syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=0d8c/1/0x4000000000000000 softirq=43089/43096 fqs=4
rcu: 	(detected by 0, t=10502 jiffies, g=39885, q=397 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 10654 Comm: modprobe Not tainted 6.13.0-rc5-syzkaller-00004-gccb98ccef0e5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:debug_spin_lock_before kernel/locking/spinlock_debug.c:87 [inline]
RIP: 0010:do_raw_spin_lock+0xce/0x370 kernel/locking/spinlock_debug.c:115
Code: 48 89 44 24 20 80 3c 10 00 74 12 4c 89 ef e8 39 38 87 00 48 ba 00 00 00 00 00 fc ff df 49 8b 45 00 65 48 8b 0c 25 80 d4 03 00 <48> 89 4c 24 28 48 39 c8 0f 84 3c 01 00 00 49 8d 5c 24 08 49 89 df
RSP: 0018:ffffc90000a18bc0 EFLAGS: 00000046
RAX: ffffffffffffffff RBX: ffff8880b872c884 RCX: ffff888020b43c00
RDX: dffffc0000000000 RSI: 1ffff92000143180 RDI: ffff8880b872c880
RBP: ffffc90000a18c90 R08: ffffffff9427188f R09: 1ffffffff284e311
R10: dffffc0000000000 R11: fffffbfff284e312 R12: ffff8880b872c880
R13: ffff8880b872c890 R14: ffffc90000a18cc0 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3473b74ba8 CR3: 0000000044594000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:120 [inline]
 _raw_spin_lock_irq+0xdf/0x120 kernel/locking/spinlock.c:170
 __run_hrtimer kernel/time/hrtimer.c:1743 [inline]
 __hrtimer_run_queues+0x670/0xd30 kernel/time/hrtimer.c:1803
 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1865
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
 __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 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:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5853
Code: 2b 00 74 08 4c 89 f7 e8 2a a0 88 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25
RSP: 0018:ffffc9000478ee20 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff920008f1dd0 RCX: ffff888020b446d8
RDX: dffffc0000000000 RSI: ffffffff8c0aaae0 RDI: ffffffff8c5edd60
RBP: ffffc9000478ef78 R08: ffffffff94271937 R09: 1ffffffff284e326
R10: dffffc0000000000 R11: fffffbfff284e327 R12: 1ffff920008f1dcc
R13: dffffc0000000000 R14: ffffc9000478ee80 R15: 0000000000000246
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 __find_get_block_slow fs/buffer.c:207 [inline]
 __find_get_block+0x2b1/0x1150 fs/buffer.c:1398
 bdev_getblk+0x33/0x670 fs/buffer.c:1425
 __getblk include/linux/buffer_head.h:380 [inline]
 sb_getblk include/linux/buffer_head.h:386 [inline]
 __ext4_get_inode_loc+0x53a/0xfb0 fs/ext4/inode.c:4440
 ext4_get_inode_loc fs/ext4/inode.c:4568 [inline]
 ext4_reserve_inode_write+0x182/0x360 fs/ext4/inode.c:5827
 __ext4_mark_inode_dirty+0x1ec/0x880 fs/ext4/inode.c:6004
 ext4_dirty_inode+0xce/0x110 fs/ext4/inode.c:6041
 __mark_inode_dirty+0x2ee/0xe90 fs/fs-writeback.c:2515
 generic_update_time fs/inode.c:2112 [inline]
 inode_update_time fs/inode.c:2125 [inline]
 touch_atime+0x413/0x690 fs/inode.c:2197
 file_accessed include/linux/fs.h:2539 [inline]
 ext4_file_mmap+0x18c/0x540 fs/ext4/file.c:816
 call_mmap include/linux/fs.h:2183 [inline]
 mmap_file mm/internal.h:124 [inline]
 __mmap_new_file_vma mm/vma.c:2291 [inline]
 __mmap_new_vma mm/vma.c:2355 [inline]
 __mmap_region+0x224e/0x2d30 mm/vma.c:2456
 mmap_region+0x1d0/0x2c0 mm/mmap.c:1348
 do_mmap+0x8f0/0x1000 mm/mmap.c:496
 vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:580
 ksys_mmap_pgoff+0x4eb/0x720 mm/mmap.c:542
 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: 0033:0x7f3473e21b74
Code: 63 08 44 89 e8 5b 41 5c 41 5d c3 41 89 ca 41 f7 c1 ff 0f 00 00 74 0c c7 05 f5 46 01 00 16 00 00 00 eb 17 b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 0c f7 d8 89 05 dc 46 01 00 48 83 c8 ff c3 0f
RSP: 002b:00007ffd5ec634c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007ffd5ec63508 RCX: 00007f3473e21b74
RDX: 0000000000000005 RSI: 000000000002c000 RDI: 00007f3473b00000
RBP: 00007ffd5ec63860 R08: 0000000000000000 R09: 0000000000002000
R10: 0000000000000812 R11: 0000000000000246 R12: 00007f3473dff570
R13: 00007ffd5ec638e8 R14: 0000000000001fd8 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 10494 jiffies! g39885 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:25784 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756
 __schedule_loop kernel/sched/core.c:6833 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6848
 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045
 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247
 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>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 7970 Comm: kworker/u8:23 Not tainted 6.13.0-rc5-syzkaller-00004-gccb98ccef0e5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:check_kcov_mode kernel/kcov.c:194 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x70 kernel/kcov.c:217
Code: 80 d4 03 00 65 8b 15 e0 60 64 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 00 74 2c 8b 91 f8 15 00 00 <83> fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc
RSP: 0018:ffffc900032c76d8 EFLAGS: 00000246
RAX: ffffffff81938eab RBX: 1ffff110170e88b9 RCX: ffff888062ae9e00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900032c78e0 R08: ffffffff81938e7a R09: 1ffffffff284e310
R10: dffffc0000000000 R11: fffffbfff284e311 R12: dffffc0000000000
R13: ffff8880b87445c8 R14: ffff8880b863f940 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe6eb7e65a0 CR3: 000000000e736000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 csd_lock_wait kernel/smp.c:340 [inline]
 smp_call_function_many_cond+0x1a0b/0x2c60 kernel/smp.c:884
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1051
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:2114 [inline]
 text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2324
 text_poke_flush arch/x86/kernel/alternative.c:2515 [inline]
 text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2522
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x136/0x260 kernel/jump_label.c:210
 static_key_enable+0x1a/0x20 kernel/jump_label.c:223
 toggle_allocation_gate+0xbc/0x260 mm/kfence/core.c:849
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa66/0x1840 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>