syzbot has found a reproducer for the following issue on: HEAD commit: 9852d85ec9d4 Linux 6.12-rc1 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1516ddd0580000 kernel config: https://syzkaller.appspot.com/x/.config?x=286b31f2cf1c36b5 dashboard link: https://syzkaller.appspot.com/bug?extid=a2de4763f84f61499210 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14271980580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1358439f980000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/da91d5641713/disk-9852d85e.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/5fc1f1ed3252/vmlinux-9852d85e.xz kernel image: https://storage.googleapis.com/syzbot-assets/5affad2001eb/bzImage-9852d85e.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+a2de4763f84f61499210@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: task kworker/0:0:8 blocked for more than 149 seconds. Not tainted 6.12.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:0 state:D stack:21392 pid:8 tgid:8 ppid:2 flags:0x00004000 Workqueue: events_power_efficient reg_check_chans_work Call Trace: <TASK> context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6824 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752 wiphy_lock include/net/cfg80211.h:6014 [inline] reg_leave_invalid_chans net/wireless/reg.c:2468 [inline] reg_check_chans_work+0x164/0xfd0 net/wireless/reg.c:2483 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Showing all locks held in the system: 1 lock held by kthreadd/2: 1 lock held by khungtaskd/30: #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720 3 locks held by kworker/u8:3/52: 5 locks held by kworker/0:2/937: 3 locks held by kworker/u8:5/1067: #0: ffff8880b863ea98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:593 #1: ffff8880b8728948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x441/0x770 kernel/sched/psi.c:989 #2: ffff8880b872a718 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x112/0x240 kernel/time/timer.c:1051 5 locks held by kworker/u8:7/3017: 2 locks held by syslogd/4667: 1 lock held by klogd/4674: 4 locks held by dhcpcd/4899: 2 locks held by getty/4991: #0: ffff888031d9a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 5 locks held by syz-executor223/5245: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5245 Comm: syz-executor223 Not tainted 6.12.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:__update_freelist_fast mm/slub.c:660 [inline] RIP: 0010:slab_update_freelist mm/slub.c:730 [inline] RIP: 0010:__slab_free+0x196/0x3d0 mm/slub.c:4432 Code: ea 48 8b 4c 24 20 4d 89 f8 e8 f6 dc ff ff 89 c3 eb 43 48 8b 5c 24 20 4c 89 f9 48 89 ea 4c 89 e0 48 8b 34 24 f0 48 0f c7 4e 20 <0f> 84 c3 00 00 00 eb 4e e8 5d 7d a9 ff 48 8b 3c 24 4c 89 e6 48 89 RSP: 0018:ffffc90003c370d0 EFLAGS: 00000242 RAX: ffff8880352399c0 RBX: ffff888035239a80 RCX: 0000000000400007 RDX: 0000000000400008 RSI: ffffea0000d48e40 RDI: ffff88801ac41780 RBP: 0000000000400008 R08: 0000000000000001 R09: ffffffff81fe9dcf R10: dffffc0000000000 R11: fffffbfff2858b07 R12: ffff8880352399c0 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000400007 FS: 000055555f9ef480(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055d74c089050 CR3: 0000000078b74000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <NMI> </NMI> <TASK> qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4086 [inline] slab_alloc_node mm/slub.c:4135 [inline] kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4142 ptlock_alloc mm/memory.c:6902 [inline] ptlock_init include/linux/mm.h:2958 [inline] pmd_ptlock_init include/linux/mm.h:3062 [inline] pagetable_pmd_ctor include/linux/mm.h:3100 [inline] pmd_alloc_one_noprof include/asm-generic/pgalloc.h:141 [inline] __pmd_alloc+0x110/0x620 mm/memory.c:6315 pmd_alloc include/linux/mm.h:2849 [inline] copy_pmd_range+0x8135/0x85f0 mm/memory.c:1235 copy_pud_range mm/memory.c:1292 [inline] copy_p4d_range mm/memory.c:1316 [inline] copy_page_range+0x99f/0xe90 mm/memory.c:1414 dup_mmap kernel/fork.c:750 [inline] dup_mm kernel/fork.c:1674 [inline] copy_mm+0x11fb/0x1f40 kernel/fork.c:1723 copy_process+0x1845/0x3d50 kernel/fork.c:2375 kernel_clone+0x226/0x8f0 kernel/fork.c:2787 __do_sys_clone kernel/fork.c:2930 [inline] __se_sys_clone kernel/fork.c:2914 [inline] __x64_sys_clone+0x258/0x2a0 kernel/fork.c:2914 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7efde123ccf3 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffda41bff68 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007efde123ccf3 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 00007ffda41bfe07 R10: 000055555f9ef750 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffda41c00a0 R14: 00007ffda41c00e0 R15: 0000000000000002 </TASK> INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.825 msecs --- If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing.
