xt_TCPMSS: Only works on TCP SYN packets xt_TCPMSS: Only works on TCP SYN packets INFO: task syz-executor.3:21434 blocked for more than 140 seconds. Not tainted 4.19.97-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28152 21434 8096 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x866/0x1dc0 kernel/sched/core.c:3515 schedule+0x92/0x1c0 kernel/sched/core.c:3559 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 htable_put+0x21/0x220 net/netfilter/xt_hashlimit.c:440 hashlimit_mt_destroy_v1+0x50/0x70 net/netfilter/xt_hashlimit.c:972 cleanup_match+0xde/0x170 net/ipv6/netfilter/ip6_tables.c:481 find_check_entry.isra.0+0x4da/0x9d0 net/ipv6/netfilter/ip6_tables.c:585 translate_table+0xd15/0x1860 net/ipv6/netfilter/ip6_tables.c:737 do_replace net/ipv6/netfilter/ip6_tables.c:1156 [inline] do_ip6t_set_ctl+0x2ef/0x498 net/ipv6/netfilter/ip6_tables.c:1684 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] nf_setsockopt+0x77/0xd0 net/netfilter/nf_sockopt.c:115 ipv6_setsockopt net/ipv6/ipv6_sockglue.c:938 [inline] ipv6_setsockopt+0x13e/0x170 net/ipv6/ipv6_sockglue.c:922 tcp_setsockopt net/ipv4/tcp.c:3077 [inline] tcp_setsockopt+0x8f/0xe0 net/ipv4/tcp.c:3071 sock_common_setsockopt+0x94/0xd0 net/core/sock.c:3046 __sys_setsockopt+0x17a/0x280 net/socket.c:1901 __do_sys_setsockopt net/socket.c:1912 [inline] __se_sys_setsockopt net/socket.c:1909 [inline] __x64_sys_setsockopt+0xbe/0x150 net/socket.c:1909 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45b349 Code: Bad RIP value. RSP: 002b:00007f2d6d333c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f2d6d3346d4 RCX: 000000000045b349 RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000003 RBP: 000000000075bf20 R08: 0000000000000103 R09: 0000000000000000 R10: 0000000020000dc0 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000009d7 R14: 00000000004d3f88 R15: 000000000075bf2c Showing all locks held in the system: 1 lock held by khungtaskd/1081: #0: 000000000bfd37f4 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4438 1 lock held by rsyslogd/7923: #0: 000000007c6d4013 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767 2 locks held by getty/8045: #0: 0000000002bbfa63 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000003227a0ae (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/8047: #0: 000000007bf42684 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 0000000074626244 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/8048: #0: 000000005e2cd772 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000f207265f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/8049: #0: 00000000b7a90123 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 0000000028400b7b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/8050: #0: 00000000be25094e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000b9cdd685 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/8051: #0: 00000000ee3d9be2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000b456dbbb (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/10448: #0: 0000000070d86467 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000586847a3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 1 lock held by syz-executor.1/21416: 1 lock held by syz-executor.3/21434: #0: 00000000e858c40c (hashlimit_mutex){+.+.}, at: htable_put+0x21/0x220 net/netfilter/xt_hashlimit.c:440 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1081 Comm: khungtaskd Not tainted 4.19.97-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+0x197/0x210 lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x9df/0xee0 kernel/hung_task.c:287 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 21416 Comm: syz-executor.1 Not tainted 4.19.97-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:write_comp_data+0x68/0x70 kernel/kcov.c:146 Code: 00 00 4e 8d 14 dd 28 00 00 00 4d 39 d0 72 1b 49 83 c1 01 4a 89 7c 10 e0 4a 89 74 10 e8 4a 89 54 10 f0 4a 89 4c d8 20 4c 89 08 0f 1f 80 00 00 00 00 55 40 0f b6 d6 40 0f b6 f7 31 ff 48 89 e5 RSP: 0018:ffff8880ae907d80 EFLAGS: 00000006 RAX: 0000000000000101 RBX: 000000010001a000 RCX: ffffffff815b56ec RDX: 0000000000000ed6 RSI: 0000000000000000 RDI: 0000000000000007 RBP: ffff8880ae907d88 R08: ffff888043858680 R09: ffffed1015d24741 R10: ffffed1015d24740 R11: ffff8880ae923a03 R12: 000000000010001a R13: 0000000000000004 R14: 0000000000000ed6 R15: 0000000000000140 FS: 00007f0a9b947700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000045b31f CR3: 000000009230c000 CR4: 00000000001406e0 DR0: 0000000020000040 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: __next_timer_interrupt+0x9c/0x1a0 kernel/time/timer.c:1432 collect_expired_timers kernel/time/timer.c:1601 [inline] __run_timers kernel/time/timer.c:1680 [inline] __run_timers kernel/time/timer.c:1652 [inline] run_timer_softirq+0xe88/0x16a0 kernel/time/timer.c:1697 __do_softirq+0x25c/0x921 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x180/0x1d0 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x13b/0x550 arch/x86/kernel/apic/apic.c:1094 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:893 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline] RIP: 0010:lock_is_held_type+0x17e/0x210 kernel/locking/lockdep.c:3943 Code: 00 00 00 fc ff df 41 c7 85 7c 08 00 00 00 00 00 00 48 c1 e8 03 80 3c 10 00 75 63 48 83 3d d1 dc a0 07 00 74 30 48 89 df 57 9d <0f> 1f 44 00 00 48 83 c4 08 44 89 e0 5b 41 5c 41 5d 5d c3 48 83 c4 RSP: 0018:ffff888088907778 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff11e4b79 RBX: 0000000000000286 RCX: ffff888043858f00 RDX: dffffc0000000000 RSI: ffffffff88f95be0 RDI: 0000000000000286 RBP: ffff888088907798 R08: ffff888043858680 R09: ffff888043858f20 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff888043858680 R14: ffffc9001669f000 R15: 0000000009919427 lock_is_held include/linux/lockdep.h:344 [inline] ___might_sleep+0x1f4/0x2b0 kernel/sched/core.c:6157 htable_selective_cleanup+0x22c/0x330 net/netfilter/xt_hashlimit.c:382 htable_destroy net/netfilter/xt_hashlimit.c:416 [inline] htable_put+0x176/0x220 net/netfilter/xt_hashlimit.c:443 hashlimit_mt_destroy_v1+0x50/0x70 net/netfilter/xt_hashlimit.c:972 cleanup_match+0xde/0x170 net/ipv6/netfilter/ip6_tables.c:481 find_check_entry.isra.0+0x4da/0x9d0 net/ipv6/netfilter/ip6_tables.c:585 translate_table+0xd15/0x1860 net/ipv6/netfilter/ip6_tables.c:737 do_replace net/ipv6/netfilter/ip6_tables.c:1156 [inline] do_ip6t_set_ctl+0x2ef/0x498 net/ipv6/netfilter/ip6_tables.c:1684 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] nf_setsockopt+0x77/0xd0 net/netfilter/nf_sockopt.c:115 ipv6_setsockopt net/ipv6/ipv6_sockglue.c:938 [inline] ipv6_setsockopt+0x13e/0x170 net/ipv6/ipv6_sockglue.c:922 tcp_setsockopt net/ipv4/tcp.c:3077 [inline] tcp_setsockopt+0x8f/0xe0 net/ipv4/tcp.c:3071 sock_common_setsockopt+0x94/0xd0 net/core/sock.c:3046 __sys_setsockopt+0x17a/0x280 net/socket.c:1901 __do_sys_setsockopt net/socket.c:1912 [inline] __se_sys_setsockopt net/socket.c:1909 [inline] __x64_sys_setsockopt+0xbe/0x150 net/socket.c:1909 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45b349 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f0a9b946c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f0a9b9476d4 RCX: 000000000045b349 RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000006 RBP: 000000000075bf20 R08: 0000000000000103 R09: 0000000000000000 R10: 0000000020000dc0 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000009d7 R14: 00000000004d3f88 R15: 000000000075bf2c