INFO: task syz.2.19:6014 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.19 state:D stack:24496 pid:6014 ppid:5892 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
rwsem_down_write_slowpath+0xbd2/0xfa0 kernel/locking/rwsem.c:1178
__down_write_common kernel/locking/rwsem.c:1306 [inline]
__down_write kernel/locking/rwsem.c:1315 [inline]
down_write+0x1a7/0x1f0 kernel/locking/rwsem.c:1574
mmap_write_lock include/linux/mmap_lock.h:108 [inline]
exit_mmap+0x245/0xb50 mm/mmap.c:3310
__mmput+0x118/0x3c0 kernel/fork.c:1355
exit_mm+0x1da/0x2c0 kernel/exit.c:569
do_exit+0x88e/0x23c0 kernel/exit.c:870
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
__do_sys_exit_group kernel/exit.c:1035 [inline]
__se_sys_exit_group kernel/exit.c:1033 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fdc5ab8f749
RSP: 002b:00007ffc54242688 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fdc5ab8f749
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: 000000055424277f R09: 00007fdc5adb4280
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdc5adb4280 R14: 0000000000000003 R15: 00007ffc54242740
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by kworker/u4:8/3464:
#0: ffff8880b8e3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558
#1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline]
#1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: __schedule+0x20ee/0x44d0 kernel/sched/core.c:6694
2 locks held by udevd/5135:
#0: ffffffff8cdd2190 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:657 [inline]
#0: ffffffff8cdd2190 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1692 [inline]
#0: ffffffff8cdd2190 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x268/0x1ca0 kernel/fork.c:1741
#1: ffff88807de4d720 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline]
#1: ffff88807de4d720 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:658 [inline]
#1: ffff88807de4d720 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1692 [inline]
#1: ffff88807de4d720 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x283/0x1ca0 kernel/fork.c:1741
2 locks held by getty/5523:
#0: ffff88802d5440a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
1 lock held by syz-execprog/5786:
#0: ffff88802f2d4420 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline]
#0: ffff88802f2d4420 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x168/0x400 mm/util.c:554
1 lock held by syz-executor/5788:
#0: ffff88802f2d4da0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline]
#0: ffff88802f2d4da0 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x168/0x400 mm/util.c:554
1 lock held by syz-executor/5891:
#0: ffff88807b850b20 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
#0: ffff88807b850b20 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
2 locks held by syz-executor/5900:
#0: ffffffff8cdd2190 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:657 [inline]
#0: ffffffff8cdd2190 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1692 [inline]
#0: ffffffff8cdd2190 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x268/0x1ca0 kernel/fork.c:1741
#1: ffff888023a3cda0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline]
#1: ffff888023a3cda0 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:658 [inline]
#1: ffff888023a3cda0 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1692 [inline]
#1: ffff888023a3cda0 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x283/0x1ca0 kernel/fork.c:1741
1 lock held by syz.2.19/6014:
#0: ffff888060fccda0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
#0: ffff888060fccda0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf41/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 77 Comm: kworker/u4:5 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
RIP: 0010:get_current arch/x86/include/asm/current.h:41 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:244 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x8/0x90 kernel/kcov.c:313
Code: 08 03 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 15 40 21 7e 7e 65 8b 0d 41 21 7e 7e 81 e1 00 01 ff 00 74
RSP: 0018:ffffc900022ff448 EFLAGS: 00000246
RAX: ffffffff813ab240 RBX: ffffc900022f8000 RCX: 1ffff9200045feb1
RDX: ffffffff813ab186 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffff88801f2e3c00 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000000 R12: 1ffff9200045feb2
R13: 1ffff9200045feb3 R14: ffffc900022ff618 R15: ffffc90002300000
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a72f7f5660 CR3: 000000000cb30000 CR4: 00000000003506f0
Call Trace:
on_stack arch/x86/include/asm/stacktrace.h:58 [inline]
stack_access_ok arch/x86/kernel/unwind_orc.c:393 [inline]
deref_stack_reg arch/x86/kernel/unwind_orc.c:403 [inline]
unwind_next_frame+0xf00/0x2970 arch/x86/kernel/unwind_orc.c:585
__unwind_start+0x66a/0x7e0 arch/x86/kernel/unwind_orc.c:760
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xf8/0x190 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
____kasan_kmalloc mm/kasan/common.c:374 [inline]
__kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383
kasan_kmalloc include/linux/kasan.h:198 [inline]
__do_kmalloc_node mm/slab_common.c:1007 [inline]
__kmalloc_node_track_caller+0xb2/0x230 mm/slab_common.c:1027
kmalloc_reserve+0x116/0x240 net/core/skbuff.c:584
pskb_expand_head+0x185/0x1230 net/core/skbuff.c:2103
__skb_cow include/linux/skbuff.h:3649 [inline]
skb_cow_head include/linux/skbuff.h:3683 [inline]
batadv_skb_head_push+0x166/0x200 net/batman-adv/soft-interface.c:72
batadv_send_skb_packet+0xeb/0x650 net/batman-adv/send.c:86
batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:391 [inline]
batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:419 [inline]
batadv_iv_send_outstanding_bat_ogm_packet+0x69a/0x840 net/batman-adv/bat_iv_ogm.c:1699
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293