linux/net/tipc
Xin Long 82cb4e4612 tipc: fix a null-ptr-deref in tipc_topsrv_accept
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>
2022-10-20 21:08:17 -07:00
..
addr.c tipc: introduce new unified address type for internal use 2021-03-17 11:51:04 -07:00
addr.h tipc: introduce new unified address type for internal use 2021-03-17 11:51:04 -07:00
bcast.c net: tipc: fix FB_MTU eat two pages 2021-06-28 13:31:57 -07:00
bcast.h tipc: update a binding service via broadcast 2020-06-17 08:53:34 -07:00
bearer.c net: rename reference+tracking helpers 2022-06-09 21:52:55 -07:00
bearer.h tipc: constify dev_addr passing 2021-10-13 09:40:46 -07:00
core.c tipc: fix use-after-free Read in tipc_named_reinit 2022-06-17 11:39:10 +01:00
core.h tipc: simplify the finalize work queue 2021-05-18 13:22:09 -07:00
crypto.c tipc: fix a bit overflow in tipc_crypto_key_rcv() 2022-02-13 12:12:25 +00:00
crypto.h net/tipc: fix tipc header files for kernel-doc 2020-12-01 15:37:41 -08:00
diag.c
discover.c tipc: Fix recognition of trial period 2022-10-14 08:17:52 +01:00
discover.h
eth_media.c tipc: constify dev_addr passing 2021-10-13 09:40:46 -07:00
group.c tipc: update address terminology in code 2020-11-27 17:34:01 -08:00
group.h tipc: update address terminology in code 2020-11-27 17:34:01 -08:00
ib_media.c tipc: constify dev_addr passing 2021-10-13 09:40:46 -07:00
Kconfig tipc: not enable tipc when ipv6 works as a module 2020-08-16 21:04:55 -07:00
link.c tipc: fix incorrect order of state message data sanity check 2022-03-08 22:18:42 -08:00
link.h tipc: simplify the finalize work queue 2021-05-18 13:22:09 -07:00
Makefile tipc: remove meaningless assignment in Makefile 2020-01-08 12:38:54 -08:00
monitor.c tipc: fix shift wrapping bug in map_get() 2022-09-02 12:26:29 +01:00
monitor.h tipc: update mon's self addr when node addr generated 2019-11-12 19:45:45 -08:00
msg.c net: tipc: replace align() with ALIGN in msg.c 2021-06-28 13:31:57 -07:00
msg.h net: tipc: remove unused static inlines 2022-01-27 13:53:27 +00:00
name_distr.c net/tipc: Remove unused struct distr_queue_item 2022-09-29 18:48:32 -07:00
name_distr.h net/tipc: fix tipc header files for kernel-doc 2020-12-01 15:37:41 -08:00
name_table.c tipc: cleanup unused function 2022-06-17 11:43:57 +01:00
name_table.h tipc: cleanup unused function 2022-06-17 11:43:57 +01:00
net.c tipc: simplify the finalize work queue 2021-05-18 13:22:09 -07:00
net.h tipc: fix a deadlock when flushing scheduled work 2020-09-07 12:08:53 -07:00
netlink_compat.c genetlink: start to validate reserved header bytes 2022-08-29 12:47:15 +01:00
netlink.c genetlink: start to validate reserved header bytes 2022-08-29 12:47:15 +01:00
netlink.h net: tipc: allocate attrs locally instead of using genl_family_attrbuf in compat_dumpit() 2019-10-06 15:44:47 +02:00
node.c tipc: move bc link creation back to tipc_node_create 2022-06-27 11:51:56 +01:00
node.h tipc: add automatic session key exchange 2020-09-18 13:58:37 -07:00
socket.c treewide: use prandom_u32_max() when possible, part 1 2022-10-11 17:42:55 -06:00
socket.h tipc: add stricter control of reserved service types 2020-10-30 08:19:18 -07:00
subscr.c tipc:subscr.c: fix a spelling mistake 2021-06-10 13:48:43 -07:00
subscr.h tipc: fix htmldoc and smatch warnings 2021-03-29 16:28:50 -07:00
sysctl.c tipc: add automatic session key exchange 2020-09-18 13:58:37 -07:00
topsrv.c tipc: fix a null-ptr-deref in tipc_topsrv_accept 2022-10-20 21:08:17 -07:00
topsrv.h
trace.c net/tipc: fix various kernel-doc warnings 2020-12-01 15:37:46 -08:00
trace.h tipc: add support for broadcast rcv stats dumping 2020-05-26 15:16:52 -07:00
udp_media.c tipc: wait and exit until all work queues are done 2021-05-17 14:07:48 -07:00
udp_media.h