linux-stable.git/net/netfilter, branch v4.14.44 Linux kernel stable tree netfilter: nf_tables: can't fail after linking rule into active rule list 2018-05-22T16:53:58+00:00 Florian Westphal fw@strlen.de 2018-04-10T07:30:27+00:00 d233f8d5bdd39ef13112147d8659bc2f5b9f6b8f commit 569ccae68b38654f04b6842b034aa33857f605fe upstream. rules in nftables a free'd using kfree, but protected by rcu, i.e. we must wait for a grace period to elapse. Normal removal patch does this, but nf_tables_newrule() doesn't obey this rule during error handling. It calls nft_trans_rule_add() *after* linking rule, and, if that fails to allocate memory, it unlinks the rule and then kfree() it -- this is unsafe. Switch order -- first add rule to transaction list, THEN link it to public list. Note: nft_trans_rule_add() uses GFP_KERNEL; it will not fail so this is not a problem in practice (spotted only during code review). Fixes: 0628b123c96d12 ("netfilter: nfnetlink: add batch support and use it from nf_tables") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 569ccae68b38654f04b6842b034aa33857f605fe upstream.

rules in nftables a free'd using kfree, but protected by rcu, i.e. we
must wait for a grace period to elapse.

Normal removal patch does this, but nf_tables_newrule() doesn't obey
this rule during error handling.

It calls nft_trans_rule_add() *after* linking rule, and, if that
fails to allocate memory, it unlinks the rule and then kfree() it --
this is unsafe.

Switch order -- first add rule to transaction list, THEN link it
to public list.

Note: nft_trans_rule_add() uses GFP_KERNEL; it will not fail so this
is not a problem in practice (spotted only during code review).

Fixes: 0628b123c96d12 ("netfilter: nfnetlink: add batch support and use it from nf_tables")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
netfilter: nf_tables: free set name in error path 2018-05-22T16:53:58+00:00 Florian Westphal fw@strlen.de 2018-04-10T07:00:24+00:00 321bc88ec098845ec93d047858a010d41be26ed9 commit 2f6adf481527c8ab8033c601f55bfb5b3712b2ac upstream. set->name must be free'd here in case ops->init fails. Fixes: 387454901bd6 ("netfilter: nf_tables: Allow set names of up to 255 chars") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 2f6adf481527c8ab8033c601f55bfb5b3712b2ac upstream.

set->name must be free'd here in case ops->init fails.

Fixes: 387454901bd6 ("netfilter: nf_tables: Allow set names of up to 255 chars")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipvs: fix rtnl_lock lockups caused by start_sync_thread 2018-05-16T08:10:22+00:00 Julian Anastasov ja@ssi.bg 2018-04-07T12:50:47+00:00 88c43b469db5d4c39fba20c293b44cbe78b66e3a commit 5c64576a77894a50be80be0024bed27171b55989 upstream. syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2] We have 2 problems in start_sync_thread if error path is taken, eg. on memory allocation error or failure to configure sockets for mcast group or addr/port binding: 1. recursive locking: holding rtnl_lock while calling sock_release which in turn calls again rtnl_lock in ip_mc_drop_socket to leave the mcast group, as noticed by Florian Westphal. Additionally, sock_release can not be called while holding sync_mutex (ABBA deadlock). 2. task hung: holding rtnl_lock while calling kthread_stop to stop the running kthreads. As the kthreads do the same to leave the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock) they hang. Fix the problems by calling rtnl_unlock early in the error path, now sock_release is called after unlocking both mutexes. Problem 3 (task hung reported by syzkaller [2]) is variant of problem 2: use _trylock to prevent one user to call rtnl_lock and then while waiting for sync_mutex to block kthreads that execute sock_release when they are stopped by stop_sync_thread. [1] IPVS: stopping backup sync thread 4500 ... WARNING: possible recursive locking detected 4.16.0-rc7+ #3 Not tainted -------------------------------------------- syzkaller688027/4497 is trying to acquire lock: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 but task is already holding lock: IPVS: stopping backup sync thread 4495 ... (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(rtnl_mutex); lock(rtnl_mutex); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by syzkaller688027/4497: #0: (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 #1: (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>] do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388 stack backtrace: CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 print_deadlock_bug kernel/locking/lockdep.c:1761 [inline] check_deadlock kernel/locking/lockdep.c:1805 [inline] validate_chain kernel/locking/lockdep.c:2401 [inline] __lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643 inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413 sock_release+0x8d/0x1e0 net/socket.c:595 start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924 do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115 ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261 udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975 SYSC_setsockopt net/socket.c:1849 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1828 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x446a69 RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69 RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000 R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8 R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60 [2] IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4, id = 0 IPVS: stopping backup sync thread 25415 ... INFO: task syz-executor7:25421 blocked for more than 120 seconds. Not tainted 4.16.0-rc6+ #284 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor7 D23688 25421 4408 0x00000004 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440 schedule+0xf5/0x430 kernel/sched/core.c:3499 schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777 do_wait_for_common kernel/sched/completion.c:86 [inline] __wait_for_common kernel/sched/completion.c:107 [inline] wait_for_common kernel/sched/completion.c:118 [inline] wait_for_completion+0x415/0x770 kernel/sched/completion.c:139 kthread_stop+0x14a/0x7a0 kernel/kthread.c:530 stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996 do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115 ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253 sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039 SYSC_setsockopt net/socket.c:1850 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1829 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x454889 RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889 RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017 RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000 R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001 Showing all locks held in the system: 2 locks held by khungtaskd/868: #0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>] debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 1 lock held by rsyslogd/4247: #0: (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>] __fdget_pos+0x12b/0x190 fs/file.c:765 2 locks held by getty/4338: #0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4339: #0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4340: #0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4341: #0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4342: #0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4343: #0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4344: #0: (&tty->ldisc_sem){++++}, at: [<00000000bee98654>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 3 locks held by kworker/0:5/6494: #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline] #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: [<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084 #1: ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088 #2: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 1 lock held by syz-executor7/25421: #0: (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>] do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393 2 locks held by syz-executor7/25427: #0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 #1: (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>] do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388 1 lock held by syz-executor7/25435: #0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 1 lock held by ipvs-b:2:0/25415: #0: (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early") Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Simon Horman <horms@verge.net.au> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Cc: Zubin Mithra <zsm@chromium.org> Cc: Guenter Roeck <groeck@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 5c64576a77894a50be80be0024bed27171b55989 upstream.

syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]

We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:

1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).

2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.

Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.

Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.

[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
  (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74

but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
  (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74

other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(rtnl_mutex);
   lock(rtnl_mutex);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

2 locks held by syzkaller688027/4497:
  #0:  (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
  #1:  (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388

stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:17 [inline]
  dump_stack+0x194/0x24d lib/dump_stack.c:53
  print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
  check_deadlock kernel/locking/lockdep.c:1805 [inline]
  validate_chain kernel/locking/lockdep.c:2401 [inline]
  __lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
  lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
  __mutex_lock_common kernel/locking/mutex.c:756 [inline]
  __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
  mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
  rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
  ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
  inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
  sock_release+0x8d/0x1e0 net/socket.c:595
  start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
  do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
  nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
  nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
  ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
  udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
  sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
  SYSC_setsockopt net/socket.c:1849 [inline]
  SyS_setsockopt+0x189/0x360 net/socket.c:1828
  do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60

[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
       Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7   D23688 25421   4408 0x00000004
Call Trace:
  context_switch kernel/sched/core.c:2862 [inline]
  __schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
  schedule+0xf5/0x430 kernel/sched/core.c:3499
  schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
  do_wait_for_common kernel/sched/completion.c:86 [inline]
  __wait_for_common kernel/sched/completion.c:107 [inline]
  wait_for_common kernel/sched/completion.c:118 [inline]
  wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
  kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
  stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
  do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
  nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
  nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
  ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
  sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
  sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
  SYSC_setsockopt net/socket.c:1850 [inline]
  SyS_setsockopt+0x189/0x360 net/socket.c:1829
  do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001

Showing all locks held in the system:
2 locks held by khungtaskd/868:
  #0:  (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
  #0:  (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
  #1:  (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
  #0:  (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
  #0:  (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
  #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
  #0:  (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
  #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
  #0:  (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
  #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
  #0:  (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
  #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
  #0:  (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
  #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
  #0:  (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
  #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
  #0:  (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
  #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
  #0:  ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
  #0:  ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
  #0:  ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
  #0:  ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
  #1:  ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
  #2:  (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
  #0:  (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
  #0:  (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
  #1:  (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
  #0:  (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
  #0:  (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74

Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc997d5 ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Zubin Mithra <zsm@chromium.org>
Cc: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
netfilter: x_tables: limit allocation requests for blob rule heads 2018-04-26T09:02:21+00:00 Florian Westphal fw@strlen.de 2018-02-27T18:42:32+00:00 5bcf169444540cbb8646cb415087f5ec83f60432 commit 9d5c12a7c08f67999772065afd50fb222072114e upstream. This is a very conservative limit (134217728 rules), but good enough to not trigger frequent oom from syzkaller. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 9d5c12a7c08f67999772065afd50fb222072114e upstream.

This is a very conservative limit (134217728 rules), but good
enough to not trigger frequent oom from syzkaller.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
netfilter: compat: reject huge allocation requests 2018-04-26T09:02:21+00:00 Florian Westphal fw@strlen.de 2018-02-27T18:42:35+00:00 764f2162d97a498269c9b67607fe163692a79aa7 commit 7d7d7e02111e9a4dc9d0658597f528f815d820fd upstream. no need to bother even trying to allocating huge compat offset arrays, such ruleset is rejected later on anyway becaus we refuse to allocate overly large rule blobs. However, compat translation happens before blob allocation, so we should add a check there too. This is supposed to help with fuzzing by avoiding oom-killer. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 7d7d7e02111e9a4dc9d0658597f528f815d820fd upstream.

no need to bother even trying to allocating huge compat offset arrays,
such ruleset is rejected later on anyway becaus we refuse to allocate
overly large rule blobs.

However, compat translation happens before blob allocation, so we should
add a check there too.

This is supposed to help with fuzzing by avoiding oom-killer.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
netfilter: compat: prepare xt_compat_init_offsets to return errors 2018-04-26T09:02:21+00:00 Florian Westphal fw@strlen.de 2018-02-27T18:42:34+00:00 8d92d53365395c97cf819a10cda4693f792cd5b6 commit 9782a11efc072faaf91d4aa60e9d23553f918029 upstream. should have no impact, function still always returns 0. This patch is only to ease review. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 9782a11efc072faaf91d4aa60e9d23553f918029 upstream.

should have no impact, function still always returns 0.
This patch is only to ease review.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
netfilter: x_tables: add counters allocation wrapper 2018-04-26T09:02:21+00:00 Florian Westphal fw@strlen.de 2018-02-27T18:42:33+00:00 82b68ecde5d056588799f0d38e675bbb81fe3b46 commit c84ca954ac9fa67a6ce27f91f01e4451c74fd8f6 upstream. allows to have size checks in a single spot. This is supposed to reduce oom situations when fuzz-testing xtables. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit c84ca954ac9fa67a6ce27f91f01e4451c74fd8f6 upstream.

allows to have size checks in a single spot.
This is supposed to reduce oom situations when fuzz-testing xtables.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
netfilter: x_tables: cap allocations at 512 mbyte 2018-04-26T09:02:21+00:00 Florian Westphal fw@strlen.de 2018-02-27T18:42:31+00:00 fab0b3ce67a54f45848ee5d6023ef9a42153a2c9 commit 19926968ea86a286aa6fbea16ee3f2e7442f10f0 upstream. Arbitrary limit, however, this still allows huge rulesets (> 1 million rules). This helps with automated fuzzer as it prevents oom-killer invocation. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 19926968ea86a286aa6fbea16ee3f2e7442f10f0 upstream.

Arbitrary limit, however, this still allows huge rulesets
(> 1 million rules).  This helps with automated fuzzer as it prevents
oom-killer invocation.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
netfilter: x_tables: fix pointer leaks to userspace 2018-04-26T09:02:13+00:00 Dmitry Vyukov dvyukov@google.com 2018-01-29T12:21:20+00:00 ad10785a706e63ff155fc97860cdcc5e3bc5992d [ Upstream commit 1e98ffea5a8935ec040ab72299e349cb44b8defd ] Several netfilter matches and targets put kernel pointers into info objects, but don't set usersize in descriptors. This leads to kernel pointer leaks if a match/target is set and then read back to userspace. Properly set usersize for these matches/targets. Found with manual code inspection. Fixes: ec2318904965 ("xtables: extend matches and targets with .usersize") Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 1e98ffea5a8935ec040ab72299e349cb44b8defd ]

Several netfilter matches and targets put kernel pointers into
info objects, but don't set usersize in descriptors.
This leads to kernel pointer leaks if a match/target is set
and then read back to userspace.

Properly set usersize for these matches/targets.

Found with manual code inspection.

Fixes: ec2318904965 ("xtables: extend matches and targets with .usersize")
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
netfilter: ipset: Missing nfnl_lock()/nfnl_unlock() is added to ip_set_net_exit() 2018-04-19T06:56:15+00:00 Jozsef Kadlecsik kadlec@blackhole.kfki.hu 2018-01-06T14:24:18+00:00 073e82701bc02c18ffb01579fa2b4971149d1976 commit f998b6b10144cd9809da6af02758615f789e8aa1 upstream. Patch "netfilter: ipset: use nfnl_mutex_is_locked" is added the real mutex locking check, which revealed the missing locking in ip_set_net_exit(). Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Reported-by: syzbot+36b06f219f2439fe62e1@syzkaller.appspotmail.com Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit f998b6b10144cd9809da6af02758615f789e8aa1 upstream.

Patch "netfilter: ipset: use nfnl_mutex_is_locked" is added the real
mutex locking check, which revealed the missing locking in ip_set_net_exit().

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Reported-by: syzbot+36b06f219f2439fe62e1@syzkaller.appspotmail.com
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>