rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 ticks this GP) idle=3cec/1/0x4000000000000000 softirq=41805/41805 fqs=1 rcu: (detected by 1, t=10503 jiffies, g=66625, q=146 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4510 Comm: udevd Not tainted 6.7.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 RIP: 0010:__lock_acquire+0xca2/0x1fd0 Code: 0a 00 00 48 89 d8 48 c1 e8 03 48 89 44 24 38 80 3c 38 00 74 12 48 89 df e8 4b 4a 7d 00 48 bf 00 00 00 00 00 fc ff df 45 31 f6 <48> 89 5c 24 28 4c 8b 23 48 83 7c 24 30 00 75 30 48 c7 c0 00 f3 5c RSP: 0018:ffffc90000007950 EFLAGS: 00000046 RAX: 1ffff1100f83350e RBX: ffff88807c19a870 RCX: ffffffff816d379c RDX: 0000000000000000 RSI: 0000000000000008 RDI: dffffc0000000000 RBP: ffff88807c19a8f8 R08: ffffffff90dd7367 R09: 1ffffffff21bae6c R10: dffffc0000000000 R11: fffffbfff21bae6d R12: 0000000000000001 R13: ffff88807c199dc0 R14: 0000000000000000 R15: ffff88807c19a918 FS: 00007f3344baec80(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f816c8dbd88 CR3: 000000001a774000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 debug_object_deactivate+0xc5/0x3c0 lib/debugobjects.c:783 debug_hrtimer_deactivate kernel/time/hrtimer.c:427 [inline] debug_deactivate+0x1b/0x1f0 kernel/time/hrtimer.c:483 __run_hrtimer kernel/time/hrtimer.c:1656 [inline] __hrtimer_run_queues+0x321/0xd20 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x396/0x980 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1065 [inline] __sysvec_apic_timer_interrupt+0x104/0x3a0 arch/x86/kernel/apic/apic.c:1082 sysvec_apic_timer_interrupt+0x92/0xb0 arch/x86/kernel/apic/apic.c:1076 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194 Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 fe bb c8 f6 f6 44 24 21 02 75 4e 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 03 e5 3e f6 65 8b 05 c4 f2 e1 74 85 c0 74 3f 48 c7 04 24 0e 36 RSP: 0018:ffffc900031df980 EFLAGS: 00000206 RAX: b69077179d843200 RBX: 1ffff9200063bf34 RCX: ffffffff816d950a RDX: dffffc0000000000 RSI: ffffffff8b6aadc0 RDI: 0000000000000001 RBP: ffffc900031dfa10 R08: ffffffff90dd7367 R09: 1ffffffff21bae6c R10: dffffc0000000000 R11: fffffbfff21bae6d R12: dffffc0000000000 R13: 1ffff9200063bf30 R14: ffffc900031df9a0 R15: 0000000000000246 free_unref_page_commit+0x57d/0x1130 mm/page_alloc.c:2467 free_unref_page+0x17c/0x3f0 mm/page_alloc.c:2510 __slab_free+0x2f6/0x390 mm/slub.c:3715 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x14b/0x160 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x23/0x70 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6c/0x3c0 mm/slab.h:763 slab_alloc_node mm/slub.c:3478 [inline] slab_alloc mm/slub.c:3486 [inline] __kmem_cache_alloc_lru mm/slub.c:3493 [inline] kmem_cache_alloc+0x19e/0x2b0 mm/slub.c:3502 getname_flags+0xbc/0x4f0 fs/namei.c:140 user_path_at_empty+0x2c/0x60 fs/namei.c:2910 do_readlinkat+0x118/0x3b0 fs/stat.c:494 __do_sys_readlink fs/stat.c:527 [inline] __se_sys_readlink fs/stat.c:524 [inline] __x64_sys_readlink+0x7f/0x90 fs/stat.c:524 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x45/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7f3344717d47 Code: 73 01 c3 48 8b 0d e1 90 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 59 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d b1 90 0d 00 f7 d8 64 89 01 48 RSP: 002b:00007ffed9c81d78 EFLAGS: 00000206 ORIG_RAX: 0000000000000059 RAX: ffffffffffffffda RBX: 00007ffed9c82598 RCX: 00007f3344717d47 RDX: 0000000000000200 RSI: 00007ffed9c81d88 RDI: 00007ffed9c81f88 RBP: 0000563c90885910 R08: 0000000000000000 R09: 00007ffed9c816f8 R10: 00007ffed9dfa080 R11: 0000000000000206 R12: 00007ffed9c81d88 R13: 00007ffed9c81f88 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10501 jiffies! g66625 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:24400 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5376 [inline] __schedule+0x1961/0x4ab0 kernel/sched/core.c:6688 __schedule_loop kernel/sched/core.c:6763 [inline] schedule+0x149/0x260 kernel/sched/core.c:6778 schedule_timeout+0x1bd/0x300 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x30a/0x1500 kernel/rcu/tree.c:1631 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:1830 kthread+0x2d3/0x370 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 15414 Comm: syz-executor.4 Not tainted 6.7.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline] RIP: 0010:smp_call_function_many_cond+0x1837/0x2940 kernel/smp.c:855 Code: 89 e6 83 e6 01 31 ff e8 e7 87 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 22 84 0b 00 eb 38 f3 90 42 0f b6 04 23 <84> c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 06 84 0b 00 eb e4 44 RSP: 0018:ffffc90005e77a20 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 1ffff110173087c5 RCX: 0000000000040000 RDX: ffffc90005a09000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: ffffc90005e77c10 R08: ffffffff8182f609 R09: 1ffffffff1e0171d R10: dffffc0000000000 R11: fffffbfff1e0171e R12: dffffc0000000000 R13: ffff8880b9843e28 R14: ffff8880b993d480 R15: 0000000000000000 FS: 00007f8d3de136c0(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4c49f75198 CR3: 000000002924a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: clock_was_set+0x77b/0x830 kernel/time/hrtimer.c:976 do_settimeofday64+0x488/0x640 kernel/time/timekeeping.c:1345 __do_sys_clock_settime kernel/time/posix-timers.c:1129 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1113 [inline] __x64_sys_clock_settime+0x236/0x270 kernel/time/posix-timers.c:1113 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x45/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7f8d3d07cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8d3de130c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007f8d3d19bf80 RCX: 00007f8d3d07cae9 RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000000 RBP: 00007f8d3d0c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f8d3d19bf80 R15: 00007ffe99de3c98