syzbot

watchdog: BUG: soft lockup - CPU#0 stuck for 144s! [syz.6.430:7713]
Modules linked in:
irq event stamp: 18546095
hardirqs last  enabled at (18546094): [<ffffffff8b5623c4>] irqentry_exit+0x74/0x90 kernel/entry/common.c:357
hardirqs last disabled at (18546095): [<ffffffff8b560dbe>] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1049
softirqs last  enabled at (18252510): [<ffffffff8185c3fa>] __do_softirq kernel/softirq.c:613 [inline]
softirqs last  enabled at (18252510): [<ffffffff8185c3fa>] invoke_softirq kernel/softirq.c:453 [inline]
softirqs last  enabled at (18252510): [<ffffffff8185c3fa>] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
softirqs last disabled at (18252513): [<ffffffff8185c3fa>] __do_softirq kernel/softirq.c:613 [inline]
softirqs last disabled at (18252513): [<ffffffff8185c3fa>] invoke_softirq kernel/softirq.c:453 [inline]
softirqs last disabled at (18252513): [<ffffffff8185c3fa>] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
CPU: 0 UID: 0 PID: 7713 Comm: syz.6.430 Not tainted 6.15.0-rc4-syzkaller-g8259eb0e06d8 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:get_random_u32+0x4e7/0x940 drivers/char/random.c:553
Code: e3 00 02 00 00 75 7e e8 e7 02 7f fc 48 8b 5c 24 28 4d 85 ff 75 07 e8 d8 02 7f fc eb 06 e8 d1 02 7f fc fb 8b 84 24 00 01 00 00 <48> c7 44 24 40 0e 36 e0 45 42 c7 04 23 00 00 00 00 4a c7 44 23 0c
RSP: 0018:ffffc900000079c0 EFLAGS: 00000246
RAX: 00000000f776d176 RBX: 1ffff92000000f40 RCX: ffff88802dbdbc00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000007b40 R08: ffffffff8f7ed377 R09: 1ffffffff1efda6e
R10: dffffc0000000000 R11: fffffbfff1efda6f R12: dffffc0000000000
R13: 000000000000000c R14: ffff8880b8835eb0 R15: 0000000000000200
FS:  00007fd63ceb76c0(0000) GS:ffff8881260c9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1283bf6d58 CR3: 000000004b7e4000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 __get_random_u32_below+0x14/0x90 drivers/char/random.c:567
 get_random_u32_below include/linux/random.h:63 [inline]
 garp_join_timer_arm net/802/garp.c:411 [inline]
 garp_join_timer+0xd5/0x120 net/802/garp.c:425
 call_timer_fn+0x17b/0x5f0 kernel/time/timer.c:1789
 expire_timers kernel/time/timer.c:1840 [inline]
 __run_timers kernel/time/timer.c:2414 [inline]
 __run_timer_base+0x61a/0x860 kernel/time/timer.c:2426
 run_timer_base kernel/time/timer.c:2435 [inline]
 run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2445
 handle_softirqs+0x283/0x870 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline]
 sysvec_irq_work+0xa3/0xc0 arch/x86/kernel/irq_work.c:17
 </IRQ>
 <TASK>
 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:738
RIP: 0010:rcu_read_unlock_special+0x87/0x4c0 kernel/rcu/tree_plugin.h:694
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 e2 d3 cd 10 41 f7 c6 00 00 f0 00 74 49 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc90005147420 EFLAGS: 00000206
RAX: 4c1c6e7b85d2c900 RBX: 1ffff92000a28e8c RCX: 4c1c6e7b85d2c900
RDX: 0000000000000007 RSI: ffffffff8d74ad15 RDI: ffffffff8bc1d460
RBP: ffffc90005147520 R08: ffffffff8f7ed377 R09: 1ffffffff1efda6e
R10: dffffc0000000000 R11: fffffbfff1efda6f R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000246 R15: ffffffff8df40ca0
 __rcu_read_unlock+0x84/0xe0 kernel/rcu/tree_plugin.h:438
 rcu_read_unlock include/linux/rcupdate.h:873 [inline]
 d_alloc_parallel+0x1220/0x14e0 fs/dcache.c:2614
 __lookup_slow+0x116/0x3d0 fs/namei.c:1802
 lookup_slow+0x53/0x70 fs/namei.c:1834
 walk_component+0x2d2/0x400 fs/namei.c:2138
 link_path_walk+0x6d3/0xe50 fs/namei.c:2500
 path_openat+0x28c/0x3830 fs/namei.c:4035
 do_filp_open+0x1fa/0x410 fs/namei.c:4066
 do_sys_openat2+0x121/0x1c0 fs/open.c:1429
 do_sys_open fs/open.c:1444 [inline]
 __do_sys_openat fs/open.c:1460 [inline]
 __se_sys_openat fs/open.c:1455 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1455
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd63bf8d2d0
Code: 48 89 44 24 20 75 93 44 89 54 24 0c e8 49 94 02 00 44 8b 54 24 0c 89 da 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 38 44 89 c7 89 44 24 0c e8 9c 94 02 00 8b 44
RSP: 002b:00007fd63ceb6fe0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fd63bf8d2d0
RDX: 0000000000000002 RSI: 00007fd63c010d96 RDI: 00000000ffffff9c
RBP: 00007fd63c010d96 R08: 0000000000000000 R09: 7fffffffffffffff
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007fd63c1b5fa0 R15: 00007ffc5dc693f8
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 7697 Comm: syz.7.427 Not tainted 6.15.0-rc4-syzkaller-g8259eb0e06d8 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:match_held_lock+0x7b/0xc0 kernel/locking/lockdep.c:5335
Code: c7 c2 e0 06 1e 93 48 29 d0 48 c1 f8 03 48 ba 29 5c 8f c2 f5 28 5c 8f 48 0f af d0 bb 01 00 00 00 48 39 ca 74 02 31 db 89 d8 5b <41> 5e c3 cc cc cc cc cc 90 e8 27 17 5f f9 85 c0 74 22 83 3d 40 e4
RSP: 0018:ffffc90000a07b48 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000023 RCX: 77f32fedb692f000
RDX: 0000000000010100 RSI: ffffffff8df3b860 RDI: ffff8880435ee608
RBP: ffff8880435ee608 R08: ffffc90000a07817 R09: 0000000000000000
R10: ffffc90000a07808 R11: fffff52000140f03 R12: 0000000000000007
R13: 0000000000000007 R14: ffffffff8df3b860 R15: ffff8880435eda00
FS:  00007fae5ff2f6c0(0000) GS:ffff8881261c9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c356345 CR3: 000000006cdae000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 find_held_lock kernel/locking/lockdep.c:5348 [inline]
 __lock_release kernel/locking/lockdep.c:5533 [inline]
 lock_release+0x127/0x3e0 kernel/locking/lockdep.c:5887
 rcu_lock_release include/linux/rcupdate.h:341 [inline]
 rcu_read_unlock include/linux/rcupdate.h:871 [inline]
 __perf_event_output kernel/events/core.c:8364 [inline]
 perf_event_output_forward+0x37f/0x430 kernel/events/core.c:8373
 __perf_event_overflow+0x7cc/0xe10 kernel/events/core.c:10249
 perf_swevent_hrtimer+0x3c2/0x540 kernel/events/core.c:11613
 __run_hrtimer kernel/time/hrtimer.c:1761 [inline]
 __hrtimer_run_queues+0x4dd/0xc60 kernel/time/hrtimer.c:1825
 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
 __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1055
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1049
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:deref_stack_reg+0x1/0x230 arch/x86/kernel/unwind_orc.c:402
Code: 24 18 e8 32 29 b0 00 48 8b 4c 24 18 e9 f2 fe ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 <41> 57 41 56 41 55 41 54 53 48 83 ec 20 48 89 54 24 18 49 89 f0 49
RSP: 0018:ffffc90000a083c8 EFLAGS: 00000287
RAX: fffffffffffffff0 RBX: ffffffff90b342e6 RCX: 0000000000000000
RDX: ffffc90000a084e8 RSI: ffffc90004f6ff48 RDI: ffffc90000a084a8
RBP: dffffc0000000000 R08: ffffc90000a08507 R09: 0000000000000000
R10: ffffc90000a084f8 R11: fffff520001410a1 R12: ffffc90004f6ff48
R13: ffffc90000a084f8 R14: ffffc90000a084a8 R15: 1ffffffff216685d
 unwind_next_frame+0x17c4/0x2390 arch/x86/kernel/unwind_orc.c:-1
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4161 [inline]
 slab_alloc_node mm/slub.c:4210 [inline]
 kmem_cache_alloc_node_noprof+0x1bb/0x3c0 mm/slub.c:4262
 kmalloc_reserve+0xbd/0x290 net/core/skbuff.c:577
 __alloc_skb+0x142/0x2d0 net/core/skbuff.c:668
 __netdev_alloc_skb+0x108/0x970 net/core/skbuff.c:732
 netdev_alloc_skb include/linux/skbuff.h:3413 [inline]
 dev_alloc_skb include/linux/skbuff.h:3426 [inline]
 __ieee80211_beacon_get+0xe32/0x1630 net/mac80211/tx.c:5475
 ieee80211_beacon_get_tim+0xb4/0x2b0 net/mac80211/tx.c:5597
 ieee80211_beacon_get include/net/mac80211.h:5648 [inline]
 mac80211_hwsim_beacon_tx+0x3d2/0x860 drivers/net/wireless/virtual/mac80211_hwsim.c:2313
 __iterate_interfaces+0x2a8/0x590 net/mac80211/util.c:761
 ieee80211_iterate_active_interfaces_atomic+0xdb/0x180 net/mac80211/util.c:797
 mac80211_hwsim_beacon+0xbb/0x1c0 drivers/net/wireless/virtual/mac80211_hwsim.c:2347
 __run_hrtimer kernel/time/hrtimer.c:1761 [inline]
 __hrtimer_run_queues+0x529/0xc60 kernel/time/hrtimer.c:1825
 hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1842
 handle_softirqs+0x283/0x870 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:finish_task_switch+0x26b/0x950 kernel/sched/core.c:5250
Code: 0f 84 3c 01 00 00 48 85 db 0f 85 63 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 ff c3 c6 09 e8 6a 66 35 00 fb 4c 8b 65 c0 <49> 8d bc 24 18 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc90004f6f298 EFLAGS: 00000282
RAX: 77f32fedb692f000 RBX: 0000000000000000 RCX: 77f32fedb692f000
RDX: 0000000000000007 RSI: ffffffff8d74ad15 RDI: ffffffff8bc1d460
RBP: ffffc90004f6f2f0 R08: ffffffff8f7ed377 R09: 1ffffffff1efda6e
R10: dffffc0000000000 R11: fffffbfff1efda6f R12: ffff8880435eda00
R13: dffffc0000000000 R14: ffff888020bbbc00 R15: ffff8880b893a6d8
 context_switch kernel/sched/core.c:5385 [inline]
 __schedule+0x16ea/0x4cd0 kernel/sched/core.c:6767
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7090
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:qlist_free_all+0x6d/0x140 mm/kasan/quarantine.c:177
Code: e0 c0 4a 8b 4c 28 08 f6 c1 01 0f 85 ad 00 00 00 4c 01 e8 66 90 0f b6 48 33 c1 e1 18 81 f9 00 00 00 f5 48 0f 45 c5 4c 8b 60 08 <49> 8b 1f 49 63 84 24 c0 00 00 00 49 29 c7 4c 89 e7 4c 89 fe e8 9a
RSP: 0018:ffffc90004f6f698 EFLAGS: 00010246
RAX: ffffea00009c04c0 RBX: ffff888027013a20 RCX: 00000000f5000000
RDX: ffffc9000dd88000 RSI: 00000000000233ad RDI: 00000000000233ae
RBP: 0000000000000000 R08: 000000000000000a R09: ffff88807c3ca000
R10: 0000000000000000 R11: fffffbfff1efda6f R12: ffff88801a041640
R13: ffffea0000000000 R14: 0000000000000000 R15: ffff888027013a20
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4161 [inline]
 slab_alloc_node mm/slub.c:4210 [inline]
 __do_kmalloc_node mm/slub.c:4340 [inline]
 __kmalloc_node_track_caller_noprof+0x216/0x4e0 mm/slub.c:4360
 __kmemdup_nul mm/util.c:63 [inline]
 kstrdup+0x42/0x100 mm/util.c:83
 __kernfs_new_node+0x9c/0x7f0 fs/kernfs/dir.c:633
 kernfs_new_node+0x102/0x210 fs/kernfs/dir.c:713
 __kernfs_create_file+0x4b/0x2e0 fs/kernfs/file.c:1038
 cgroup_add_file kernel/cgroup/cgroup.c:4290 [inline]
 cgroup_addrm_files+0x7f2/0xb20 kernel/cgroup/cgroup.c:4344
 css_populate_dir+0x123/0x3c0 kernel/cgroup/cgroup.c:1774
 cgroup_apply_control_enable+0x63c/0xb10 kernel/cgroup/cgroup.c:3290
 cgroup_mkdir+0x9eb/0xbc0 kernel/cgroup/cgroup.c:5886
 kernfs_iop_mkdir+0x20b/0x350 fs/kernfs/dir.c:1266
 vfs_mkdir+0x303/0x510 fs/namei.c:4359
 do_mkdirat+0x247/0x590 fs/namei.c:4392
 __do_sys_mkdirat fs/namei.c:4409 [inline]
 __se_sys_mkdirat fs/namei.c:4407 [inline]
 __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4407
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fae5f18e969
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fae5ff2f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fae5f3b5fa0 RCX: 00007fae5f18e969
RDX: 00000000000001ff RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007fae5f210ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fae5f3b5fa0 R15: 00007fff9f0a6918
 </TASK>