syzbot

 sign-in | mailing list | source | docs
🐞 Open [708]
🐞 Fixed [52]
🐞 Invalid [541]
⬇ Missing Backports [55]
Kernel Health Bugs/Month Bug Lifetimes Fuzzing Crashes
💬 Send us feedback

INFO: rcu detected stall in sys_process_vm_readv (2)

Status: upstream: reported on 2024/08/08 22:49
Reported-by: syzbot+3e7932542b8010c5e435@syzkaller.appspotmail.com
First crash: 70d, last: 17d
▶ ▼ Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_process_vm_readv (2) mm 1 768d 768d 0/28 auto-obsoleted due to no activity on 2022/12/09 23:02
upstream INFO: rcu detected stall in sys_process_vm_readv (3) mm cgroups 6 302d 478d 0/28 auto-obsoleted due to no activity on 2024/03/20 00:08
linux-5.15 INFO: rcu detected stall in sys_process_vm_readv 2 329d 372d 0/3 auto-obsoleted due to no activity on 2024/03/02 07:32
linux-6.1 INFO: rcu detected stall in sys_process_vm_readv 2 89d 102d 0/3 upstream: reported on 2024/07/07 14:50
upstream INFO: rcu detected stall in sys_process_vm_readv cgroups mm 1 906d 906d 0/28 auto-closed as invalid on 2022/06/24 21:29

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4511/1:b..l
	(detected by 1, t=10502 jiffies, g=10901, q=248)
task:syz.0.165       state:R  running task     stack:25272 pid: 4511 ppid:  4202 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6777
 irqentry_exit+0x53/0x80 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:lock_acquire+0x252/0x4f0 kernel/locking/lockdep.c:5627
Code: 2b 00 74 08 4c 89 f7 e8 0c 75 67 00 f6 44 24 61 02 0f 85 84 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:ffffc900031d7280 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff9200063ae5c RCX: 1ffff9200063adfc
RDX: dffffc0000000000 RSI: ffffffff8a8b3da0 RDI: ffffffff8ad904c0
RBP: ffffc900031d73e0 R08: dffffc0000000000 R09: fffffbfff20e2419
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200063ae58
R13: dffffc0000000000 R14: ffffc900031d72e0 R15: 0000000000000246
 rcu_lock_acquire+0x20/0x30 include/linux/rcupdate.h:312
 rcu_read_lock include/linux/rcupdate.h:739 [inline]
 percpu_ref_get_many+0x15/0x110 include/linux/percpu-refcount.h:202
 percpu_ref_get include/linux/percpu-refcount.h:222 [inline]
 css_get include/linux/cgroup.h:325 [inline]
 charge_memcg+0x145/0x340 mm/memcontrol.c:6766
 __mem_cgroup_charge+0x23/0x80 mm/memcontrol.c:6798
 mem_cgroup_charge include/linux/memcontrol.h:700 [inline]
 wp_page_copy+0x3e7/0x2070 mm/memory.c:3048
 handle_pte_fault mm/memory.c:4638 [inline]
 __handle_mm_fault mm/memory.c:4755 [inline]
 handle_mm_fault+0x2a3d/0x5960 mm/memory.c:4853
 do_user_addr_fault arch/x86/mm/fault.c:1357 [inline]
 handle_page_fault arch/x86/mm/fault.c:1445 [inline]
 exc_page_fault+0x271/0x700 arch/x86/mm/fault.c:1501
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:568
RIP: 0010:copy_user_enhanced_fast_string+0xe/0x40 arch/x86/lib/copy_user_64.S:206
Code: 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 01 ca c3 0f 1f 80 00 00 00 00 0f 01 cb 83 fa 40 0f 82 70 ff ff ff 89 d1 <f3> a4 31 c0 0f 01 ca c3 66 2e 0f 1f 84 00 00 00 00 00 89 d1 83 f8
RSP: 0018:ffffc900031d7a70 EFLAGS: 00050206
RAX: ffffffff84078f01 RBX: 00000000204f2e80 RCX: 0000000000000e80
RDX: 0000000000001000 RSI: ffff88800f55e180 RDI: 00000000204f2000
RBP: ffffc900031d7cd0 R08: dffffc0000000000 R09: ffffed1001eabe00
R10: 0000000000000000 R11: dffffc0000000001 R12: 00000000204f1e80
R13: 0000000000001000 R14: ffff88800f55e000 R15: 00007ffffffff000
 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline]
 raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline]
 copyout lib/iov_iter.c:157 [inline]
 copy_page_to_iter_iovec lib/iov_iter.c:228 [inline]
 __copy_page_to_iter lib/iov_iter.c:861 [inline]
 copy_page_to_iter+0x49a/0x10d0 lib/iov_iter.c:889
 process_vm_rw_pages mm/process_vm_access.c:45 [inline]
 process_vm_rw_single_vec mm/process_vm_access.c:117 [inline]
 process_vm_rw_core mm/process_vm_access.c:215 [inline]
 process_vm_rw+0x886/0xcc0 mm/process_vm_access.c:283
 __do_sys_process_vm_readv mm/process_vm_access.c:295 [inline]
 __se_sys_process_vm_readv mm/process_vm_access.c:291 [inline]
 __x64_sys_process_vm_readv+0xdc/0xf0 mm/process_vm_access.c:291
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f949a880ff9
RSP: 002b:00007f9498cf9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000136
RAX: ffffffffffffffda RBX: 00007f949aa38f80 RCX: 00007f949a880ff9
RDX: 0000000000000002 RSI: 0000000020008400 RDI: 0000000000000009
RBP: 00007f949a8f3296 R08: 0000000000000286 R09: 0000000000000000
R10: 0000000020008640 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f949aa38f80 R15: 00007ffe163751d8
 </TASK>
rcu: rcu_preempt kthread starved for 10478 jiffies! g10901 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:27064 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1f0 kernel/sched/core.c:6456
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:108 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:562

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/10/01 01:57 linux-5.15.y 3a5928702e71 bbd4e0a4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_process_vm_readv
2024/09/05 19:37 linux-5.15.y 14e468424d3e 464ac2ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_process_vm_readv
2024/08/18 10:27 linux-5.15.y 7e89efd3ae1c dbc93b08 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_process_vm_readv
2024/08/08 22:49 linux-5.15.y 7e89efd3ae1c 61405512 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_process_vm_readv
* Struck through repros no longer work on HEAD.