Xin Long ce69bdac23 tipc: fix a null-ptr-deref in tipc_topsrv_accept ... [ 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: 0ef897be12 ("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>		2022-11-03 23:52:30 +09:00
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addr.c
addr.h
bcast.c	tipc: clean up skb list lock handling on send path	2020-07-29 10:16:47 +02:00
bcast.h
bearer.c	tipc: check attribute length for bearer name	2022-06-14 16:59:34 +02:00
bearer.h
core.c	tipc: fix use-after-free in tipc_bcast_get_mode	2020-11-10 12:35:53 +01:00
core.h
diag.c
discover.c	tipc: Fix recognition of trial period	2022-11-03 23:52:25 +09:00
discover.h
eth_media.c
group.c	tipc: Fix memory leak in tipc_group_create_member()	2020-09-26 18:01:30 +02:00
group.h
ib_media.c
Kconfig
link.c	tipc: improve size validations for received domain records	2022-02-11 08:44:59 +01:00
link.h
Makefile
monitor.c	tipc: fix shift wrapping bug in map_get()	2022-09-15 12:17:05 +02:00
monitor.h
msg.c	tipc: skb_linearize the head skb when reassembling msgs	2021-06-03 08:38:08 +02:00
msg.h
name_distr.c	tipc: rate limit warning for received illegal binding update	2022-02-16 12:51:46 +01:00
name_distr.h
name_table.c	tipc: Fix end of loop tests for list_for_each_entry()	2022-03-02 11:38:11 +01:00
name_table.h
net.c
net.h
netlink_compat.c	tipc: convert dest node's address to network order	2021-05-22 10:59:39 +02:00
netlink.c
netlink.h
node.c	tipc: clean up skb list lock handling on send path	2020-07-29 10:16:47 +02:00
node.h
socket.c	net: tipc: fix possible refcount leak in tipc_sk_create()	2022-07-21 21:09:30 +02:00
socket.h
subscr.c
subscr.h
sysctl.c
topsrv.c	tipc: fix a null-ptr-deref in tipc_topsrv_accept	2022-11-03 23:52:30 +09:00
topsrv.h
udp_media.c
udp_media.h