syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P8371/1:b..l P8380/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=22517, q=206 ncpus=2)
task:syz.0.644       state:R  running task     stack:25944 pid:8380  tgid:8380  ppid:5808   task_flags:0x40004c flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6929
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
 irqentry_exit+0x36/0x90 kernel/entry/common.c:211
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:check_kcov_mode kernel/kcov.c:185 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x3b/0x70 kernel/kcov.c:217
Code: 8b 05 79 72 e4 11 a9 00 01 ff 00 74 1d f6 c4 01 74 43 a9 00 00 0f 00 75 3c a9 00 00 f0 00 75 35 8b 82 7c 16 00 00 85 c0 74 2b <8b> 82 58 16 00 00 83 f8 02 75 20 48 8b 8a 60 16 00 00 8b 92 5c 16
RSP: 0018:ffffc9000bcff770 EFLAGS: 00000246
RAX: 0000000080000000 RBX: 0000000049ef8067 RCX: ffffffff82109cbc
RDX: ffff888048812480 RSI: ffffffff82109b9e RDI: 0000000000000007
RBP: ffff88802c7b6668 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff888049ef8690
R13: 1ffff9200179fef1 R14: ffffc9000bcff968 R15: 000000000127be00
 pte_lockptr include/linux/mm.h:3032 [inline]
 __pte_offset_map_lock+0xbe/0x310 mm/pgtable-generic.c:400
 pte_offset_map_lock include/linux/mm.h:3133 [inline]
 zap_pte_range mm/memory.c:1840 [inline]
 zap_pmd_range mm/memory.c:1946 [inline]
 zap_pud_range mm/memory.c:1975 [inline]
 zap_p4d_range mm/memory.c:1996 [inline]
 unmap_page_range+0xac9/0x41b0 mm/memory.c:2017
 unmap_single_vma.constprop.0+0x153/0x240 mm/memory.c:2060
 unmap_vmas+0x218/0x470 mm/memory.c:2104
 exit_mmap+0x1b2/0xb90 mm/mmap.c:1280
 __mmput+0x12a/0x410 kernel/fork.c:1133
 mmput+0x62/0x70 kernel/fork.c:1156
 exit_mm kernel/exit.c:582 [inline]
 do_exit+0x7c7/0x2bf0 kernel/exit.c:954
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1107
 __do_sys_exit_group kernel/exit.c:1118 [inline]
 __se_sys_exit_group kernel/exit.c:1116 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1116
 x64_sys_call+0x150b/0x1730 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4b9a18efc9
RSP: 002b:00007ffc57ea7618 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4b9a18efc9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffc57ea767c R08: 0000001257ea770f R09: 00000000000927c0
R10: 0000000000004d3c R11: 0000000000000246 R12: 0000000000000082
R13: 00000000000927c0 R14: 000000000003e0c9 R15: 00007ffc57ea76d0
 </TASK>
task:syz.1.641       state:R  running task     stack:26152 pid:8371  tgid:8370  ppid:5814   task_flags:0x400140 flags:0x00080001
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6929
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
 irqentry_exit+0x36/0x90 kernel/entry/common.c:211
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872
Code: 94 08 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 12 11 e9 0e 0f 82 74 02 00 00 8b 35 8a 41 e9 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 29 94 08 12 0f 85 c7 02 00 00 48 83 c4
RSP: 0018:ffffc900100c71b8 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e3c4660 RCX: 00000000ef9d33e4
RDX: 0000000000000000 RSI: ffffffff8da05660 RDI: ffffffff8bf07040
RBP: 0000000000000002 R08: 0ac0d5affe09d4ff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:867 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
 unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 save_stack+0x160/0x1f0 mm/page_owner.c:156
 __set_page_owner+0x91/0x560 mm/page_owner.c:332
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1850
 prep_new_page mm/page_alloc.c:1858 [inline]
 get_page_from_freelist+0x10a3/0x3a30 mm/page_alloc.c:3884
 __alloc_frozen_pages_noprof+0x25f/0x2470 mm/page_alloc.c:5183
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416
 alloc_slab_page mm/slub.c:3055 [inline]
 allocate_slab mm/slub.c:3228 [inline]
 new_slab+0x24a/0x360 mm/slub.c:3282
 ___slab_alloc+0xdae/0x1a60 mm/slub.c:4651
 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4770
 __slab_alloc_node mm/slub.c:4846 [inline]
 slab_alloc_node mm/slub.c:5268 [inline]
 kmem_cache_alloc_node_noprof+0x43c/0x770 mm/slub.c:5332
 __alloc_skb+0x2b2/0x380 net/core/skbuff.c:660
 alloc_skb include/linux/skbuff.h:1383 [inline]
 nlmsg_new include/net/netlink.h:1055 [inline]
 audit_buffer_alloc kernel/audit.c:1836 [inline]
 audit_log_start+0x34e/0x950 kernel/audit.c:1955
 audit_seccomp+0x60/0x290 kernel/auditsc.c:2976
 seccomp_log kernel/seccomp.c:1048 [inline]
 __seccomp_filter+0x8a4/0x11c0 kernel/seccomp.c:1376
 __secure_computing+0x287/0x3b0 kernel/seccomp.c:1404
 syscall_trace_enter+0x89/0x240 kernel/entry/syscall-common.c:44
 syscall_enter_from_user_mode_work include/linux/entry-common.h:95 [inline]
 syscall_enter_from_user_mode include/linux/entry-common.h:125 [inline]
 do_syscall_64+0x3cd/0xfa0 arch/x86/entry/syscall_64.c:90
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb2d358efc9
RSP: 002b:00007fb2d434b0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007fb2d37e5fa8 RCX: 00007fb2d358efc9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fb2d37e5fa8
RBP: 00007fb2d37e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb2d37e6038 R14: 00007ffe2d4e2d50 R15: 00007ffe2d4e2e38
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10579 jiffies! g22517 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=14070
rcu: rcu_preempt kthread starved for 10585 jiffies! g22517 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28456 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:7026
 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 1297 Comm: aoe_tx0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 36 ca 35 f6 48 89 df e8 1e 1e 36 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 <bf> 01 00 00 00 e8 45 26 26 f6 65 8b 05 7e 65 3e 08 85 c0 74 16 5b
RSP: 0018:ffffc90004abf958 EFLAGS: 00000246
RAX: 0000000000000016 RBX: ffffffff9add9280 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff8da2b02d RDI: ffffffff8bf07040
RBP: 0000000000000293 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff9081fcd7 R11: 0000000000000001 R12: ffffffff8f05d360
R13: ffffffff9add9388 R14: 0000000000000000 R15: ffffffff9add93c0
FS:  0000000000000000(0000) GS:ffff888124b08000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000034030 CR3: 0000000052715000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 uart_port_unlock_irqrestore include/linux/serial_core.h:788 [inline]
 uart_port_unlock_deref drivers/tty/serial/serial_core.c:91 [inline]
 uart_port_unlock_deref drivers/tty/serial/serial_core.c:88 [inline]
 uart_write_room+0x2d9/0x940 drivers/tty/serial/serial_core.c:647
 tty_write_room+0x66/0x90 drivers/tty/tty_ioctl.c:69
 handle_tx+0x14f/0x630 drivers/net/caif/caif_serial.c:212
 __netdev_start_xmit include/linux/netdevice.h:5248 [inline]
 netdev_start_xmit include/linux/netdevice.h:5257 [inline]
 xmit_one net/core/dev.c:3845 [inline]
 dev_hard_start_xmit+0x97/0x740 net/core/dev.c:3861
 __dev_queue_xmit+0xa46/0x4490 net/core/dev.c:4763
 dev_queue_xmit include/linux/netdevice.h:3365 [inline]
 tx+0xcc/0x190 drivers/block/aoe/aoenet.c:62
 kthread+0x1e4/0x3e0 drivers/block/aoe/aoecmd.c:1241
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>