INFO: task syz.0.45:6490 blocked for more than 143 seconds.
Not tainted syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.45 state:D stack:25768 pid:6490 tgid:6489 ppid:6241 task_flags:0x40054c flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1742/0x4c30 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
rwsem_down_write_slowpath+0x926/0x10e0 kernel/locking/rwsem.c:1185
__down_write_common kernel/locking/rwsem.c:1317 [inline]
__down_write kernel/locking/rwsem.c:1326 [inline]
down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591
mmap_write_lock include/linux/mmap_lock.h:397 [inline]
exit_mmap+0x28b/0xb30 mm/mmap.c:1288
__mmput+0x118/0x420 kernel/fork.c:1129
exit_mm+0x1da/0x2c0 kernel/exit.c:582
do_exit+0x648/0x22f0 kernel/exit.c:949
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
get_signal+0x1252/0x1300 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x217/0x300 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fbaabf8eec9
RSP: 002b:00007fbaace220e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fbaac1e5fa8 RCX: 00007fbaabf8eec9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fbaac1e5fa8
RBP: 00007fbaac1e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbaac1e6038 R14: 00007fff0429bab0 R15: 00007fff0429bb98
INFO: task syz.0.45:6490 is blocked on an rw-semaphore, but the owner is not found.
INFO: task syz.3.46:6493 blocked for more than 143 seconds.
Not tainted syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.46 state:D stack:25768 pid:6493 tgid:6492 ppid:6242 task_flags:0x40054c flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1742/0x4c30 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
rwsem_down_write_slowpath+0x926/0x10e0 kernel/locking/rwsem.c:1185
__down_write_common kernel/locking/rwsem.c:1317 [inline]
__down_write kernel/locking/rwsem.c:1326 [inline]
down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591
mmap_write_lock include/linux/mmap_lock.h:397 [inline]
exit_mmap+0x28b/0xb30 mm/mmap.c:1288
__mmput+0x118/0x420 kernel/fork.c:1129
exit_mm+0x1da/0x2c0 kernel/exit.c:582
do_exit+0x648/0x22f0 kernel/exit.c:949
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
get_signal+0x1252/0x1300 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x217/0x300 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f1bab58eec9
RSP: 002b:00007f1bac4370e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f1bab7e5fa8 RCX: 00007f1bab58eec9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f1bab7e5fa8
RBP: 00007f1bab7e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1bab7e6038 R14: 00007ffc87c274f0 R15: 00007ffc87c275d8
INFO: task syz.3.46:6493 is blocked on an rw-semaphore, but the owner is not found.
Showing all locks held in the system:
2 locks held by kworker/u8:0/12:
1 lock held by khungtaskd/30:
#0: ffffffff8db372e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8db372e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8db372e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by klogd/5082:
2 locks held by udevd/5093:
#0: ffffffff8dbeb370 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1484 [inline]
#0: ffffffff8dbeb370 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x131/0x4b0 kernel/fork.c:1537
#1: ffff888071784260 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:415 [inline]
#1: ffff888071784260 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x12d/0x1c50 mm/mmap.c:1727
2 locks held by getty/5482:
#0: ffff88802ebe70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036b62f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x5ce/0x1ab0 drivers/tty/n_tty.c:2222
1 lock held by syz-execprog/6125:
#0: ffff88801efaed60 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:415 [inline]
#0: ffff88801efaed60 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x211/0x4d0 mm/util.c:578
1 lock held by syz-executor/6135:
#0: ffff888032c7ed60 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:415 [inline]
#0: ffff888032c7ed60 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x211/0x4d0 mm/util.c:578
1 lock held by syz-executor/6241:
#0: ffff8880711b6d60 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline]
#0: ffff8880711b6d60 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288
1 lock held by syz-executor/6248:
#0: ffff888025499760 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline]
#0: ffff888025499760 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288
1 lock held by syz-executor/6254:
#0: ffff888027038ca0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline]
#0: ffff888027038ca0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288
1 lock held by syz.0.45/6490:
#0: ffff88802de01760 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline]
#0: ffff88802de01760 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288
1 lock held by rm/6491:
#0: ffff88807227c260 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:415 [inline]
#0: ffff88807227c260 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x211/0x4d0 mm/util.c:578
1 lock held by syz.3.46/6493:
#0: ffff88802de00ca0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline]
#0: ffff88802de00ca0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288
1 lock held by syz-executor/7696:
#0: ffff88803179c260 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline]
#0: ffff88803179c260 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288
1 lock held by udevd/7699:
#0: ffff888031799760 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:415 [inline]
#0: ffff888031799760 (&mm->mmap_lock){++++}-{4:4}, at: __vm_munmap+0x15c/0x3d0 mm/vma.c:3152
1 lock held by syz-executor/7710:
#0: ffff888071786d60 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline]
#0: ffff888071786d60 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288
1 lock held by syz-executor/7712:
#0: ffff88807843b7a0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline]
#0: ffff88807843b7a0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288
1 lock held by syz-executor/7714:
#0: ffff8880717837a0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline]
#0: ffff8880717837a0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288
1 lock held by syz-executor/7717:
#0: ffff88807843e2a0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline]
#0: ffff88807843e2a0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288
1 lock held by syz.1.681/7888:
#0: ffff88802703ed60 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline]
#0: ffff88802703ed60 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288
1 lock held by syz.8.680/7889:
#0: ffff88802703ace0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline]
#0: ffff88802703ace0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288
1 lock held by syz.7.649/7891:
#0: ffff88802703d7e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline]
#0: ffff88802703d7e0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288
1 lock held by syz.5.682/7892:
#0: ffff88802703c260 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline]
#0: ffff88802703c260 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288
1 lock held by syz-executor/7897:
#0: ffff88802c422ce0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline]
#0: ffff88802c422ce0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288
2 locks held by syz-executor/7901:
#0: ffffffff8dbeb370 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1484 [inline]
#0: ffffffff8dbeb370 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x131/0x4b0 kernel/fork.c:1537
#1: ffff888071af01e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:415 [inline]
#1: ffff888071af01e0 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x12d/0x1c50 mm/mmap.c:1727
2 locks held by syz-executor/7906:
#0: ffffffff8dbeb370 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1484 [inline]
#0: ffffffff8dbeb370 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x131/0x4b0 kernel/fork.c:1537
#1: ffff888071af1760 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:415 [inline]
#1: ffff888071af1760 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x12d/0x1c50 mm/mmap.c:1727
1 lock held by syz.9.744/8117:
#0: ffff888032a737a0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline]
#0: ffff888032a737a0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288
1 lock held by syz.0.749/8129:
#0: ffff888032a72ce0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline]
#0: ffff888032a72ce0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28b/0xb30 mm/mmap.c:1288
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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/0x2e0 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+0x15af/0x15f0 kernel/hung_task.c:491
kthread+0x70e/0x890 kernel/kthread.c:463
ret_from_fork+0x435/0x7c0 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: 5082 Comm: klogd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:lock_release+0x2b7/0x3d0 kernel/locking/lockdep.c:5893
Code: 4b 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 75 4e f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 49 66 78 10 <48> 3b 44 24 28 75 7c 48 83 c4 30 5b 41 5c 41 5d 41 5e 41 5f 5d c3
RSP: 0018:ffffc900030f71b0 EFLAGS: 00000206
RAX: c1c71fd8cfbca700 RBX: 0000000000000202 RCX: c1c71fd8cfbca700
RDX: 0000000000000001 RSI: ffffffff8d420dcc RDI: ffffffff8b7dac80
RBP: ffff888071422920 R08: ffffc900030f77c8 R09: 0000000000000000
R10: ffffc900030f7338 R11: fffff5200061ee69 R12: 0000000000000001
R13: 0000000000000001 R14: ffffffff8db372e0 R15: ffff888071421e00
FS: 00007fa5c0705c80(0000) GS:ffff8881267f3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000003036a000 CR4: 00000000003526f0
Call Trace:
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf7/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1395 [inline]
__free_frozen_pages+0xbaa/0xd00 mm/page_alloc.c:2895
discard_slab mm/slub.c:2758 [inline]
__put_partials+0x154/0x1a0 mm/slub.c:3223
put_cpu_partial+0x17c/0x250 mm/slub.c:3298
__slab_free+0x2d5/0x3c0 mm/slub.c:4565
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x60 mm/kasan/common.c:340
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4191 [inline]
slab_alloc_node mm/slub.c:4240 [inline]
kmem_cache_alloc_node_noprof+0x1b5/0x380 mm/slub.c:4292
__alloc_skb+0x112/0x2d0 net/core/skbuff.c:659
alloc_skb include/linux/skbuff.h:1336 [inline]
alloc_skb_with_frags+0xca/0x890 net/core/skbuff.c:6665
sock_alloc_send_pskb+0x857/0x990 net/core/sock.c:2958
unix_dgram_sendmsg+0x452/0x1840 net/unix/af_unix.c:2153
sock_sendmsg_nosec net/socket.c:714 [inline]
__sock_sendmsg+0x219/0x270 net/socket.c:729
__sys_sendto+0x3ca/0x520 net/socket.c:2228
__do_sys_sendto net/socket.c:2235 [inline]
__se_sys_sendto net/socket.c:2231 [inline]
__x64_sys_sendto+0xde/0x100 net/socket.c:2231
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x8a/0x300 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fa5c0855407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffcaa512340 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fa5c0705c80 RCX: 00007fa5c0855407
RDX: 000000000000004c RSI: 00007ffcaa512480 RDI: 0000000000000003
RBP: 00007ffcaa5128b0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffcaa5128c8
R13: 00007ffcaa512480 R14: 0000000000000031 R15: 00007ffcaa512480