INFO: rcu detected stall in asm_exc_page_fault

Status: auto-obsoleted due to no activity on 2025/07/30 11:21
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+360faf5c01a5be55581d@syzkaller.appspotmail.com
First crash: 890d, last: 496d
Cause bisection: failed (error log, bisect log)
  
Fix bisection: failed (error log, bisect log)
  
▶ ▼ Discussions (2)
Title Replies (including bot) Last reply
[syzbot] Monthly input report (Aug 2024) 0 (1) 2024/08/02 07:26
[syzbot] [mm?] [input?] [usb?] INFO: rcu detected stall in asm_exc_page_fault 3 (7) 2024/03/11 10:08
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in asm_exc_page_fault (2) kasan mm 1 1 292d 292d 0/29 auto-obsoleted due to no activity on 2026/01/22 14:37
linux-5.15 INFO: rcu detected stall in asm_exc_page_fault 1 1 203d 203d 0/3 auto-obsoleted due to no activity on 2026/05/01 14:57
linux-6.6 INFO: rcu detected stall in asm_exc_page_fault 1 1 24d 24d 0/2 upstream: reported on 2026/07/19 00:59
android-5-15 BUG: soft lockup in asm_exc_page_fault 1 syz, C error 3 710d 858d 0/2 auto-obsoleted due to no activity on 2024/12/10 17:09
▶ ▼ Last patch testing requests (5)
Created Duration User Patch Repo Result
2025/07/30 10:55 25m retest repro upstream no crash log
2024/12/01 01:57 23m retest repro upstream report log
2024/08/08 07:02 19m retest repro upstream report log
2024/05/29 22:22 20m retest repro upstream report log
2024/03/20 20:07 32m retest repro upstream error
▶ ▼ Fix bisection attempts (6)
Created Duration User Patch Repo Result
2025/05/21 06:55 25m bisect fix upstream error job log
2025/04/03 04:13 4h01m bisect fix upstream OK (0) job log log
2025/03/02 22:16 2h48m bisect fix upstream OK (0) job log log
2025/01/31 17:21 2h48m bisect fix upstream OK (0) job log log
2024/09/21 19:06 4h32m bisect fix upstream OK (0) job log log
2024/08/22 00:14 3h24m bisect fix upstream OK (0) job log log

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: {
 1-....
 } 4831 jiffies s: 1849 root: 0x2/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 0 to CPUs 1:
 kthread+0x2ef/0x390 kernel/kthread.c:388
NMI backtrace for cpu 1
CPU: 1 PID: 5232 Comm: syz-executor.3 Not tainted 6.8.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
RIP: 0010:format_decode+0x546/0x1bb0
Code: 85 96 01 00 00 45 84 ff 0f 84 8d 01 00 00 48 bb 00 ff ff ff 00 ff ff ff 48 8b 44 24 20 42 0f b6 04 30 84 c0 0f 85 4d 10 00 00 <48> 8b 54 24 48 48 21 da 48 8b 44 24 28 42 0f b6 04 30 84 c0 48 8d
RSP: 0000:ffffc900001efa20 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffffff00ffffff00 RCX: ffff8880219e0000
RDX: ffff8880219e0000 RSI: 0000000000000025 RDI: 0000000000000000
RBP: ffffc900001efb10 R08: ffffffff8b57a4c8 R09: ffffffff8b57a1aa
R10: 0000000000000002 R11: ffff8880219e0000 R12: ffffffff8bab75e6
R13: ffffffff8bab75e6 R14: dffffc0000000000 R15: 0000000000000025
FS:  0000555555c82480(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f74dc087056 CR3: 0000000021bc6000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 vsnprintf+0x14f/0x1da0 lib/vsprintf.c:2776
 sprintf+0xda/0x120 lib/vsprintf.c:3028
 print_time kernel/printk/printk.c:1324 [inline]
 info_print_prefix+0x16b/0x310 kernel/printk/printk.c:1350
 record_print_text kernel/printk/printk.c:1399 [inline]
 printk_get_next_message+0x408/0xce0 kernel/printk/printk.c:2828
 console_emit_next_record kernel/printk/printk.c:2868 [inline]
 console_flush_all+0x42d/0xec0 kernel/printk/printk.c:2967
 console_unlock+0x13b/0x4d0 kernel/printk/printk.c:3036
 vprintk_emit+0x508/0x720 kernel/printk/printk.c:2303
 _printk+0xd5/0x120 kernel/printk/printk.c:2328
 printk_stack_address arch/x86/kernel/dumpstack.c:72 [inline]
 show_trace_log_lvl+0x438/0x520 arch/x86/kernel/dumpstack.c:285
 sched_show_task+0x50c/0x6d0 kernel/sched/core.c:9171
 show_state_filter+0x19e/0x270 kernel/sched/core.c:9216
 kbd_keycode drivers/tty/vt/keyboard.c:1524 [inline]
 kbd_event+0x30fa/0x4910 drivers/tty/vt/keyboard.c:1543
 input_to_handler drivers/input/input.c:132 [inline]
 input_pass_values+0x945/0x1200 drivers/input/input.c:161
 input_event_dispose drivers/input/input.c:378 [inline]
 input_handle_event drivers/input/input.c:406 [inline]
 input_repeat_key+0x3fd/0x6c0 drivers/input/input.c:2263
 call_timer_fn+0x17e/0x600 kernel/time/timer.c:1700
 expire_timers kernel/time/timer.c:1751 [inline]
 __run_timers+0x621/0x830 kernel/time/timer.c:2038
 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2051
 __do_softirq+0x2bb/0x942 kernel/softirq.c:553
 invoke_softirq kernel/softirq.c:427 [inline]
 __irq_exit_rcu+0xf1/0x1c0 kernel/softirq.c:632
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:644
 sysvec_apic_timer_interrupt+0x97/0xb0 arch/x86/kernel/apic/apic.c:1076
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:page_table_check_set+0x58/0x700 mm/page_table_check.c:109
Code: 95 ff 85 ed 0f 84 5f 03 00 00 49 bf 00 00 00 00 00 fc ff df 48 c1 e3 06 48 bd 00 00 00 00 00 ea ff ff 48 8d 3c 2b 48 89 3c 24 <e8> 33 e9 ff ff 49 89 c6 4c 8d 64 2b 08 4c 89 e5 48 c1 ed 03 42 80
RSP: 0000:ffffc90004d0f650 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 0000000001c8ae80 RCX: ffff8880219e0000
RDX: ffff8880219e0000 RSI: 0000000000000001 RDI: ffffea0001c8ae80
RBP: ffffea0000000000 R08: ffffffff81fdf590 R09: 1ffffffff1f0880d
R10: dffffc0000000000 R11: fffffbfff1f0880e R12: 0000000000000000
R13: 0000000000000001 R14: 00000000722ba025 R15: dffffc0000000000
 __page_table_check_ptes_set+0x220/0x280 mm/page_table_check.c:196
 page_table_check_ptes_set include/linux/page_table_check.h:74 [inline]
 set_ptes include/linux/pgtable.h:241 [inline]
 set_pte_range+0x885/0x8b0 mm/memory.c:4549
 filemap_map_order0_folio mm/filemap.c:3513 [inline]
 filemap_map_pages+0xee2/0x1830 mm/filemap.c:3559
 do_fault_around mm/memory.c:4716 [inline]
 do_read_fault mm/memory.c:4749 [inline]
 do_fault mm/memory.c:4888 [inline]
 do_pte_missing mm/memory.c:3745 [inline]
 handle_pte_fault mm/memory.c:5164 [inline]
 __handle_mm_fault+0x485d/0x72d0 mm/memory.c:5305
 handle_mm_fault+0x27e/0x770 mm/memory.c:5470
 do_user_addr_fault arch/x86/mm/fault.c:1355 [inline]
 handle_page_fault arch/x86/mm/fault.c:1498 [inline]
 exc_page_fault+0x456/0x870 arch/x86/mm/fault.c:1554
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570
RIP: 0033:0x7f74dc087080
Code: Unable to access opcode bytes at 0x7f74dc087056.
RSP: 002b:00007ffe028d3bb8 EFLAGS: 00010246
RAX: 00007f74dcdfb9d0 RBX: 00007f74dcdfb6c0 RCX: 00007f74dc07de67
RDX: 0000000000000003 RSI: 0000000000020000 RDI: 00007f74dcdfb6c0
RBP: 0000000000000000 R08: 00000000ffffffff R09: 0000000000000000
R10: 0000000000021000 R11: 0000000000000206 R12: 00007ffe028d3e60
R13: ffffffffffffffc0 R14: 0000000000001000 R15: 0000000000000000
 </TASK>
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:243
 </TASK>
task:kworker/u4:0    state:I stack:24400 pid:11    tgid:11    ppid:2      flags:0x00004000
Workqueue:  0x0 (events_unbound)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5400 [inline]
 __schedule+0x177f/0x49a0 kernel/sched/core.c:6727
 __schedule_loop kernel/sched/core.c:6802 [inline]
 schedule+0x149/0x260 kernel/sched/core.c:6817
 worker_thread+0xc26/0x1000 kernel/workqueue.c:2802
 kthread+0x2ef/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:243
 </TASK>
task:kworker/u4:1    state:I stack:23344 pid:12    tgid:12    ppid:2      flags:0x00004000
Workqueue:  0x0 (bat_events)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5400 [inline]
 __schedule+0x177f/0x49a0 kernel/sched/core.c:6727
 __schedule_loop kernel/sched/core.c:6802 [inline]
 schedule+0x149/0x260 kernel/sched/core.c:6817
 worker_thread+0xc26/0x1000 kernel/workqueue.c:2802
 kthread+0x2ef/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:243
 </TASK>
task:kworker/R-mm_pe state:I stack:28752 pid:13    tgid:13    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5400 [inline]
 __schedule+0x177f/0x49a0 kernel/sched/core.c:6727
 __schedule_loop kernel/sched/core.c:6802 [inline]
 schedule+0x149/0x260 kernel/sched/core.c:6817
 rescuer_thread+0xc45/0xda0 kernel/workqueue.c:2937
 kthread+0x2ef/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:243
 </TASK>
task:rcu_tasks_kthre state:I stack:27448 pid:14    tgid:14    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5400 [inline]
 __schedule+0x177f/0x49a0 kernel/sched/core.c:6727
 __schedule_loop kernel/sched/core.c:6802 [inline]
 schedule+0x149/0x260 kernel/sched/core.c:6817
 rcu_tasks_one_gp+0x7f5/0xda0 kernel/rcu/tasks.h:578
 rcu_tasks_kthread+0x186/0x1b0 kernel/rcu/tasks.h:625
 kthread+0x2ef/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:243
 </TASK>
task:rcu_tasks_trace state:I stack:27144 pid:15    tgid:15    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5400 [inline]
 __schedule+0x177f/0x49a0 kernel/sched/core.c:6727
 __schedule_loop kernel/sched/core.c:6802 [inline]
 schedule+0x149/0x260 kernel/sched/core.c:6817
 rcu_tasks_one_gp+0x7f5/0xda0 kernel/rcu/tasks.h:578
 rcu_tasks_kthread+0x186/0x1b0 kernel/rcu/tasks.h:625
 kthread+0x2ef/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:243
 </TASK>
task:ksoftirqd/0

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/03/05 13:44 upstream 90d35da658da 5fc53669 .config console log report syz [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in asm_exc_page_fault
2024/10/17 23:08 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 07b887f8236e 666f77ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in asm_exc_page_fault
2024/10/05 04:20 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 4a9fe2a8ac53 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in asm_exc_page_fault
2024/07/23 00:03 linux-next 41c196e567fb f063dfd9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in asm_exc_page_fault
* Struck through repros no longer work on HEAD.