INFO: task syz.3.1119:9403 blocked for more than 143 seconds.
Not tainted 6.16.0-rc6-next-20250718-syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.1119 state:D stack:26632 pid:9403 tgid:9403 ppid:5842 task_flags:0x40044c flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5351 [inline]
__schedule+0x1737/0x4d30 kernel/sched/core.c:6954
__schedule_loop kernel/sched/core.c:7036 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7051
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7108
rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1088
__down_read_common kernel/locking/rwsem.c:1263 [inline]
__down_read kernel/locking/rwsem.c:1276 [inline]
down_read+0x98/0x2e0 kernel/locking/rwsem.c:1541
mmap_read_lock include/linux/mmap_lock.h:412 [inline]
exit_mm+0xcc/0x2c0 kernel/exit.c:557
do_exit+0x648/0x2300 kernel/exit.c:947
do_group_exit+0x21c/0x2d0 kernel/exit.c:1100
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:40 [inline]
exit_to_user_mode_prepare include/linux/irq-entry-common.h:208 [inline]
irqentry_exit_to_user_mode+0x81/0x120 kernel/entry/common.c:73
exc_page_fault+0x9f/0xf0 arch/x86/mm/fault.c:1535
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7f6f1fb56718
RSP: 002b:00007fff44ef2218 EFLAGS: 00010206
RAX: 0000200000001140 RBX: 0000000000000004 RCX: 0030626c6c756e72
RDX: 000000000000000d RSI: 756e722f7665642f RDI: 0000200000001140
RBP: 00007f6f1fdb7ba0 R08: 00007f6f1fa00000 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000009 R12: 00007f6f1fdb5fac
R13: 00007fff44ef2310 R14: fffffffffffffffe R15: 00007fff44ef2330
Showing all locks held in the system:
5 locks held by kworker/0:0/9:
#0: ffff888021ab8948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888021ab8948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc900000e7bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc900000e7bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffff8880282f7198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#2: ffff8880282f7198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898
#3: ffff88802df70198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#3: ffff88802df70198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006
#4: ffff88802b244160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#4: ffff88802b244160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006
1 lock held by khungtaskd/31:
#0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
4 locks held by kworker/0:2/1213:
#0: ffff888021ab8948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888021ab8948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc90003e47bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc90003e47bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffff888028435198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#2: ffff888028435198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898
#3: ffff888028186198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline]
#3: ffff888028186198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006
2 locks held by getty/5605:
#0: ffff88814d2150a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
4 locks held by udevd/5972:
#0: ffff8880529f9c30 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:182
#1: ffff888033e4f888 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x55/0x3c0 fs/kernfs/file.c:154
#2: ffff88804995d2d8 (kn->active#19){++++}-{0:0}, at: kernfs_seq_start+0x75/0x3c0 fs/kernfs/file.c:155
#3: ffff888028186198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:916 [inline]
#3: ffff888028186198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
1 lock held by udevd/6079:
1 lock held by syz.3.1119/9403:
#0: ffff88805db6e2a0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:412 [inline]
#0: ffff88805db6e2a0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0xcc/0x2c0 kernel/exit.c:557
2 locks held by syz.3.1119/9404:
4 locks held by syz.5.1947/12333:
1 lock held by syz.5.1947/12350:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
watchdog+0xf93/0xfe0 kernel/hung_task.c:491
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 2225 Comm: kworker/u8:6 Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:__local_bh_disable_ip+0xe1/0x190 kernel/softirq.c:350
Code: 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 0f 85 a4 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 65 8b 05 54 2c 62 11 25 ff ff ff 7f <39> d8 75 42 48 8b 5d 08 48 89 df e8 cf 1e 19 00 85 c0 74 09 31 db
RSP: 0018:ffffc9000488f8c0 EFLAGS: 00000202
RAX: 0000000000000201 RBX: 0000000000000201 RCX: 00000000006c6716
RDX: 0000000000000000 RSI: 0000000000000201 RDI: ffffffff8b4d7867
RBP: ffffc9000488f960 R08: ffffffff8fe3cf37 R09: 1ffffffff1fc79e6
R10: dffffc0000000000 R11: fffffbfff1fc79e7 R12: 1ffff92000911f18
R13: dffffc0000000000 R14: 0000000000000246 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8881258ab000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000083c000 CR3: 000000007699a000 CR4: 00000000003526f0
Call Trace:
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:125 [inline]
_raw_spin_lock_bh+0x1c/0x50 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:356 [inline]
batadv_nc_purge_paths+0xe7/0x3b0 net/batman-adv/network-coding.c:442
batadv_nc_worker+0x369/0x610 net/batman-adv/network-coding.c:722
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245