[v5.15] INFO: task hung in ip6mr_sk_done (2)
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syzbot
Jun 3, 2026, 2:15:28 PM (14 hours ago) Jun 3
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: dc027a595035 Linux 5.15.209
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=141aaf2e580000
kernel config: https://syzkaller.appspot.com/x/.config?x=353ae28c40b35af5
dashboard link: https://syzkaller.appspot.com/bug?extid=b89d107ae9a69cd06f9e
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/586ac2a2fd9d/disk-dc027a59.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/06dcb6a2fcd3/vmlinux-dc027a59.xz
kernel image: https://storage.googleapis.com/syzbot-assets/567131e0cbcc/bzImage-dc027a59.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b89d10...@syzkaller.appspotmail.com
INFO: task dhcpcd:3854 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:dhcpcd state:D stack:21168 pid: 3854 ppid: 3853 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
__mutex_lock_common+0xcfc/0x2400 kernel/locking/mutex.c:669
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
ip6mr_sk_done+0xaa/0x2b0 net/ipv6/ip6mr.c:1584
rawv6_close+0x62/0x90 net/ipv6/raw.c:1206
inet_release+0x139/0x180 net/ipv4/af_inet.c:432
__sock_release net/socket.c:651 [inline]
sock_close+0xd5/0x240 net/socket.c:1345
__fput+0x234/0x930 fs/file_table.c:311
task_work_run+0x125/0x1a0 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0x626/0x20c0 kernel/exit.c:884
do_group_exit+0x12e/0x300 kernel/exit.c:998
get_signal+0x6d6/0x12d0 kernel/signal.c:2900
arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:320
exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1499
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0033:0x7fcda14e9428
RSP: 002b:00007ffef7e13000 EFLAGS: 00010202
RAX: 0000000000000014 RBX: 00007ffef7e13080 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 00007ffef7e13080 RDI: 0000000000000040
RBP: 00007ffef7e13064 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffef7e33970
R13: 00007ffef7e13070 R14: 00007ffef7e13160 R15: 00007ffef7e23740
</TASK>
Showing all locks held in the system:
1 lock held by init/1:
#0: ffff88802cbd0f28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88802cbd0f28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
1 lock held by khungtaskd/27:
#0: ffffffff8c31f360 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kswapd0/255:
3 locks held by kworker/0:3/2857:
#0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
#1: ffffc9000d047d00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
#2: ffffffff8d43e4c8 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:74
1 lock held by jbd2/sda1-8/3523:
#0: ffffffff8c3b03e8 (oom_lock){+.+.}-{3:3}, at: __alloc_pages_may_oom mm/page_alloc.c:4308 [inline]
#0: ffffffff8c3b03e8 (oom_lock){+.+.}-{3:3}, at: __alloc_pages_slowpath+0x1d0c/0x28b0 mm/page_alloc.c:5177
2 locks held by udevd/3561:
#0: ffff88807dee4728 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88807dee4728 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
2 locks held by dhcpcd/3854:
#0: ffff88807639a610 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
#0: ffff88807639a610 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:650 [inline]
#0: ffff88807639a610 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1345
#1: ffffffff8d43e4c8 (rtnl_mutex){+.+.}-{3:3}, at: ip6mr_sk_done+0xaa/0x2b0 net/ipv6/ip6mr.c:1584
2 locks held by getty/3948:
#0: ffff88802c9c3098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc900025ce2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158
2 locks held by dhcpcd/3987:
#0: ffff88802cbd4e28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88802cbd4e28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
1 lock held by dhcpcd/3990:
#0: ffff88807a7fb928 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88807a7fb928 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
2 locks held by dhcpcd/4023:
#0: ffff888025772b28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff888025772b28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
2 locks held by sshd-session/4173:
#0: ffff88807e66f828 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88807e66f828 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
2 locks held by syz-executor/4174:
#0: ffff888024550828 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff888024550828 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
2 locks held by kworker/u4:12/4381:
#0: ffff8880b913a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
#1: ffff8880b9127888 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x4fe/0x7d0 kernel/sched/psi.c:891
3 locks held by dhcpcd/4974:
2 locks held by dhcpcd/5084:
2 locks held by dhcpcd/5242:
#0: ffff88802c755528 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88802c755528 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
2 locks held by dhcpcd/5319:
2 locks held by dhcpcd/5511:
2 locks held by dhcpcd/7103:
2 locks held by dhcpcd/7114:
2 locks held by dhcpcd/7159:
1 lock held by dhcpcd/7187:
#0: ffff88807e97ce28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88807e97ce28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
2 locks held by dhcpcd/7190:
#0: ffff88807e97c028 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88807e97c028 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
3 locks held by kworker/1:1/7978:
2 locks held by syz.4.1357/9598:
#0: ffff88807ab9c120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline]
#0: ffff88807ab9c120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_setsockopt+0x7f3/0x1af0 net/packet/af_packet.c:3830
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
5 locks held by kworker/u4:7/10387:
#0: ffff888016dcd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
#1: ffffc9000599fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
#2: ffffffff8d432590 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x148/0xba0 net/core/net_namespace.c:589
#3: ffffffff8d43e4c8 (rtnl_mutex){+.+.}-{3:3}, at: ip6_tnl_exit_batch_net+0xc8/0x620 net/ipv6/ip6_tunnel.c:2325
#4: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#4: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#4: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
2 locks held by dhcpcd/10695:
#0: ffff88802c95a428 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88802c95a428 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
2 locks held by dhcpcd/10713:
#0: ffff88807e66d528 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88807e66d528 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
2 locks held by dhcpcd/10724:
#0: ffff88801e9b1d28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88801e9b1d28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
2 locks held by dhcpcd/10726:
#0: ffff88801e9b1628 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88801e9b1628 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
2 locks held by dhcpcd/10760:
#0: ffff88807e66b228 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88807e66b228 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
1 lock held by dhcpcd/10799:
#0: ffff88807e979628 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88807e979628 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
2 locks held by dhcpcd/10801:
#0: ffff888025775528 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff888025775528 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
2 locks held by syz-executor/11825:
#0: ffff88807e668128 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88807e668128 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
2 locks held by syz-executor/11851:
#0: ffff88807a7fdc28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88807a7fdc28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
2 locks held by syz-executor/11855:
#0: ffff88807a7fb228 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88807a7fb228 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
3 locks held by kworker/0:8/11860:
#0: ffff88802b0c7938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
#1: ffffc90002f3fd00 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
#2: ffffffff8d43e4c8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4654
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
<TASK>
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xe0f/0xe50 kernel/hung_task.c:369
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 7978 Comm: kworker/1:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events_power_efficient gc_worker
RIP: 0010:check_preemption_disabled+0x18/0x110 lib/smp_processor_id.c:14
Code: 00 cc 48 c7 c7 60 09 7a 8a 48 c7 c6 a0 09 7a 8a eb 00 55 41 57 41 56 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 <65> 8b 05 f9 8a 44 76 65 8b 0d 62 e5 44 76 f7 c1 ff ff ff 7f 74 1f
RSP: 0000:ffffc9000312f940 EFLAGS: 00000082
RAX: f95bb5e5c1dbfb00 RBX: ffff88801e7e5940 RCX: ffff88801e7e5940
RDX: 0000000000000000 RSI: ffffffff8a2b3f80 RDI: ffffffff8a7a09c0
RBP: 00000000ffffffff R08: ffffffff8d8a06ef R09: 1ffffffff1b140dd
R10: dffffc0000000000 R11: fffffbfff1b140de R12: dffffc0000000000
R13: 0000000000000246 R14: ffffffff8c31f420 R15: 00000000ffffffff
FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a2f2aed186 CR3: 000000019ae96000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
lockdep_recursion_inc kernel/locking/lockdep.c:431 [inline]
lock_is_held_type+0x75/0x190 kernel/locking/lockdep.c:5665
lock_is_held include/linux/lockdep.h:287 [inline]
___might_sleep+0xea/0x610 kernel/sched/core.c:9624
gc_worker+0xc38/0x1390 net/netfilter/nf_conntrack_core.c:1544
process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
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If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
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If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
syzbot found the following issue on:
HEAD commit: dc027a595035 Linux 5.15.209
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=141aaf2e580000
kernel config: https://syzkaller.appspot.com/x/.config?x=353ae28c40b35af5
dashboard link: https://syzkaller.appspot.com/bug?extid=b89d107ae9a69cd06f9e
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/586ac2a2fd9d/disk-dc027a59.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/06dcb6a2fcd3/vmlinux-dc027a59.xz
kernel image: https://storage.googleapis.com/syzbot-assets/567131e0cbcc/bzImage-dc027a59.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b89d10...@syzkaller.appspotmail.com
INFO: task dhcpcd:3854 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:dhcpcd state:D stack:21168 pid: 3854 ppid: 3853 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
__mutex_lock_common+0xcfc/0x2400 kernel/locking/mutex.c:669
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
ip6mr_sk_done+0xaa/0x2b0 net/ipv6/ip6mr.c:1584
rawv6_close+0x62/0x90 net/ipv6/raw.c:1206
inet_release+0x139/0x180 net/ipv4/af_inet.c:432
__sock_release net/socket.c:651 [inline]
sock_close+0xd5/0x240 net/socket.c:1345
__fput+0x234/0x930 fs/file_table.c:311
task_work_run+0x125/0x1a0 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0x626/0x20c0 kernel/exit.c:884
do_group_exit+0x12e/0x300 kernel/exit.c:998
get_signal+0x6d6/0x12d0 kernel/signal.c:2900
arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:320
exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1499
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0033:0x7fcda14e9428
RSP: 002b:00007ffef7e13000 EFLAGS: 00010202
RAX: 0000000000000014 RBX: 00007ffef7e13080 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 00007ffef7e13080 RDI: 0000000000000040
RBP: 00007ffef7e13064 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffef7e33970
R13: 00007ffef7e13070 R14: 00007ffef7e13160 R15: 00007ffef7e23740
</TASK>
Showing all locks held in the system:
1 lock held by init/1:
#0: ffff88802cbd0f28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88802cbd0f28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
1 lock held by khungtaskd/27:
#0: ffffffff8c31f360 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kswapd0/255:
3 locks held by kworker/0:3/2857:
#0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
#1: ffffc9000d047d00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
#2: ffffffff8d43e4c8 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:74
1 lock held by jbd2/sda1-8/3523:
#0: ffffffff8c3b03e8 (oom_lock){+.+.}-{3:3}, at: __alloc_pages_may_oom mm/page_alloc.c:4308 [inline]
#0: ffffffff8c3b03e8 (oom_lock){+.+.}-{3:3}, at: __alloc_pages_slowpath+0x1d0c/0x28b0 mm/page_alloc.c:5177
2 locks held by udevd/3561:
#0: ffff88807dee4728 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88807dee4728 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
2 locks held by dhcpcd/3854:
#0: ffff88807639a610 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
#0: ffff88807639a610 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:650 [inline]
#0: ffff88807639a610 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1345
#1: ffffffff8d43e4c8 (rtnl_mutex){+.+.}-{3:3}, at: ip6mr_sk_done+0xaa/0x2b0 net/ipv6/ip6mr.c:1584
2 locks held by getty/3948:
#0: ffff88802c9c3098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc900025ce2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158
2 locks held by dhcpcd/3987:
#0: ffff88802cbd4e28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88802cbd4e28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
1 lock held by dhcpcd/3990:
#0: ffff88807a7fb928 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88807a7fb928 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
2 locks held by dhcpcd/4023:
#0: ffff888025772b28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff888025772b28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
2 locks held by sshd-session/4173:
#0: ffff88807e66f828 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88807e66f828 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
2 locks held by syz-executor/4174:
#0: ffff888024550828 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff888024550828 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
2 locks held by kworker/u4:12/4381:
#0: ffff8880b913a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
#1: ffff8880b9127888 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x4fe/0x7d0 kernel/sched/psi.c:891
3 locks held by dhcpcd/4974:
2 locks held by dhcpcd/5084:
2 locks held by dhcpcd/5242:
#0: ffff88802c755528 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88802c755528 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
2 locks held by dhcpcd/5319:
2 locks held by dhcpcd/5511:
2 locks held by dhcpcd/7103:
2 locks held by dhcpcd/7114:
2 locks held by dhcpcd/7159:
1 lock held by dhcpcd/7187:
#0: ffff88807e97ce28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88807e97ce28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
2 locks held by dhcpcd/7190:
#0: ffff88807e97c028 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88807e97c028 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
3 locks held by kworker/1:1/7978:
2 locks held by syz.4.1357/9598:
#0: ffff88807ab9c120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline]
#0: ffff88807ab9c120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_setsockopt+0x7f3/0x1af0 net/packet/af_packet.c:3830
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
5 locks held by kworker/u4:7/10387:
#0: ffff888016dcd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
#1: ffffc9000599fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
#2: ffffffff8d432590 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x148/0xba0 net/core/net_namespace.c:589
#3: ffffffff8d43e4c8 (rtnl_mutex){+.+.}-{3:3}, at: ip6_tnl_exit_batch_net+0xc8/0x620 net/ipv6/ip6_tunnel.c:2325
#4: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#4: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#4: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
2 locks held by dhcpcd/10695:
#0: ffff88802c95a428 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88802c95a428 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
2 locks held by dhcpcd/10713:
#0: ffff88807e66d528 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88807e66d528 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
2 locks held by dhcpcd/10724:
#0: ffff88801e9b1d28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88801e9b1d28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
2 locks held by dhcpcd/10726:
#0: ffff88801e9b1628 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88801e9b1628 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
2 locks held by dhcpcd/10760:
#0: ffff88807e66b228 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88807e66b228 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
1 lock held by dhcpcd/10799:
#0: ffff88807e979628 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88807e979628 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
2 locks held by dhcpcd/10801:
#0: ffff888025775528 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff888025775528 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
2 locks held by syz-executor/11825:
#0: ffff88807e668128 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88807e668128 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
2 locks held by syz-executor/11851:
#0: ffff88807a7fdc28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88807a7fdc28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
2 locks held by syz-executor/11855:
#0: ffff88807a7fb228 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff88807a7fb228 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1296
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
#1: ffffffff8c3df180 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x10e8/0x28b0 mm/page_alloc.c:5128
3 locks held by kworker/0:8/11860:
#0: ffff88802b0c7938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
#1: ffffc90002f3fd00 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
#2: ffffffff8d43e4c8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4654
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
<TASK>
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xe0f/0xe50 kernel/hung_task.c:369
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 7978 Comm: kworker/1:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events_power_efficient gc_worker
RIP: 0010:check_preemption_disabled+0x18/0x110 lib/smp_processor_id.c:14
Code: 00 cc 48 c7 c7 60 09 7a 8a 48 c7 c6 a0 09 7a 8a eb 00 55 41 57 41 56 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 <65> 8b 05 f9 8a 44 76 65 8b 0d 62 e5 44 76 f7 c1 ff ff ff 7f 74 1f
RSP: 0000:ffffc9000312f940 EFLAGS: 00000082
RAX: f95bb5e5c1dbfb00 RBX: ffff88801e7e5940 RCX: ffff88801e7e5940
RDX: 0000000000000000 RSI: ffffffff8a2b3f80 RDI: ffffffff8a7a09c0
RBP: 00000000ffffffff R08: ffffffff8d8a06ef R09: 1ffffffff1b140dd
R10: dffffc0000000000 R11: fffffbfff1b140de R12: dffffc0000000000
R13: 0000000000000246 R14: ffffffff8c31f420 R15: 00000000ffffffff
FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a2f2aed186 CR3: 000000019ae96000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
lockdep_recursion_inc kernel/locking/lockdep.c:431 [inline]
lock_is_held_type+0x75/0x190 kernel/locking/lockdep.c:5665
lock_is_held include/linux/lockdep.h:287 [inline]
___might_sleep+0xea/0x610 kernel/sched/core.c:9624
gc_worker+0xc38/0x1390 net/netfilter/nf_conntrack_core.c:1544
process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
---
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