INFO: task syz-executor.1:8243 can't die for more than 20 seconds. syz-executor.1 R running task 27664 8243 8094 0x80004006 Call Trace: INFO: task syz-executor.2:8278 can't die for more than 21 seconds. syz-executor.2 R running task 27520 8278 8096 0x80004006 Call Trace: context_switch kernel/sched/core.c:2817 [inline] __schedule+0x7d1/0x1580 kernel/sched/core.c:3444 Showing all locks held in the system: 1 lock held by khungtaskd/1043: #0: 00000000422f5bc6 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5148 1 lock held by rsyslogd/7891: #0: 00000000a0cb712c (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/7981: #0: 00000000e8d4b83f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000074572963 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7982: #0: 00000000517df272 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000006c9ecea (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7983: #0: 00000000f17a98f3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000003ce54205 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7984: #0: 000000007a5eb84a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000009323d7f3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7985: #0: 000000008061da89 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000d26688a6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7986: #0: 00000000fea844f1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000002b6a27b2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7987: #0: 000000001e368af1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000063d48d1e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.1/8243: 1 lock held by syz-executor.2/8278: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1043 Comm: khungtaskd Not tainted 5.1.0+ #1 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+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 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:224 [inline] watchdog+0xa58/0x1020 kernel/hung_task.c:308 kthread+0x357/0x430 kernel/kthread.c:253 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 140 Comm: kworker/u4:3 Not tainted 5.1.0+ #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:memory_is_nonzero mm/kasan/generic.c:108 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:135 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:166 [inline] RIP: 0010:check_memory_region_inline mm/kasan/generic.c:182 [inline] RIP: 0010:check_memory_region+0x53/0x190 mm/kasan/generic.c:191 Code: 8d 5c 37 ff 49 89 f8 48 b8 00 00 00 00 00 fc ff df 4d 89 da 49 c1 e8 03 4d 8d 24 00 49 c1 ea 03 49 01 c2 4c 89 e0 49 8d 5a 01 <49> 89 d9 4d 29 e1 49 83 f9 10 0f 8e 99 00 00 00 45 89 e0 41 83 e0 RSP: 0018:ffff8880a94efc70 EFLAGS: 00000282 RAX: ffffed1015d26bdf RBX: ffffed1015d26be0 RCX: ffffffff815ee314 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880ae935ef8 RBP: ffff8880a94efc88 R08: 1ffff11015d26bdf R09: ffff8880a94e2f78 R10: ffffed1015d26bdf R11: ffff8880ae935efb R12: ffffed1015d26bdf R13: 0000000000000328 R14: ffff88809e413380 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000001b10e00 CR3: 000000009862f000 CR4: 00000000001406e0 Call Trace: kasan_check_read+0x11/0x20 mm/kasan/common.c:94 atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] rcu_dynticks_curr_cpu_in_eqs+0x54/0xb0 kernel/rcu/tree.c:292 rcu_is_watching+0x10/0x30 kernel/rcu/tree.c:872 rcu_read_lock include/linux/rcupdate.h:596 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:407 [inline] batadv_nc_worker+0x4cd/0x760 net/batman-adv/network-coding.c:718 process_one_work+0x98e/0x1790 kernel/workqueue.c:2268 worker_thread+0x98/0xe40 kernel/workqueue.c:2414 kthread+0x357/0x430 kernel/kthread.c:253 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352