc_nl_compat_link_stat_dump(struct tipc_nl_compat_msg *msg, name = (char *)TLV_DATA(msg->req); - len = min_t(int, TLV_GET_DATA_LEN(msg->req), TIPC_MAX_LINK_NAME); + len = TLV_GET_DATA_LEN(msg->req); + if (len <= 0) + return -EINVAL; + + len = min_t(int, len, TIPC_MAX_BEARER_NAME); if (!string_is_valid(name, len)) return -EINVAL; @@ -817,7 +825,11 @@ static int tipc_nl_compat_link_reset_stats(struct tipc_nl_compat_cmd_doit *cmd, if (!link) return -EMSGSIZE; - len = min_t(int, TLV_GET_DATA_LEN(msg->req), TIPC_MAX_LINK_NAME); + len = TLV_GET_DATA_LEN(msg->req); + if (len <= 0) + return -EINVAL; + + len = min_t(int, len, TIPC_MAX_BEARER_NAME); if (!string_is_valid(name, len)) return -EINVAL; -- cgit v1.2.3-55-g7522