kernel msg: ebtables bug: please report to author: Unknown flag for bitmask kernel msg: ebtables bug: please report to author: Unknown flag for bitmask INFO: task syz-executor4:8350 blocked for more than 140 seconds. Not tainted 4.19.0-rc8+ #65 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D23528 8350 5501 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473 schedule+0xfe/0x460 kernel/sched/core.c:3517 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x610 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0xbe/0x1d0 kernel/locking/rwsem.c:26 inode_lock_shared include/linux/fs.h:748 [inline] lookup_slow+0x49/0x80 fs/namei.c:1687 walk_component+0x92b/0x25c0 fs/namei.c:1810 lookup_last fs/namei.c:2273 [inline] path_lookupat.isra.43+0x212/0xc00 fs/namei.c:2318 filename_lookup+0x26a/0x520 fs/namei.c:2348 user_path_at_empty+0x40/0x50 fs/namei.c:2608 user_path_at include/linux/namei.h:57 [inline] path_setxattr+0xd6/0x230 fs/xattr.c:464 __do_sys_lsetxattr fs/xattr.c:491 [inline] __se_sys_lsetxattr fs/xattr.c:487 [inline] __x64_sys_lsetxattr+0xc1/0x150 fs/xattr.c:487 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: 83 c4 18 c3 e8 d8 64 00 00 48 8b 04 24 48 8b 4c 24 08 48 89 01 e8 d7 2d fc ff e8 22 7a fc ff b8 02 00 00 00 48 8d 0d 2a 60 09 <01> 87 01 8b 05 22 60 09 01 83 f8 01 0f 85 8a 00 00 00 b8 01 00 00 RSP: 002b:00007f614539ec78 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000457569 RDX: 0000000020000600 RSI: 0000000020000480 RDI: 0000000020000440 RBP: 000000000072c040 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000009 R11: 0000000000000246 R12: 00007f614539f6d4 R13: 00000000004c2736 R14: 00000000004d3930 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/965: #0: 000000005edaa9f7 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4435 1 lock held by rsyslogd/5272: #0: 000000006a831827 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5362: #0: 00000000c38a6285 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000e66876b6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5363: #0: 00000000abee1b52 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000080048b5a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5364: #0: 000000000c30f404 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000070cc7e40 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5365: #0: 0000000085a06695 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000753edaaa (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5366: #0: 0000000075605347 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000dd0d5388 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5367: #0: 0000000067b4f6e7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000007c5c9958 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5368: #0: 00000000927ba05d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000001391fc2e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by syz-executor4/8279: #0: 00000000ef9f9ee2 (sb_writers#16){.+.+}, at: sb_start_write include/linux/fs.h:1566 [inline] #0: 00000000ef9f9ee2 (sb_writers#16){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360 #1: 00000000740bdb7e (&sb->s_type->i_mutex_key#22){++++}, at: inode_lock include/linux/fs.h:738 [inline] #1: 00000000740bdb7e (&sb->s_type->i_mutex_key#22){++++}, at: do_last fs/namei.c:3321 [inline] #1: 00000000740bdb7e (&sb->s_type->i_mutex_key#22){++++}, at: path_openat+0x15c7/0x5160 fs/namei.c:3534 1 lock held by syz-executor4/8350: #0: 00000000740bdb7e (&sb->s_type->i_mutex_key#22){++++}, at: inode_lock_shared include/linux/fs.h:748 [inline] #0: 00000000740bdb7e (&sb->s_type->i_mutex_key#22){++++}, at: lookup_slow+0x49/0x80 fs/namei.c:1687 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 965 Comm: khungtaskd Not tainted 4.19.0-rc8+ #65 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+0x1c4/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.3+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x1ed 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:144 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0xb3e/0x1050 kernel/hung_task.c:265 kthread+0x35a/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57