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2023-01-18tipc: call tipc_lxc_xmit without holding node_read_lockXin Long
commit 88956177db179e4eba7cd590971961857d1565b8 upstream. When sending packets between nodes in netns, it calls tipc_lxc_xmit() for peer node to receive the packets where tipc_sk_mcast_rcv()/tipc_sk_rcv() might be called, and it's pretty much like in tipc_rcv(). Currently the local 'node rw lock' is held during calling tipc_lxc_xmit() to protect the peer_net not being freed by another thread. However, when receiving these packets, tipc_node_add_conn() might be called where the peer 'node rw lock' is acquired. Then a dead lock warning is triggered by lockdep detector, although it is not a real dead lock: WARNING: possible recursive locking detected -------------------------------------------- conn_server/1086 is trying to acquire lock: ffff8880065cb020 (&n->lock#2){++--}-{2:2}, \ at: tipc_node_add_conn.cold.76+0xaa/0x211 [tipc] but task is already holding lock: ffff8880065cd020 (&n->lock#2){++--}-{2:2}, \ at: tipc_node_xmit+0x285/0xb30 [tipc] other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&n->lock#2); lock(&n->lock#2); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by conn_server/1086: #0: ffff8880036d1e40 (sk_lock-AF_TIPC){+.+.}-{0:0}, \ at: tipc_accept+0x9c0/0x10b0 [tipc] #1: ffff8880036d5f80 (sk_lock-AF_TIPC/1){+.+.}-{0:0}, \ at: tipc_accept+0x363/0x10b0 [tipc] #2: ffff8880065cd020 (&n->lock#2){++--}-{2:2}, \ at: tipc_node_xmit+0x285/0xb30 [tipc] #3: ffff888012e13370 (slock-AF_TIPC){+...}-{2:2}, \ at: tipc_sk_rcv+0x2da/0x1b40 [tipc] Call Trace: <TASK> dump_stack_lvl+0x44/0x5b __lock_acquire.cold.77+0x1f2/0x3d7 lock_acquire+0x1d2/0x610 _raw_write_lock_bh+0x38/0x80 tipc_node_add_conn.cold.76+0xaa/0x211 [tipc] tipc_sk_finish_conn+0x21e/0x640 [tipc] tipc_sk_filter_rcv+0x147b/0x3030 [tipc] tipc_sk_rcv+0xbb4/0x1b40 [tipc] tipc_lxc_xmit+0x225/0x26b [tipc] tipc_node_xmit.cold.82+0x4a/0x102 [tipc] __tipc_sendstream+0x879/0xff0 [tipc] tipc_accept+0x966/0x10b0 [tipc] do_accept+0x37d/0x590 This patch avoids this warning by not holding the 'node rw lock' before calling tipc_lxc_xmit(). As to protect the 'peer_net', rcu_read_lock() should be enough, as in cleanup_net() when freeing the netns, it calls synchronize_rcu() before the free is continued. Also since tipc_lxc_xmit() is like the RX path in tipc_rcv(), it makes sense to call it under rcu_read_lock(). Note that the right lock order must be: rcu_read_lock(); tipc_node_read_lock(n); tipc_node_read_unlock(n); tipc_lxc_xmit(); rcu_read_unlock(); instead of: tipc_node_read_lock(n); rcu_read_lock(); tipc_node_read_unlock(n); tipc_lxc_xmit(); rcu_read_unlock(); and we have to call tipc_node_read_lock/unlock() twice in tipc_node_xmit(). Fixes: f73b12812a3d ("tipc: improve throughput between nodes in netns") Reported-by: Shuang Li <shuali@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Link: https://lore.kernel.org/r/5bdd1f8fee9db695cfff4528a48c9b9d0523fb00.1670110641.git.lucien.xin@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-18tipc: Add a missing case of TIPC_DIRECT_MSG typeHoang Le
commit 8b1e5b0a99f04bda2d6c85ecfe5e68a356c10914 upstream. In the commit f73b12812a3d ("tipc: improve throughput between nodes in netns"), we're missing a check to handle TIPC_DIRECT_MSG type, it's still using old sending mechanism for this message type. So, throughput improvement is not significant as expected. Besides that, when sending a large message with that type, we're also handle wrong receiving queue, it should be enqueued in socket receiving instead of multicast messages. Fix this by adding the missing case for TIPC_DIRECT_MSG. Fixes: f73b12812a3d ("tipc: improve throughput between nodes in netns") Reported-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au> Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-18tipc: fix use-after-free in tipc_disc_rcv()Tuong Lien
commit 31e4ccc99eda8a5a7e6902c98bee6e78ffd3edb9 upstream. In the function 'tipc_disc_rcv()', the 'msg_peer_net_hash()' is called to read the header data field but after the message skb has been freed, that might result in a garbage value... This commit fixes it by defining a new local variable to store the data first, just like the other header fields' handling. Fixes: f73b12812a3d ("tipc: improve throughput between nodes in netns") Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-18tipc: fix unexpected link reset due to discovery messagesTung Nguyen
[ Upstream commit c244c092f1ed2acfb5af3d3da81e22367d3dd733 ] This unexpected behavior is observed: node 1 | node 2 ------ | ------ link is established | link is established reboot | link is reset up | send discovery message receive discovery message | link is established | link is established send discovery message | | receive discovery message | link is reset (unexpected) | send reset message link is reset | It is due to delayed re-discovery as described in function tipc_node_check_dest(): "this link endpoint has already reset and re-established contact with the peer, before receiving a discovery message from that node." However, commit 598411d70f85 has changed the condition for calling tipc_node_link_down() which was the acceptance of new media address. This commit fixes this by restoring the old and correct behavior. Fixes: 598411d70f85 ("tipc: make resetting of links non-atomic") Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: Tung Nguyen <tung.q.nguyen@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-18tipc: eliminate checking netns if node establishedHoang Le
[ Upstream commit d408bef4bfa60bac665b6e7239269570039a968b ] Currently, we scan over all network namespaces at each received discovery message in order to check if the sending peer might be present in a host local namespaces. This is unnecessary since we can assume that a peer will not change its location during an established session. We now improve the condition for this testing so that we don't perform any redundant scans. Fixes: f73b12812a3d ("tipc: improve throughput between nodes in netns") Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net> Stable-dep-of: c244c092f1ed ("tipc: fix unexpected link reset due to discovery messages") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-18tipc: improve throughput between nodes in netnsHoang Le
[ Upstream commit f73b12812a3d1d798b7517547ccdcf864844d2cd ] Currently, TIPC transports intra-node user data messages directly socket to socket, hence shortcutting all the lower layers of the communication stack. This gives TIPC very good intra node performance, both regarding throughput and latency. We now introduce a similar mechanism for TIPC data traffic across network namespaces located in the same kernel. On the send path, the call chain is as always accompanied by the sending node's network name space pointer. However, once we have reliably established that the receiving node is represented by a namespace on the same host, we just replace the namespace pointer with the receiving node/namespace's ditto, and follow the regular socket receive patch though the receiving node. This technique gives us a throughput similar to the node internal throughput, several times larger than if we let the traffic go though the full network stacks. As a comparison, max throughput for 64k messages is four times larger than TCP throughput for the same type of traffic. To meet any security concerns, the following should be noted. - All nodes joining a cluster are supposed to have been be certified and authenticated by mechanisms outside TIPC. This is no different for nodes/namespaces on the same host; they have to auto discover each other using the attached interfaces, and establish links which are supervised via the regular link monitoring mechanism. Hence, a kernel local node has no other way to join a cluster than any other node, and have to obey to policies set in the IP or device layers of the stack. - Only when a sender has established with 100% certainty that the peer node is located in a kernel local namespace does it choose to let user data messages, and only those, take the crossover path to the receiving node/namespace. - If the receiving node/namespace is removed, its namespace pointer is invalidated at all peer nodes, and their neighbor link monitoring will eventually note that this node is gone. - To ensure the "100% certainty" criteria, and prevent any possible spoofing, received discovery messages must contain a proof that the sender knows a common secret. We use the hash mix of the sending node/namespace for this purpose, since it can be accessed directly by all other namespaces in the kernel. Upon reception of a discovery message, the receiver checks this proof against all the local namespaces'hash_mix:es. If it finds a match, that, along with a matching node id and cluster id, this is deemed sufficient proof that the peer node in question is in a local namespace, and a wormhole can be opened. - We should also consider that TIPC is intended to be a cluster local IPC mechanism (just like e.g. UNIX sockets) rather than a network protocol, and hence we think it can justified to allow it to shortcut the lower protocol layers. Regarding traceability, we should notice that since commit 6c9081a3915d ("tipc: add loopback device tracking") it is possible to follow the node internal packet flow by just activating tcpdump on the loopback interface. This will be true even for this mechanism; by activating tcpdump on the involved nodes' loopback interfaces their inter-name space messaging can easily be tracked. v2: - update 'net' pointer when node left/rejoined v3: - grab read/write lock when using node ref obj v4: - clone traffics between netns to loopback Suggested-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net> Stable-dep-of: c244c092f1ed ("tipc: fix unexpected link reset due to discovery messages") Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-14tipc: Fix potential OOB in tipc_link_proto_rcv()YueHaibing
[ Upstream commit 743117a997bbd4840e827295c07e59bcd7f7caa3 ] Fix the potential risk of OOB if skb_linearize() fails in tipc_link_proto_rcv(). Fixes: 5cbb28a4bf65 ("tipc: linearize arriving NAME_DISTR and LINK_PROTO buffers") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Link: https://lore.kernel.org/r/20221203094635.29024-1-yuehaibing@huawei.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-08tipc: check skb_linearize() return value in tipc_disc_rcv()YueHaibing
[ Upstream commit cd0f6421162201e4b22ce757a1966729323185eb ] If skb_linearize() fails in tipc_disc_rcv(), we need to free the skb instead of handle it. Fixes: 25b0b9c4e835 ("tipc: handle collisions of 32-bit node address hash values") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Acked-by: Jon Maloy <jmaloy@redhat.com> Link: https://lore.kernel.org/r/20221119072832.7896-1-yuehaibing@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-08tipc: add an extra conn_get in tipc_conn_allocXin Long
[ Upstream commit a7b42969d63f47320853a802efd879fbdc4e010e ] One extra conn_get() is needed in tipc_conn_alloc(), as after tipc_conn_alloc() is called, tipc_conn_close() may free this con before deferencing it in tipc_topsrv_accept(): tipc_conn_alloc(); newsk = newsock->sk; <---- tipc_conn_close(); write_lock_bh(&sk->sk_callback_lock); newsk->sk_data_ready = tipc_conn_data_ready; Then an uaf issue can be triggered: BUG: KASAN: use-after-free in tipc_topsrv_accept+0x1e7/0x370 [tipc] Call Trace: <TASK> dump_stack_lvl+0x33/0x46 print_report+0x178/0x4b0 kasan_report+0x8c/0x100 kasan_check_range+0x179/0x1e0 tipc_topsrv_accept+0x1e7/0x370 [tipc] process_one_work+0x6a3/0x1030 worker_thread+0x8a/0xdf0 This patch fixes it by holding it in tipc_conn_alloc(), then after all accessing in tipc_topsrv_accept() releasing it. Note when does this in tipc_topsrv_kern_subscr(), as tipc_conn_rcv_sub() returns 0 or -1 only, we don't need to check for "> 0". Fixes: c5fa7b3cf3cb ("tipc: introduce new TIPC server infrastructure") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-08tipc: set con sock in tipc_conn_allocXin Long
[ Upstream commit 0e5d56c64afcd6fd2d132ea972605b66f8a7d3c4 ] A crash was reported by Wei Chen: BUG: kernel NULL pointer dereference, address: 0000000000000018 RIP: 0010:tipc_conn_close+0x12/0x100 Call Trace: tipc_topsrv_exit_net+0x139/0x320 ops_exit_list.isra.9+0x49/0x80 cleanup_net+0x31a/0x540 process_one_work+0x3fa/0x9f0 worker_thread+0x42/0x5c0 It was caused by !con->sock in tipc_conn_close(). In tipc_topsrv_accept(), con is allocated in conn_idr then its sock is set: con = tipc_conn_alloc(); ... <----[1] con->sock = newsock; If tipc_conn_close() is called in anytime of [1], the null-pointer-def is triggered by con->sock->sk due to con->sock is not yet set. This patch fixes it by moving the con->sock setting to tipc_conn_alloc() under s->idr_lock. So that con->sock can never be NULL when getting the con from s->conn_idr. It will be also safer to move con->server and flag CF_CONNECTED setting under s->idr_lock, as they should all be set before tipc_conn_alloc() is called. Fixes: c5fa7b3cf3cb ("tipc: introduce new TIPC server infrastructure") Reported-by: Wei Chen <harperchen1110@gmail.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-25tipc: fix the msg->req tlv len check in tipc_nl_compat_name_table_dump_headerXin Long
[ Upstream commit 1c075b192fe41030457cd4a5f7dea730412bca40 ] This is a follow-up for commit 974cb0e3e7c9 ("tipc: fix uninit-value in tipc_nl_compat_name_table_dump") where it should have type casted sizeof(..) to int to work when TLV_GET_DATA_LEN() returns a negative value. syzbot reported a call trace because of it: BUG: KMSAN: uninit-value in ... tipc_nl_compat_name_table_dump+0x841/0xea0 net/tipc/netlink_compat.c:934 __tipc_nl_compat_dumpit+0xab2/0x1320 net/tipc/netlink_compat.c:238 tipc_nl_compat_dumpit+0x991/0xb50 net/tipc/netlink_compat.c:321 tipc_nl_compat_recv+0xb6e/0x1640 net/tipc/netlink_compat.c:1324 genl_family_rcv_msg_doit net/netlink/genetlink.c:731 [inline] genl_family_rcv_msg net/netlink/genetlink.c:775 [inline] genl_rcv_msg+0x103f/0x1260 net/netlink/genetlink.c:792 netlink_rcv_skb+0x3a5/0x6c0 net/netlink/af_netlink.c:2501 genl_rcv+0x3c/0x50 net/netlink/genetlink.c:803 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0xf3b/0x1270 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x1288/0x1440 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg net/socket.c:734 [inline] Reported-by: syzbot+e5dbaaa238680ce206ea@syzkaller.appspotmail.com Fixes: 974cb0e3e7c9 ("tipc: fix uninit-value in tipc_nl_compat_name_table_dump") Signed-off-by: Xin Long <lucien.xin@gmail.com> Link: https://lore.kernel.org/r/ccd6a7ea801b15aec092c3b532a883b4c5708695.1667594933.git.lucien.xin@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-03tipc: fix a null-ptr-deref in tipc_topsrv_acceptXin Long
[ Upstream commit 82cb4e4612c633a9ce320e1773114875604a3cce ] syzbot found a crash in tipc_topsrv_accept: KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] Workqueue: tipc_rcv tipc_topsrv_accept RIP: 0010:kernel_accept+0x22d/0x350 net/socket.c:3487 Call Trace: <TASK> tipc_topsrv_accept+0x197/0x280 net/tipc/topsrv.c:460 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 It was caused by srv->listener that might be set to null by tipc_topsrv_stop() in net .exit whereas it's still used in tipc_topsrv_accept() worker. srv->listener is protected by srv->idr_lock in tipc_topsrv_stop(), so add a check for srv->listener under srv->idr_lock in tipc_topsrv_accept() to avoid the null-ptr-deref. To ensure the lsock is not released during the tipc_topsrv_accept(), move sock_release() after tipc_topsrv_work_stop() where it's waiting until the tipc_topsrv_accept worker to be done. Note that sk_callback_lock is used to protect sk->sk_user_data instead of srv->listener, and it should check srv in tipc_topsrv_listener_data_ready() instead. This also ensures that no more tipc_topsrv_accept worker will be started after tipc_conn_close() is called in tipc_topsrv_stop() where it sets sk->sk_user_data to null. Fixes: 0ef897be12b8 ("tipc: separate topology server listener socket from subcsriber sockets") Reported-by: syzbot+c5ce866a8d30f4be0651@syzkaller.appspotmail.com Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Jon Maloy <jmaloy@redhat.com> Link: https://lore.kernel.org/r/4eee264380c409c61c6451af1059b7fb271a7e7b.1666120790.git.lucien.xin@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-29tipc: fix an information leak in tipc_topsrv_kern_subscrAlexander Potapenko
[ Upstream commit 777ecaabd614d47c482a5c9031579e66da13989a ] Use a 8-byte write to initialize sub.usr_handle in tipc_topsrv_kern_subscr(), otherwise four bytes remain uninitialized when issuing setsockopt(..., SOL_TIPC, ...). This resulted in an infoleak reported by KMSAN when the packet was received: ===================================================== BUG: KMSAN: kernel-infoleak in copyout+0xbc/0x100 lib/iov_iter.c:169 instrument_copy_to_user ./include/linux/instrumented.h:121 copyout+0xbc/0x100 lib/iov_iter.c:169 _copy_to_iter+0x5c0/0x20a0 lib/iov_iter.c:527 copy_to_iter ./include/linux/uio.h:176 simple_copy_to_iter+0x64/0xa0 net/core/datagram.c:513 __skb_datagram_iter+0x123/0xdc0 net/core/datagram.c:419 skb_copy_datagram_iter+0x58/0x200 net/core/datagram.c:527 skb_copy_datagram_msg ./include/linux/skbuff.h:3903 packet_recvmsg+0x521/0x1e70 net/packet/af_packet.c:3469 ____sys_recvmsg+0x2c4/0x810 net/socket.c:? ___sys_recvmsg+0x217/0x840 net/socket.c:2743 __sys_recvmsg net/socket.c:2773 __do_sys_recvmsg net/socket.c:2783 __se_sys_recvmsg net/socket.c:2780 __x64_sys_recvmsg+0x364/0x540 net/socket.c:2780 do_syscall_x64 arch/x86/entry/common.c:50 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd arch/x86/entry/entry_64.S:120 ... Uninit was stored to memory at: tipc_sub_subscribe+0x42d/0xb50 net/tipc/subscr.c:156 tipc_conn_rcv_sub+0x246/0x620 net/tipc/topsrv.c:375 tipc_topsrv_kern_subscr+0x2e8/0x400 net/tipc/topsrv.c:579 tipc_group_create+0x4e7/0x7d0 net/tipc/group.c:190 tipc_sk_join+0x2a8/0x770 net/tipc/socket.c:3084 tipc_setsockopt+0xae5/0xe40 net/tipc/socket.c:3201 __sys_setsockopt+0x87f/0xdc0 net/socket.c:2252 __do_sys_setsockopt net/socket.c:2263 __se_sys_setsockopt net/socket.c:2260 __x64_sys_setsockopt+0xe0/0x160 net/socket.c:2260 do_syscall_x64 arch/x86/entry/common.c:50 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd arch/x86/entry/entry_64.S:120 Local variable sub created at: tipc_topsrv_kern_subscr+0x57/0x400 net/tipc/topsrv.c:562 tipc_group_create+0x4e7/0x7d0 net/tipc/group.c:190 Bytes 84-87 of 88 are uninitialized Memory access of size 88 starts at ffff88801ed57cd0 Data copied to user address 0000000020000400 ... ===================================================== Signed-off-by: Alexander Potapenko <glider@google.com> Fixes: 026321c6d056a5 ("tipc: rename tipc_server to tipc_topsrv") Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-29tipc: Fix recognition of trial periodMark Tomlinson
[ Upstream commit 28be7ca4fcfd69a2d52aaa331adbf9dbe91f9e6e ] The trial period exists until jiffies is after addr_trial_end. But as jiffies will eventually overflow, just using time_after will eventually give incorrect results. As the node address is set once the trial period ends, this can be used to know that we are not in the trial period. Fixes: e415577f57f4 ("tipc: correct discovery message handling during address trial period") Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-15tipc: fix shift wrapping bug in map_get()Dan Carpenter
[ Upstream commit e2b224abd9bf45dcb55750479fc35970725a430b ] There is a shift wrapping bug in this code so anything thing above 31 will return false. Fixes: 35c55c9877f8 ("tipc: add neighbor monitoring framework") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-07-21net: tipc: fix possible refcount leak in tipc_sk_create()Hangyu Hua
[ Upstream commit 00aff3590fc0a73bddd3b743863c14e76fd35c0c ] Free sk in case tipc_sk_insert() fails. Signed-off-by: Hangyu Hua <hbh25y@gmail.com> Reviewed-by: Tung Nguyen <tung.q.nguyen@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14tipc: check attribute length for bearer nameHoang Le
[ Upstream commit 7f36f798f89bf32c0164049cb0e3fd1af613d0bb ] syzbot reported uninit-value: ===================================================== BUG: KMSAN: uninit-value in string_nocheck lib/vsprintf.c:644 [inline] BUG: KMSAN: uninit-value in string+0x4f9/0x6f0 lib/vsprintf.c:725 string_nocheck lib/vsprintf.c:644 [inline] string+0x4f9/0x6f0 lib/vsprintf.c:725 vsnprintf+0x2222/0x3650 lib/vsprintf.c:2806 vprintk_store+0x537/0x2150 kernel/printk/printk.c:2158 vprintk_emit+0x28b/0xab0 kernel/printk/printk.c:2256 vprintk_default+0x86/0xa0 kernel/printk/printk.c:2283 vprintk+0x15f/0x180 kernel/printk/printk_safe.c:50 _printk+0x18d/0x1cf kernel/printk/printk.c:2293 tipc_enable_bearer net/tipc/bearer.c:371 [inline] __tipc_nl_bearer_enable+0x2022/0x22a0 net/tipc/bearer.c:1033 tipc_nl_bearer_enable+0x6c/0xb0 net/tipc/bearer.c:1042 genl_family_rcv_msg_doit net/netlink/genetlink.c:731 [inline] - Do sanity check the attribute length for TIPC_NLA_BEARER_NAME. - Do not use 'illegal name' in printing message. Reported-by: syzbot+e820fdc8ce362f2dea51@syzkaller.appspotmail.com Fixes: cb30a63384bc ("tipc: refactor function tipc_enable_bearer()") Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au> Link: https://lore.kernel.org/r/20220602063053.5892-1-hoang.h.le@dektech.com.au Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-15tipc: fix the timer expires after interval 100msHoang Le
[ Upstream commit 6a7d8cff4a3301087dd139293e9bddcf63827282 ] In the timer callback function tipc_sk_timeout(), we're trying to reschedule another timeout to retransmit a setup request if destination link is congested. But we use the incorrect timeout value (msecs_to_jiffies(100)) instead of (jiffies + msecs_to_jiffies(100)), so that the timer expires immediately, it's irrelevant for original description. In this commit we correct the timeout value in sk_reset_timer() Fixes: 6787927475e5 ("tipc: buffer overflow handling in listener socket") Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au> Link: https://lore.kernel.org/r/20220321042229.314288-1-hoang.h.le@dektech.com.au Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-03-02tipc: Fix end of loop tests for list_for_each_entry()Dan Carpenter
commit a1f8fec4dac8bc7b172b2bdbd881e015261a6322 upstream. These tests are supposed to check if the loop exited via a break or not. However the tests are wrong because if we did not exit via a break then "p" is not a valid pointer. In that case, it's the equivalent of "if (*(u32 *)sr == *last_key) {". That's going to work most of the time, but there is a potential for those to be equal. Fixes: 1593123a6a49 ("tipc: add name table dump to new netlink api") Fixes: 1a1a143daf84 ("tipc: add publication dump to new netlink api") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-16tipc: rate limit warning for received illegal binding updateJon Maloy
[ Upstream commit c7223d687758462826a20e9735305d55bb874c70 ] It would be easy to craft a message containing an illegal binding table update operation. This is handled correctly by the code, but the corresponding warning printout is not rate limited as is should be. We fix this now. Fixes: b97bf3fd8f6a ("[TIPC] Initial merge") Signed-off-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-02-11tipc: improve size validations for received domain recordsJon Maloy
commit 9aa422ad326634b76309e8ff342c246800621216 upstream. The function tipc_mon_rcv() allows a node to receive and process domain_record structs from peer nodes to track their views of the network topology. This patch verifies that the number of members in a received domain record does not exceed the limit defined by MAX_MON_DOMAIN, something that may otherwise lead to a stack overflow. tipc_mon_rcv() is called from the function tipc_link_proto_rcv(), where we are reading a 32 bit message data length field into a uint16. To avert any risk of bit overflow, we add an extra sanity check for this in that function. We cannot see that happen with the current code, but future designers being unaware of this risk, may introduce it by allowing delivery of very large (> 64k) sk buffers from the bearer layer. This potential problem was identified by Eric Dumazet. This fixes CVE-2022-0435 Reported-by: Samuel Page <samuel.page@appgate.com> Reported-by: Eric Dumazet <edumazet@google.com> Fixes: 35c55c9877f8 ("tipc: add neighbor monitoring framework") Signed-off-by: Jon Maloy <jmaloy@redhat.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Reviewed-by: Samuel Page <samuel.page@appgate.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-22tipc: increase timeout in tipc_sk_enqueue()Hoang Le
commit f4bb62e64c88c93060c051195d3bbba804e56945 upstream. In tipc_sk_enqueue() we use hardcoded 2 jiffies to extract socket buffer from generic queue to particular socket. The 2 jiffies is too short in case there are other high priority tasks get CPU cycles for multiple jiffies update. As result, no buffer could be enqueued to particular socket. To solve this, we switch to use constant timeout 20msecs. Then, the function will be expired between 2 jiffies (CONFIG_100HZ) and 20 jiffies (CONFIG_1000HZ). Fixes: c637c1035534 ("tipc: resolve race problem at unicast message reception") Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-22tipc: fix an use-after-free issue in tipc_recvmsgXin Long
commit cc19862ffe454a5b632ca202e5a51bfec9f89fd2 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-22tipc: keep the skb in rcv queue until the whole data is readXin Long
[ Upstream commit f4919ff59c2828064b4156e3c3600a169909bcf4 ] Currently, when userspace reads a datagram with a buffer that is smaller than this datagram, the data will be truncated and only part of it can be received by users. It doesn't seem right that users don't know the datagram size and have to use a huge buffer to read it to avoid the truncation. This patch to fix it by keeping the skb in rcv queue until the whole data is read by users. Only the last msg of the datagram will be marked with MSG_EOR, just as TCP/SCTP does. Note that this will work as above only when MSG_EOR is set in the flags parameter of recvmsg(), so that it won't break any old user applications. 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-08-04tipc: fix sleeping in tipc accept routineHoang Le
[ Upstream commit d237a7f11719ff9320721be5818352e48071aab6 ] The release_sock() is blocking function, it would change the state after sleeping. In order to evaluate the stated condition outside the socket lock context, switch to use wait_woken() instead. Fixes: 6398e23cdb1d8 ("tipc: standardize accept routine") Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-10tipc: fix unique bearer names sanity checkHoang Le
[ Upstream commit f20a46c3044c3f75232b3d0e2d09af9b25efaf45 ] When enabling a bearer by name, we don't sanity check its name with higher slot in bearer list. This may have the effect that the name of an already enabled bearer bypasses the check. To fix the above issue, we just perform an extra checking with all existing bearers. Fixes: cb30a63384bc9 ("tipc: refactor function tipc_enable_bearer()") Cc: stable@vger.kernel.org Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-10tipc: add extack messages for bearer/media failureHoang Le
[ Upstream commit b83e214b2e04204f1fc674574362061492c37245 ] Add extack error messages for -EINVAL errors when enabling bearer, getting/setting properties for a media/bearer Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-03tipc: skb_linearize the head skb when reassembling msgsXin Long
commit b7df21cf1b79ab7026f545e7bf837bd5750ac026 upstream. It's not a good idea to append the frag skb to a skb's frag_list if the frag_list already has skbs from elsewhere, such as this skb was created by pskb_copy() where the frag_list was cloned (all the skbs in it were skb_get'ed) and shared by multiple skbs. However, the new appended frag skb should have been only seen by the current skb. Otherwise, it will cause use after free crashes as this appended frag skb are seen by multiple skbs but it only got skb_get called once. The same thing happens with a skb updated by pskb_may_pull() with a skb_cloned skb. Li Shuang has reported quite a few crashes caused by this when doing testing over macvlan devices: [] kernel BUG at net/core/skbuff.c:1970! [] Call Trace: [] skb_clone+0x4d/0xb0 [] macvlan_broadcast+0xd8/0x160 [macvlan] [] macvlan_process_broadcast+0x148/0x150 [macvlan] [] process_one_work+0x1a7/0x360 [] worker_thread+0x30/0x390 [] kernel BUG at mm/usercopy.c:102! [] Call Trace: [] __check_heap_object+0xd3/0x100 [] __check_object_size+0xff/0x16b [] simple_copy_to_iter+0x1c/0x30 [] __skb_datagram_iter+0x7d/0x310 [] __skb_datagram_iter+0x2a5/0x310 [] skb_copy_datagram_iter+0x3b/0x90 [] tipc_recvmsg+0x14a/0x3a0 [tipc] [] ____sys_recvmsg+0x91/0x150 [] ___sys_recvmsg+0x7b/0xc0 [] kernel BUG at mm/slub.c:305! [] Call Trace: [] <IRQ> [] kmem_cache_free+0x3ff/0x400 [] __netif_receive_skb_core+0x12c/0xc40 [] ? kmem_cache_alloc+0x12e/0x270 [] netif_receive_skb_internal+0x3d/0xb0 [] ? get_rx_page_info+0x8e/0xa0 [be2net] [] be_poll+0x6ef/0xd00 [be2net] [] ? irq_exit+0x4f/0x100 [] net_rx_action+0x149/0x3b0 ... This patch is to fix it by linearizing the head skb if it has frag_list set in tipc_buf_append(). Note that we choose to do this before calling skb_unshare(), as __skb_linearize() will avoid skb_copy(). Also, we can not just drop the frag_list either as the early time. Fixes: 45c8b7b175ce ("tipc: allow non-linear first fragment buffer") Reported-by: Li Shuang <shuali@redhat.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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-03tipc: wait and exit until all work queues are doneXin Long
commit 04c26faa51d1e2fe71cf13c45791f5174c37f986 upstream. On some host, a crash could be triggered simply by repeating these commands several times: # modprobe tipc # tipc bearer enable media udp name UDP1 localip 127.0.0.1 # rmmod tipc [] BUG: unable to handle kernel paging request at ffffffffc096bb00 [] Workqueue: events 0xffffffffc096bb00 [] Call Trace: [] ? process_one_work+0x1a7/0x360 [] ? worker_thread+0x30/0x390 [] ? create_worker+0x1a0/0x1a0 [] ? kthread+0x116/0x130 [] ? kthread_flush_work_fn+0x10/0x10 [] ? ret_from_fork+0x35/0x40 When removing the TIPC module, the UDP tunnel sock will be delayed to release in a work queue as sock_release() can't be done in rtnl_lock(). If the work queue is schedule to run after the TIPC module is removed, kernel will crash as the work queue function cleanup_beareri() code no longer exists when trying to invoke it. To fix it, this patch introduce a member wq_count in tipc_net to track the numbers of work queues in schedule, and wait and exit until all work queues are done in tipc_exit_net(). Fixes: d0f91938bede ("tipc: add ip/udp media type") Reported-by: Shuang Li <shuali@redhat.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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-03Revert "net:tipc: Fix a double free in tipc_sk_mcast_rcv"Hoang Le
commit 75016891357a628d2b8acc09e2b9b2576c18d318 upstream. This reverts commit 6bf24dc0cc0cc43b29ba344b66d78590e687e046. Above fix is not correct and caused memory leak issue. Fixes: 6bf24dc0cc0c ("net:tipc: Fix a double free in tipc_sk_mcast_rcv") Acked-by: Jon Maloy <jmaloy@redhat.com> Acked-by: Tung Nguyen <tung.q.nguyen@dektech.com.au> Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-19tipc: convert dest node's address to network orderHoang Le
[ Upstream commit 1980d37565061ab44bdc2f9e4da477d3b9752e81 ] (struct tipc_link_info)->dest is in network order (__be32), so we must convert the value to network order before assigning. The problem detected by sparse: net/tipc/netlink_compat.c:699:24: warning: incorrect type in assignment (different base types) net/tipc/netlink_compat.c:699:24: expected restricted __be32 [usertype] dest net/tipc/netlink_compat.c:699:24: got int Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-14net:tipc: Fix a double free in tipc_sk_mcast_rcvLv Yunlong
[ Upstream commit 6bf24dc0cc0cc43b29ba344b66d78590e687e046 ] In the if(skb_peek(arrvq) == skb) branch, it calls __skb_dequeue(arrvq) to get the skb by skb = skb_peek(arrvq). Then __skb_dequeue() unlinks the skb from arrvq and returns the skb which equals to skb_peek(arrvq). After __skb_dequeue(arrvq) finished, the skb is freed by kfree_skb(__skb_dequeue(arrvq)) in the first time. Unfortunately, the same skb is freed in the second time by kfree_skb(skb) after the branch completed. My patch removes kfree_skb() in the if(skb_peek(arrvq) == skb) branch, because this skb will be freed by kfree_skb(skb) finally. Fixes: cb1b728096f54 ("tipc: eliminate race condition at multicast reception") Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-23tipc: fix NULL deref in tipc_link_xmit()Hoang Le
[ Upstream commit b77413446408fdd256599daf00d5be72b5f3e7c6 ] The buffer list can have zero skb as following path: tipc_named_node_up()->tipc_node_xmit()->tipc_link_xmit(), so we need to check the list before casting an &sk_buff. Fault report: [] tipc: Bulk publication failure [] general protection fault, probably for non-canonical [#1] PREEMPT [...] [] KASAN: null-ptr-deref in range [0x00000000000000c8-0x00000000000000cf] [] CPU: 0 PID: 0 Comm: swapper/0 Kdump: loaded Not tainted 5.10.0-rc4+ #2 [] Hardware name: Bochs ..., BIOS Bochs 01/01/2011 [] RIP: 0010:tipc_link_xmit+0xc1/0x2180 [] Code: 24 b8 00 00 00 00 4d 39 ec 4c 0f 44 e8 e8 d7 0a 10 f9 48 [...] [] RSP: 0018:ffffc90000006ea0 EFLAGS: 00010202 [] RAX: dffffc0000000000 RBX: ffff8880224da000 RCX: 1ffff11003d3cc0d [] RDX: 0000000000000019 RSI: ffffffff886007b9 RDI: 00000000000000c8 [] RBP: ffffc90000007018 R08: 0000000000000001 R09: fffff52000000ded [] R10: 0000000000000003 R11: fffff52000000dec R12: ffffc90000007148 [] R13: 0000000000000000 R14: 0000000000000000 R15: ffffc90000007018 [] FS: 0000000000000000(0000) GS:ffff888037400000(0000) knlGS:000[...] [] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [] CR2: 00007fffd2db5000 CR3: 000000002b08f000 CR4: 00000000000006f0 Fixes: af9b028e270fd ("tipc: make media xmit call outside node spinlock context") Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au> Link: https://lore.kernel.org/r/20210108071337.3598-1-hoang.h.le@dektech.com.au Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-11tipc: fix a deadlock when flushing scheduled workHoang Huu Le
commit d966ddcc38217a6110a6a0ff37ad2dee7d42e23e upstream. In the commit fdeba99b1e58 ("tipc: fix use-after-free in tipc_bcast_get_mode"), we're trying to make sure the tipc_net_finalize_work work item finished if it enqueued. But calling flush_scheduled_work() is not just affecting above work item but either any scheduled work. This has turned out to be overkill and caused to deadlock as syzbot reported: ====================================================== WARNING: possible circular locking dependency detected 5.9.0-rc2-next-20200828-syzkaller #0 Not tainted ------------------------------------------------------ kworker/u4:6/349 is trying to acquire lock: ffff8880aa063d38 ((wq_completion)events){+.+.}-{0:0}, at: flush_workqueue+0xe1/0x13e0 kernel/workqueue.c:2777 but task is already holding lock: ffffffff8a879430 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xb10 net/core/net_namespace.c:565 [...] Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(pernet_ops_rwsem); lock(&sb->s_type->i_mutex_key#13); lock(pernet_ops_rwsem); lock((wq_completion)events); *** DEADLOCK *** [...] v1: To fix the original issue, we replace above calling by introducing a bit flag. When a namespace cleaned-up, bit flag is set to zero and: - tipc_net_finalize functionial just does return immediately. - tipc_net_finalize_work does not enqueue into the scheduled work queue. v2: Use cancel_work_sync() helper to make sure ONLY the tipc_net_finalize_work() stopped before releasing bcbase object. Reported-by: syzbot+d5aa7e0385f6a5d0f4fd@syzkaller.appspotmail.com Fixes: fdeba99b1e58 ("tipc: fix use-after-free in tipc_bcast_get_mode") Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: Hoang Huu Le <hoang.h.le@dektech.com.au> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-18tipc: fix memory leak in tipc_topsrv_start()Wang Hai
[ Upstream commit fa6882c63621821f73cc806f291208e1c6ea6187 ] kmemleak report a memory leak as follows: unreferenced object 0xffff88810a596800 (size 512): comm "ip", pid 21558, jiffies 4297568990 (age 112.120s) hex dump (first 32 bytes): 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N.......... ff ff ff ff ff ff ff ff 00 83 60 b0 ff ff ff ff ..........`..... backtrace: [<0000000022bbe21f>] tipc_topsrv_init_net+0x1f3/0xa70 [<00000000fe15ddf7>] ops_init+0xa8/0x3c0 [<00000000138af6f2>] setup_net+0x2de/0x7e0 [<000000008c6807a3>] copy_net_ns+0x27d/0x530 [<000000006b21adbd>] create_new_namespaces+0x382/0xa30 [<00000000bb169746>] unshare_nsproxy_namespaces+0xa1/0x1d0 [<00000000fe2e42bc>] ksys_unshare+0x39c/0x780 [<0000000009ba3b19>] __x64_sys_unshare+0x2d/0x40 [<00000000614ad866>] do_syscall_64+0x56/0xa0 [<00000000a1b5ca3c>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 'srv' is malloced in tipc_topsrv_start() but not free before leaving from the error handling cases. We need to free it. Fixes: 5c45ab24ac77 ("tipc: make struct tipc_server private for server.c") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Wang Hai <wanghai38@huawei.com> Link: https://lore.kernel.org/r/20201109140913.47370-1-wanghai38@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-10tipc: fix use-after-free in tipc_bcast_get_modeHoang Huu Le
commit fdeba99b1e58ecd18c2940c453e19e4ef20ff591 upstream. Syzbot has reported those issues as: ================================================================== BUG: KASAN: use-after-free in tipc_bcast_get_mode+0x3ab/0x400 net/tipc/bcast.c:759 Read of size 1 at addr ffff88805e6b3571 by task kworker/0:6/3850 CPU: 0 PID: 3850 Comm: kworker/0:6 Not tainted 5.8.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events tipc_net_finalize_work Thread 1's call trace: [...] kfree+0x103/0x2c0 mm/slab.c:3757 <- bcbase releasing tipc_bcast_stop+0x1b0/0x2f0 net/tipc/bcast.c:721 tipc_exit_net+0x24/0x270 net/tipc/core.c:112 [...] Thread 2's call trace: [...] tipc_bcast_get_mode+0x3ab/0x400 net/tipc/bcast.c:759 <- bcbase has already been freed by Thread 1 tipc_node_broadcast+0x9e/0xcc0 net/tipc/node.c:1744 tipc_nametbl_publish+0x60b/0x970 net/tipc/name_table.c:752 tipc_net_finalize net/tipc/net.c:141 [inline] tipc_net_finalize+0x1fa/0x310 net/tipc/net.c:131 tipc_net_finalize_work+0x55/0x80 net/tipc/net.c:150 [...] ================================================================== BUG: KASAN: use-after-free in tipc_named_reinit+0xef/0x290 net/tipc/name_distr.c:344 Read of size 8 at addr ffff888052ab2000 by task kworker/0:13/30628 CPU: 0 PID: 30628 Comm: kworker/0:13 Not tainted 5.8.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events tipc_net_finalize_work Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1f0/0x31e lib/dump_stack.c:118 print_address_description+0x66/0x5a0 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report+0x132/0x1d0 mm/kasan/report.c:530 tipc_named_reinit+0xef/0x290 net/tipc/name_distr.c:344 tipc_net_finalize+0x85/0xe0 net/tipc/net.c:138 tipc_net_finalize_work+0x50/0x70 net/tipc/net.c:150 process_one_work+0x789/0xfc0 kernel/workqueue.c:2269 worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415 kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 [...] Freed by task 14058: save_stack mm/kasan/common.c:48 [inline] set_track mm/kasan/common.c:56 [inline] kasan_set_free_info mm/kasan/common.c:316 [inline] __kasan_slab_free+0x114/0x170 mm/kasan/common.c:455 __cache_free mm/slab.c:3426 [inline] kfree+0x10a/0x220 mm/slab.c:3757 tipc_exit_net+0x29/0x50 net/tipc/core.c:113 ops_exit_list net/core/net_namespace.c:186 [inline] cleanup_net+0x708/0xba0 net/core/net_namespace.c:603 process_one_work+0x789/0xfc0 kernel/workqueue.c:2269 worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415 kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 Fix it by calling flush_scheduled_work() to make sure the tipc_net_finalize_work() stopped before releasing bcbase object. Reported-by: syzbot+6ea1f7a8df64596ef4d7@syzkaller.appspotmail.com Reported-by: syzbot+e9cc557752ab126c1b99@syzkaller.appspotmail.com Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: Hoang Huu Le <hoang.h.le@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-01tipc: fix memory leak caused by tipc_buf_append()Tung Nguyen
[ Upstream commit ceb1eb2fb609c88363e06618b8d4bbf7815a4e03 ] Commit ed42989eab57 ("tipc: fix the skb_unshare() in tipc_buf_append()") replaced skb_unshare() with skb_copy() to not reduce the data reference counter of the original skb intentionally. This is not the correct way to handle the cloned skb because it causes memory leak in 2 following cases: 1/ Sending multicast messages via broadcast link The original skb list is cloned to the local skb list for local destination. After that, the data reference counter of each skb in the original list has the value of 2. This causes each skb not to be freed after receiving ACK: tipc_link_advance_transmq() { ... /* release skb */ __skb_unlink(skb, &l->transmq); kfree_skb(skb); <-- memory exists after being freed } 2/ Sending multicast messages via replicast link Similar to the above case, each skb cannot be freed after purging the skb list: tipc_mcast_xmit() { ... __skb_queue_purge(pkts); <-- memory exists after being freed } This commit fixes this issue by using skb_unshare() instead. Besides, to avoid use-after-free error reported by KASAN, the pointer to the fragment is set to NULL before calling skb_unshare() to make sure that the original skb is not freed after freeing the fragment 2 times in case skb_unshare() returns NULL. Fixes: ed42989eab57 ("tipc: fix the skb_unshare() in tipc_buf_append()") Acked-by: Jon Maloy <jmaloy@redhat.com> Reported-by: Thang Hoang Ngo <thang.h.ngo@dektech.com.au> Signed-off-by: Tung Nguyen <tung.q.nguyen@dektech.com.au> Reviewed-by: Xin Long <lucien.xin@gmail.com> Acked-by: Cong Wang <xiyou.wangcong@gmail.com> Link: https://lore.kernel.org/r/20201027032403.1823-1-tung.q.nguyen@dektech.com.au Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-29tipc: fix the skb_unshare() in tipc_buf_append()Cong Wang
[ Upstream commit ed42989eab57d619667d7e87dfbd8fe207db54fe ] skb_unshare() drops a reference count on the old skb unconditionally, so in the failure case, we end up freeing the skb twice here. And because the skb is allocated in fclone and cloned by caller tipc_msg_reassemble(), the consequence is actually freeing the original skb too, thus triggered the UAF by syzbot. Fix this by replacing this skb_unshare() with skb_cloned()+skb_copy(). Fixes: ff48b6222e65 ("tipc: use skb_unshare() instead in tipc_buf_append()") Reported-and-tested-by: syzbot+e96a7ba46281824cc46a@syzkaller.appspotmail.com Cc: Jon Maloy <jmaloy@redhat.com> Cc: Ying Xue <ying.xue@windriver.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-01tipc: fix memory leak in service subscriptingTuong Lien
[ Upstream commit 0771d7df819284d46cf5cfb57698621b503ec17f ] Upon receipt of a service subscription request from user via a topology connection, one 'sub' object will be allocated in kernel, so it will be able to send an event of the service if any to the user correspondingly then. Also, in case of any failure, the connection will be shutdown and all the pertaining 'sub' objects will be freed. However, there is a race condition as follows resulting in memory leak: receive-work connection send-work | | | sub-1 |<------//-------| | sub-2 |<------//-------| | | |<---------------| evt for sub-x sub-3 |<------//-------| | : : : : : : | /--------| | | | * peer closed | | | | | | | |<-------X-------| evt for sub-y | | |<===============| sub-n |<------/ X shutdown | -> orphan | | That is, the 'receive-work' may get the last subscription request while the 'send-work' is shutting down the connection due to peer close. We had a 'lock' on the connection, so the two actions cannot be carried out simultaneously. If the last subscription is allocated e.g. 'sub-n', before the 'send-work' closes the connection, there will be no issue at all, the 'sub' objects will be freed. In contrast the last subscription will become orphan since the connection was closed, and we released all references. This commit fixes the issue by simply adding one test if the connection remains in 'connected' state right after we obtain the connection lock, then a subscription object can be created as usual, otherwise we ignore it. Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jmaloy@redhat.com> Reported-by: Thang Ngo <thang.h.ngo@dektech.com.au> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01tipc: fix link overflow issue at socket shutdownTuong Lien
[ Upstream commit 49afb806cb650dd1f06f191994f3aa657d264009 ] When a socket is suddenly shutdown or released, it will reject all the unreceived messages in its receive queue. This applies to a connected socket too, whereas there is only one 'FIN' message required to be sent back to its peer in this case. In case there are many messages in the queue and/or some connections with such messages are shutdown at the same time, the link layer will easily get overflowed at the 'TIPC_SYSTEM_IMPORTANCE' backlog level because of the message rejections. As a result, the link will be taken down. Moreover, immediately when the link is re-established, the socket layer can continue to reject the messages and the same issue happens... The commit refactors the '__tipc_shutdown()' function to only send one 'FIN' in the situation mentioned above. For the connectionless case, it is unavoidable but usually there is no rejections for such socket messages because they are 'dest-droppable' by default. In addition, the new code makes the other socket states clear (e.g.'TIPC_LISTEN') and treats as a separate case to avoid misbehaving. Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-26tipc: use skb_unshare() instead in tipc_buf_append()Xin Long
[ Upstream commit ff48b6222e65ebdba5a403ef1deba6214e749193 ] In tipc_buf_append() it may change skb's frag_list, and it causes problems when this skb is cloned. skb_unclone() doesn't really make this skb's flag_list available to change. Shuang Li has reported an use-after-free issue because of this when creating quite a few macvlan dev over the same dev, where the broadcast packets will be cloned and go up to the stack: [ ] BUG: KASAN: use-after-free in pskb_expand_head+0x86d/0xea0 [ ] Call Trace: [ ] dump_stack+0x7c/0xb0 [ ] print_address_description.constprop.7+0x1a/0x220 [ ] kasan_report.cold.10+0x37/0x7c [ ] check_memory_region+0x183/0x1e0 [ ] pskb_expand_head+0x86d/0xea0 [ ] process_backlog+0x1df/0x660 [ ] net_rx_action+0x3b4/0xc90 [ ] [ ] Allocated by task 1786: [ ] kmem_cache_alloc+0xbf/0x220 [ ] skb_clone+0x10a/0x300 [ ] macvlan_broadcast+0x2f6/0x590 [macvlan] [ ] macvlan_process_broadcast+0x37c/0x516 [macvlan] [ ] process_one_work+0x66a/0x1060 [ ] worker_thread+0x87/0xb10 [ ] [ ] Freed by task 3253: [ ] kmem_cache_free+0x82/0x2a0 [ ] skb_release_data+0x2c3/0x6e0 [ ] kfree_skb+0x78/0x1d0 [ ] tipc_recvmsg+0x3be/0xa40 [tipc] So fix it by using skb_unshare() instead, which would create a new skb for the cloned frag and it'll be safe to change its frag_list. The similar things were also done in sctp_make_reassembled_event(), which is using skb_copy(). Reported-by: Shuang Li <shuali@redhat.com> Fixes: 37e22164a8a3 ("tipc: rename and move message reassembly function") Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-26tipc: fix shutdown() of connection oriented socketTetsuo Handa
[ Upstream commit a4b5cc9e10803ecba64a7d54c0f47e4564b4a980 ] I confirmed that the problem fixed by commit 2a63866c8b51a3f7 ("tipc: fix shutdown() of connectionless socket") also applies to stream socket. ---------- #include <sys/socket.h> #include <unistd.h> #include <sys/wait.h> int main(int argc, char *argv[]) { int fds[2] = { -1, -1 }; socketpair(PF_TIPC, SOCK_STREAM /* or SOCK_DGRAM */, 0, fds); if (fork() == 0) _exit(read(fds[0], NULL, 1)); shutdown(fds[0], SHUT_RDWR); /* This must make read() return. */ wait(NULL); /* To be woken up by _exit(). */ return 0; } ---------- Since shutdown(SHUT_RDWR) should affect all processes sharing that socket, unconditionally setting sk->sk_shutdown to SHUTDOWN_MASK will be the right behavior. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-26tipc: Fix memory leak in tipc_group_create_member()Peilin Ye
[ Upstream commit bb3a420d47ab00d7e1e5083286cab15235a96680 ] tipc_group_add_to_tree() returns silently if `key` matches `nkey` of an existing node, causing tipc_group_create_member() to leak memory. Let tipc_group_add_to_tree() return an error in such a case, so that tipc_group_create_member() can handle it properly. Fixes: 75da2163dbb6 ("tipc: introduce communication groups") Reported-and-tested-by: syzbot+f95d90c454864b3b5bc9@syzkaller.appspotmail.com Cc: Hillf Danton <hdanton@sina.com> Link: https://syzkaller.appspot.com/bug?id=048390604fe1b60df34150265479202f10e13aff Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-12tipc: fix shutdown() of connectionless socketTetsuo Handa
[ Upstream commit 2a63866c8b51a3f72cea388dfac259d0e14c4ba6 ] syzbot is reporting hung task at nbd_ioctl() [1], for there are two problems regarding TIPC's connectionless socket's shutdown() operation. ---------- #include <fcntl.h> #include <sys/socket.h> #include <sys/ioctl.h> #include <linux/nbd.h> #include <unistd.h> int main(int argc, char *argv[]) { const int fd = open("/dev/nbd0", 3); alarm(5); ioctl(fd, NBD_SET_SOCK, socket(PF_TIPC, SOCK_DGRAM, 0)); ioctl(fd, NBD_DO_IT, 0); /* To be interrupted by SIGALRM. */ return 0; } ---------- One problem is that wait_for_completion() from flush_workqueue() from nbd_start_device_ioctl() from nbd_ioctl() cannot be completed when nbd_start_device_ioctl() received a signal at wait_event_interruptible(), for tipc_shutdown() from kernel_sock_shutdown(SHUT_RDWR) from nbd_mark_nsock_dead() from sock_shutdown() from nbd_start_device_ioctl() is failing to wake up a WQ thread sleeping at wait_woken() from tipc_wait_for_rcvmsg() from sock_recvmsg() from sock_xmit() from nbd_read_stat() from recv_work() scheduled by nbd_start_device() from nbd_start_device_ioctl(). Fix this problem by always invoking sk->sk_state_change() (like inet_shutdown() does) when tipc_shutdown() is called. The other problem is that tipc_wait_for_rcvmsg() cannot return when tipc_shutdown() is called, for tipc_shutdown() sets sk->sk_shutdown to SEND_SHUTDOWN (despite "how" is SHUT_RDWR) while tipc_wait_for_rcvmsg() needs sk->sk_shutdown set to RCV_SHUTDOWN or SHUTDOWN_MASK. Fix this problem by setting sk->sk_shutdown to SHUTDOWN_MASK (like inet_shutdown() does) when the socket is connectionless. [1] https://syzkaller.appspot.com/bug?id=3fe51d307c1f0a845485cf1798aa059d12bf18b2 Reported-by: syzbot <syzbot+e36f41d207137b5d12f7@syzkaller.appspotmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-03tipc: fix uninit skb->data in tipc_nl_compat_dumpit()Cong Wang
[ Upstream commit 47733f9daf4fe4f7e0eb9e273f21ad3a19130487 ] __tipc_nl_compat_dumpit() has two callers, and it expects them to pass a valid nlmsghdr via arg->data. This header is artificial and crafted just for __tipc_nl_compat_dumpit(). tipc_nl_compat_publ_dump() does so by putting a genlmsghdr as well as some nested attribute, TIPC_NLA_SOCK. But the other caller tipc_nl_compat_dumpit() does not, this leaves arg->data uninitialized on this call path. Fix this by just adding a similar nlmsghdr without any payload in tipc_nl_compat_dumpit(). This bug exists since day 1, but the recent commit 6ea67769ff33 ("net: tipc: prepare attrs in __tipc_nl_compat_dumpit()") makes it easier to appear. Reported-and-tested-by: syzbot+0e7181deafa7e0b79923@syzkaller.appspotmail.com Fixes: d0796d1ef63d ("tipc: convert legacy nl bearer dump to nl compat") Cc: Jon Maloy <jmaloy@redhat.com> Cc: Ying Xue <ying.xue@windriver.com> Cc: Richard Alpe <richard.alpe@ericsson.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-03tipc: block BH before using dst_cacheEric Dumazet
[ Upstream commit 1378817486d6860f6a927f573491afe65287abf1 ] dst_cache_get() documents it must be used with BH disabled. sysbot reported : BUG: using smp_processor_id() in preemptible [00000000] code: /21697 caller is dst_cache_get+0x3a/0xb0 net/core/dst_cache.c:68 CPU: 0 PID: 21697 Comm: Not tainted 5.7.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 check_preemption_disabled lib/smp_processor_id.c:47 [inline] debug_smp_processor_id.cold+0x88/0x9b lib/smp_processor_id.c:57 dst_cache_get+0x3a/0xb0 net/core/dst_cache.c:68 tipc_udp_xmit.isra.0+0xb9/0xad0 net/tipc/udp_media.c:164 tipc_udp_send_msg+0x3e6/0x490 net/tipc/udp_media.c:244 tipc_bearer_xmit_skb+0x1de/0x3f0 net/tipc/bearer.c:526 tipc_enable_bearer+0xb2f/0xd60 net/tipc/bearer.c:331 __tipc_nl_bearer_enable+0x2bf/0x390 net/tipc/bearer.c:995 tipc_nl_bearer_enable+0x1e/0x30 net/tipc/bearer.c:1003 genl_family_rcv_msg_doit net/netlink/genetlink.c:673 [inline] genl_family_rcv_msg net/netlink/genetlink.c:718 [inline] genl_rcv_msg+0x627/0xdf0 net/netlink/genetlink.c:735 netlink_rcv_skb+0x15a/0x410 net/netlink/af_netlink.c:2469 genl_rcv+0x24/0x40 net/netlink/genetlink.c:746 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x537/0x740 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x882/0xe10 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x6bf/0x7e0 net/socket.c:2362 ___sys_sendmsg+0x100/0x170 net/socket.c:2416 __sys_sendmsg+0xec/0x1b0 net/socket.c:2449 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca29 Fixes: e9c1a793210f ("tipc: add dst_cache support for udp media") Cc: Xin Long <lucien.xin@gmail.com> Cc: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-14tipc: fix partial topology connection closureTuong Lien
[ Upstream commit 980d69276f3048af43a045be2925dacfb898a7be ] When an application connects to the TIPC topology server and subscribes to some services, a new connection is created along with some objects - 'tipc_subscription' to store related data correspondingly... However, there is one omission in the connection handling that when the connection or application is orderly shutdown (e.g. via SIGQUIT, etc.), the connection is not closed in kernel, the 'tipc_subscription' objects are not freed too. This results in: - The maximum number of subscriptions (65535) will be reached soon, new subscriptions will be rejected; - TIPC module cannot be removed (unless the objects are somehow forced to release first); The commit fixes the issue by closing the connection if the 'recvmsg()' returns '0' i.e. when the peer is shutdown gracefully. It also includes the other unexpected cases. Acked-by: Jon Maloy <jmaloy@redhat.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-18tipc: add missing attribute validation for MTU propertyJakub Kicinski
[ Upstream commit 213320a67962ff6e7b83b704d55cbebc341426db ] Add missing attribute validation for TIPC_NLA_PROP_MTU to the netlink policy. Fixes: 901271e0403a ("tipc: implement configuration of UDP media MTU") Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-26tipc: fix wrong timeout input for tipc_wait_for_cond()Tung Nguyen
commit 12db3c8083fcab4270866a88191933f2d9f24f89 upstream. In function __tipc_shutdown(), the timeout value passed to tipc_wait_for_cond() is not jiffies. This commit fixes it by converting that value from milliseconds to jiffies. Fixes: 365ad353c256 ("tipc: reduce risk of user starvation during link congestion") Signed-off-by: Tung Nguyen <tung.q.nguyen@dektech.com.au> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-26tipc: fix wrong socket reference counter after tipc_sk_timeout() returnsTung Nguyen
commit 91a4a3eb433e4d786420c41f3c08d1d16c605962 upstream. When tipc_sk_timeout() is executed but user space is grabbing ownership, this function rearms itself and returns. However, the socket reference counter is not reduced. This causes potential unexpected behavior. This commit fixes it by calling sock_put() before tipc_sk_timeout() returns in the above-mentioned case. Fixes: afe8792fec69 ("tipc: refactor function tipc_sk_timeout()") Signed-off-by: Tung Nguyen <tung.q.nguyen@dektech.com.au> Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>