syzbot


INFO: rcu detected stall in wb_workfn (3)

Status: auto-obsoleted due to no activity on 2023/11/18 21:40
Subsystems: hfs ext4 block
[Documentation on labels]
First crash: 525d, last: 443d
Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in wb_workfn (2) fs 1 862d 862d 0/28 auto-closed as invalid on 2022/09/25 22:53
upstream INFO: rcu detected stall in wb_workfn mm 2 1105d 1112d 0/28 auto-closed as invalid on 2022/01/25 21:50
linux-4.19 INFO: rcu detected stall in wb_workfn 1 810d 810d 0/1 auto-obsoleted due to no activity on 2022/12/16 09:39
linux-5.15 INFO: rcu detected stall in wb_workfn origin:lts-only syz error 4 27d 99d 0/3 upstream: reported syz repro on 2024/07/29 15:58
linux-4.14 INFO: rcu detected stall in wb_workfn 1 1843d 1843d 0/1 auto-closed as invalid on 2020/02/17 08:22
linux-6.1 BUG: soft lockup in wb_workfn 1 12d 12d 0/3 upstream: reported on 2024/10/24 21:18

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2646 jiffies s: 10793 root: 0x2/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 13326 Comm: kworker/u4:4 Not tainted 6.5.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023
Workqueue: writeback wb_workfn (flush-7:3)
RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline]
RIP: 0010:write_comp_data+0x34/0x90 kernel/kcov.c:236
Code: 89 c6 49 89 d2 81 e6 00 01 00 00 49 89 f8 65 48 8b 14 25 80 b9 03 00 a9 00 01 ff 00 74 0e 85 f6 74 59 8b 82 04 16 00 00 85 c0 <74> 4f 8b 82 e0 15 00 00 83 f8 03 75 44 48 8b 82 e8 15 00 00 8b 92
RSP: 0018:ffffc900001e0bb8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffc9001ac79140 RCX: ffffffff88583fbc
RDX: ffff8880245cd940 RSI: 0000000000000100 RDI: 0000000000000007
RBP: ffff88807abc9b00 R08: 0000000000000007 R09: 0000000000000000
R10: fffffff0a3da8872 R11: 000000000000004e R12: fffffff0a3da8872
R13: 0000000000000000 R14: fffffff0a3da8872 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f001a07ec00 CR3: 0000000035498000 CR4: 0000000000350ee0
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 pie_calculate_probability+0x34c/0x850 net/sched/sch_pie.c:374
 fq_pie_timer+0x1da/0x4f0 net/sched/sch_fq_pie.c:387
 call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700
 expire_timers kernel/time/timer.c:1751 [inline]
 __run_timers+0x764/0xb10 kernel/time/timer.c:2022
 run_timer_softirq+0x58/0xd0 kernel/time/timer.c:2035
 __do_softirq+0x218/0x965 kernel/softirq.c:553
 invoke_softirq kernel/softirq.c:427 [inline]
 __irq_exit_rcu kernel/softirq.c:632 [inline]
 irq_exit_rcu+0xb7/0x120 kernel/softirq.c:644
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1109
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
RIP: 0010:console_flush_all+0x9b6/0xf50 kernel/printk/printk.c:2939
Code: f0 19 23 00 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 de 65 1c 00 48 85 db 0f 85 94 03 00 00 e8 40 6a 1c 00 fb 48 8b 44 24 08 <48> 8b 14 24 0f b6 00 83 e2 07 38 d0 7f 08 84 c0 0f 85 9d 04 00 00
RSP: 0018:ffffc9000a6ef488 EFLAGS: 00000293
RAX: fffff520014ddebc RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff8880245cd940 RSI: ffffffff816a0740 RDI: 0000000000000007
RBP: ffffffff8d4ca0e0 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 205d363233333154 R12: 0000000000000000
R13: ffffffff8d4ca138 R14: dffffc0000000000 R15: 0000000000000001
 console_unlock+0xc6/0x1f0 kernel/printk/printk.c:3007
 vprintk_emit+0x1c5/0x640 kernel/printk/printk.c:2307
 vprintk+0x89/0xa0 kernel/printk/printk_safe.c:50
 _printk+0xc8/0x100 kernel/printk/printk.c:2328
 hfsplus_system_write_inode fs/hfsplus/super.c:139 [inline]
 hfsplus_write_inode fs/hfsplus/super.c:162 [inline]
 hfsplus_write_inode+0x34d/0x4f0 fs/hfsplus/super.c:147
 write_inode fs/fs-writeback.c:1456 [inline]
 __writeback_single_inode+0xa81/0xe70 fs/fs-writeback.c:1668
 writeback_sb_inodes+0x599/0x1010 fs/fs-writeback.c:1894
 wb_writeback+0x2a5/0xa90 fs/fs-writeback.c:2070
 wb_do_writeback fs/fs-writeback.c:2217 [inline]
 wb_workfn+0x29c/0xfd0 fs/fs-writeback.c:2257
 process_one_work+0xaa2/0x16f0 kernel/workqueue.c:2597
 worker_thread+0x687/0x1110 kernel/workqueue.c:2748
 kthread+0x33a/0x430 kernel/kthread.c:389
 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:296
RIP: 0000:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0000:0000000000000000 EFLAGS: 00000000 ORIG_RAX: 0000000000000000
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (7731 ticks this GP) idle=3d7c/1/0x4000000000000000 softirq=47675/47677 fqs=5197
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:        4          4            0
rcu: 	cputime:      163      52315           14   ==> 52490(ms)
rcu: 	(t=10501 jiffies g=33233 q=4201 ncpus=2)
CPU: 1 PID: 13326 Comm: kworker/u4:4 Not tainted 6.5.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023
Workqueue: writeback wb_workfn (flush-7:3)
RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x33/0x70 kernel/kcov.c:207
Code: 7d 7e 89 c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b 14 25 80 b9 03 00 a9 00 01 ff 00 74 0e 85 c9 74 35 8b 82 04 16 00 00 85 c0 <74> 2b 8b 82 e0 15 00 00 83 f8 02 75 20 48 8b 8a e8 15 00 00 8b 92
RSP: 0018:ffffc900001e0bb8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00000000abcc7711 RCX: 0000000000000100
RDX: ffff8880245cd940 RSI: ffffffff88583ed6 RDI: 0000000000000007
RBP: ffff88807abc9b00 R08: 0000000000000007 R09: 00028f5c28f5c28e
R10: 0000000000000000 R11: 00000000bc172157 R12: 0000000000000064
R13: 0000000000000005 R14: 00000000112e0be8 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f001a07ec00 CR3: 000000000c776000 CR4: 0000000000350ee0
Call Trace:
 <IRQ>
 pie_calculate_probability+0x266/0x850 net/sched/sch_pie.c:347
 fq_pie_timer+0x1da/0x4f0 net/sched/sch_fq_pie.c:387
 call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700
 expire_timers kernel/time/timer.c:1751 [inline]
 __run_timers+0x764/0xb10 kernel/time/timer.c:2022
 run_timer_softirq+0x58/0xd0 kernel/time/timer.c:2035
 __do_softirq+0x218/0x965 kernel/softirq.c:553
 invoke_softirq kernel/softirq.c:427 [inline]
 __irq_exit_rcu kernel/softirq.c:632 [inline]
 irq_exit_rcu+0xb7/0x120 kernel/softirq.c:644
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1109
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
RIP: 0010:console_flush_all+0x9b6/0xf50 kernel/printk/printk.c:2939
Code: f0 19 23 00 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 de 65 1c 00 48 85 db 0f 85 94 03 00 00 e8 40 6a 1c 00 fb 48 8b 44 24 08 <48> 8b 14 24 0f b6 00 83 e2 07 38 d0 7f 08 84 c0 0f 85 9d 04 00 00
RSP: 0018:ffffc9000a6ef488 EFLAGS: 00000293
RAX: fffff520014ddebc RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff8880245cd940 RSI: ffffffff816a0740 RDI: 0000000000000007
RBP: ffffffff8d4ca0e0 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 205d353833333154 R12: 0000000000000000
R13: ffffffff8d4ca138 R14: dffffc0000000000 R15: 0000000000000001
 console_unlock+0xc6/0x1f0 kernel/printk/printk.c:3007
 vprintk_emit+0x1c5/0x640 kernel/printk/printk.c:2307
 vprintk+0x89/0xa0 kernel/printk/printk_safe.c:50
 _printk+0xc8/0x100 kernel/printk/printk.c:2328
 hfsplus_system_write_inode fs/hfsplus/super.c:139 [inline]
 hfsplus_write_inode fs/hfsplus/super.c:162 [inline]
 hfsplus_write_inode+0x34d/0x4f0 fs/hfsplus/super.c:147
 write_inode fs/fs-writeback.c:1456 [inline]
 __writeback_single_inode+0xa81/0xe70 fs/fs-writeback.c:1668
 writeback_sb_inodes+0x599/0x1010 fs/fs-writeback.c:1894
 wb_writeback+0x2a5/0xa90 fs/fs-writeback.c:2070
 wb_do_writeback fs/fs-writeback.c:2217 [inline]
 wb_workfn+0x29c/0xfd0 fs/fs-writeback.c:2257
 process_one_work+0xaa2/0x16f0 kernel/workqueue.c:2597
 worker_thread+0x687/0x1110 kernel/workqueue.c:2748
 kthread+0x33a/0x430 kernel/kthread.c:389
 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:296
RIP: 0000:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0000:0000000000000000 EFLAGS: 00000000 ORIG_RAX: 0000000000000000
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 10966 jiffies s: 10793 root: 0x2/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 13326 Comm: kworker/u4:4 Not tainted 6.5.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023
Workqueue: writeback wb_workfn (flush-7:3)
RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x33/0x70 kernel/kcov.c:207
Code: 7d 7e 89 c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b 14 25 80 b9 03 00 a9 00 01 ff 00 74 0e 85 c9 74 35 8b 82 04 16 00 00 85 c0 <74> 2b 8b 82 e0 15 00 00 83 f8 02 75 20 48 8b 8a e8 15 00 00 8b 92
RSP: 0018:ffffc900001e0bb8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffc90017ba95b0 RCX: 0000000000000100
RDX: ffff8880245cd940 RSI: ffffffff88583fdf RDI: 0000000000000006
RBP: ffff888029450300 R08: 0000000000000006 R09: 0000000000000000
R10: fffffff0a3da8872 R11: 000000000000004e R12: fffffff0a3da8872
R13: 0000000000000000 R14: fffffff0a3da8872 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000000c776000 CR4: 0000000000350ee0
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 pie_calculate_probability+0x36f/0x850 net/sched/sch_pie.c:388
 fq_pie_timer+0x1da/0x4f0 net/sched/sch_fq_pie.c:387
 call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700
 expire_timers kernel/time/timer.c:1751 [inline]
 __run_timers+0x764/0xb10 kernel/time/timer.c:2022
 run_timer_softirq+0x58/0xd0 kernel/time/timer.c:2035
 __do_softirq+0x218/0x965 kernel/softirq.c:553
 invoke_softirq kernel/softirq.c:427 [inline]
 __irq_exit_rcu kernel/softirq.c:632 [inline]
 irq_exit_rcu+0xb7/0x120 kernel/softirq.c:644
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1109
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
RIP: 0010:console_flush_all+0x9b6/0xf50 kernel/printk/printk.c:2939
Code: f0 19 23 00 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 de 65 1c 00 48 85 db 0f 85 94 03 00 00 e8 40 6a 1c 00 fb 48 8b 44 24 08 <48> 8b 14 24 0f b6 00 83 e2 07 38 d0 7f 08 84 c0 0f 85 9d 04 00 00
RSP: 0018:ffffc9000a6ef488 EFLAGS: 00000293
RAX: fffff520014ddebc RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff8880245cd940 RSI: ffffffff816a0740 RDI: 0000000000000007
RBP: ffffffff8d4ca0e0 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 205d353833333154 R12: 0000000000000000
R13: ffffffff8d4ca138 R14: dffffc0000000000 R15: 0000000000000001
 console_unlock+0xc6/0x1f0 kernel/printk/printk.c:3007
 vprintk_emit+0x1c5/0x640 kernel/printk/printk.c:2307
 vprintk+0x89/0xa0 kernel/printk/printk_safe.c:50
 _printk+0xc8/0x100 kernel/printk/printk.c:2328
 hfsplus_system_write_inode fs/hfsplus/super.c:139 [inline]
 hfsplus_write_inode fs/hfsplus/super.c:162 [inline]
 hfsplus_write_inode+0x34d/0x4f0 fs/hfsplus/super.c:147
 write_inode fs/fs-writeback.c:1456 [inline]
 __writeback_single_inode+0xa81/0xe70 fs/fs-writeback.c:1668
 writeback_sb_inodes+0x599/0x1010 fs/fs-writeback.c:1894
 wb_writeback+0x2a5/0xa90 fs/fs-writeback.c:2070
 wb_do_writeback fs/fs-writeback.c:2217 [inline]
 wb_workfn+0x29c/0xfd0 fs/fs-writeback.c:2257
 process_one_work+0xaa2/0x16f0 kernel/workqueue.c:2597
 worker_thread+0x687/0x1110 kernel/workqueue.c:2748
 kthread+0x33a/0x430 kernel/kthread.c:389
 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:296
RIP: 0000:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0000:0000000000000000 EFLAGS: 00000000 ORIG_RAX: 0000000000000000
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
NMI backtrace for cpu 1
CPU: 1 PID: 13326 Comm: kworker/u4:4 Not tainted 6.5.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023
Workqueue: writeback wb_workfn (flush-7:3)
RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x11/0x70 kernel/kcov.c:207
Code: b0 01 00 00 e8 b0 ff ff ff 31 c0 c3 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 f3 0f 1e fa 65 8b 05 fd 47 7d 7e 89 c1 48 8b 34 24 <81> e1 00 01 00 00 65 48 8b 14 25 80 b9 03 00 a9 00 01 ff 00 74 0e
RSP: 0018:ffffc900001e0bb8 EFLAGS: 00000297
RAX: 0000000000000102 RBX: ffffc9001ad4b6f0 RCX: 0000000000000102
RDX: ffff8880245cd940 RSI: ffffffff88583faa RDI: 0000000000000007
RBP: ffff88807abc9b00 R08: 0000000000000007 R09: 00000000003b9aca
R10: 0000000000000000 R11: 000000000000004e R12: fffffff0a3da8872
R13: 0000000000000000 R14: 00051eb851eb851e R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000000c776000 CR4: 0000000000350ee0
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 pie_calculate_probability+0x33a/0x850 net/sched/sch_pie.c:372
 fq_pie_timer+0x1da/0x4f0 net/sched/sch_fq_pie.c:387
 call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700
 expire_timers kernel/time/timer.c:1751 [inline]
 __run_timers+0x764/0xb10 kernel/time/timer.c:2022
 run_timer_softirq+0x58/0xd0 kernel/time/timer.c:2035
 __do_softirq+0x218/0x965 kernel/softirq.c:553
 invoke_softirq kernel/softirq.c:427 [inline]
 __irq_exit_rcu kernel/softirq.c:632 [inline]
 irq_exit_rcu+0xb7/0x120 kernel/softirq.c:644
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1109
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
RIP: 0010:console_flush_all+0x9b6/0xf50 kernel/printk/printk.c:2939
Code: f0 19 23 00 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 de 65 1c 00 48 85 db 0f 85 94 03 00 00 e8 40 6a 1c 00 fb 48 8b 44 24 08 <48> 8b 14 24 0f b6 00 83 e2 07 38 d0 7f 08 84 c0 0f 85 9d 04 00 00
RSP: 0018:ffffc9000a6ef488 EFLAGS: 00000293
RAX: fffff520014ddebc RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff8880245cd940 RSI: ffffffff816a0740 RDI: 0000000000000007
RBP: ffffffff8d4ca0e0 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 205d353833333154 R12: 0000000000000000
R13: ffffffff8d4ca138 R14: dffffc0000000000 R15: 0000000000000001
 console_unlock+0xc6/0x1f0 kernel/printk/printk.c:3007
 vprintk_emit+0x1c5/0x640 kernel/printk/printk.c:2307
 vprintk+0x89/0xa0 kernel/printk/printk_safe.c:50
 _printk+0xc8/0x100 kernel/printk/printk.c:2328
 hfsplus_system_write_inode fs/hfsplus/super.c:139 [inline]
 hfsplus_write_inode fs/hfsplus/super.c:162 [inline]
 hfsplus_write_inode+0x34d/0x4f0 fs/hfsplus/super.c:147
 write_inode fs/fs-writeback.c:1456 [inline]
 __writeback_single_inode+0xa81/0xe70 fs/fs-writeback.c:1668
 writeback_sb_inodes+0x599/0x1010 fs/fs-writeback.c:1894
 wb_writeback+0x2a5/0xa90 fs/fs-writeback.c:2070
 wb_do_writeback fs/fs-writeback.c:2217 [inline]
 wb_workfn+0x29c/0xfd0 fs/fs-writeback.c:2257
 process_one_work+0xaa2/0x16f0 kernel/workqueue.c:2597
 worker_thread+0x687/0x1110 kernel/workqueue.c:2748
 kthread+0x33a/0x430 kernel/kthread.c:389
 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:296
RIP: 0000:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0000:0000000000000000 EFLAGS: 00000000 ORIG_RAX: 0000000000000000
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/07/18 07:12 upstream fdf0eaf11452 20f8b3c2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in wb_workfn
2023/05/30 13:18 upstream 8b817fded42d 8d5c7541 .config console log report info ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in wb_workfn
2023/08/20 21:31 net-next 669a55560e4b d216d8a0 .config console log report info ci-upstream-net-kasan-gce INFO: rcu detected stall in wb_workfn
* Struck through repros no longer work on HEAD.