syzbot


INFO: rcu detected stall in sys_mlockall

Status: upstream: reported on 2024/06/12 22:29
Reported-by: syzbot+6e0494274e4be3db4f3e@syzkaller.appspotmail.com
First crash: 6d20h, last: 6d20h
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: rcu detected stall in sys_mlockall 1 49d 49d 0/3 upstream: reported on 2024/05/01 17:12
android-5-15 BUG: soft lockup in sys_mlockall 1 53d 53d 0/2 premoderation: reported on 2024/04/27 01:55

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4335/1:b..l
	(detected by 0, t=10502 jiffies, g=8857, q=184)
task:syz-executor.3  state:R  running task     stack:24280 pid: 4335 ppid:  3530 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6780
 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 fc 7c 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:ffffc900033b77c0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff92000676f04 RCX: 1ffff92000676ea4
RDX: dffffc0000000000 RSI: ffffffff8a8b3c20 RDI: ffffffff8ad8f6c0
RBP: ffffc900033b7910 R08: dffffc0000000000 R09: fffffbfff1f7f019
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000676f00
R13: dffffc0000000000 R14: ffffc900033b7820 R15: 0000000000000246
 rcu_lock_acquire+0x20/0x30 include/linux/rcupdate.h:312
 rcu_read_lock include/linux/rcupdate.h:739 [inline]
 get_mem_cgroup_from_mm+0x31/0x260 mm/memcontrol.c:986
 __mem_cgroup_charge+0x12/0x80 mm/memcontrol.c:6777
 mem_cgroup_charge include/linux/memcontrol.h:700 [inline]
 do_anonymous_page mm/memory.c:3812 [inline]
 handle_pte_fault mm/memory.c:4619 [inline]
 __handle_mm_fault mm/memory.c:4756 [inline]
 handle_mm_fault+0x2f90/0x5950 mm/memory.c:4854
 faultin_page mm/gup.c:976 [inline]
 __get_user_pages+0x4ed/0x11d0 mm/gup.c:1197
 populate_vma_page_range+0x215/0x2a0 mm/gup.c:1529
 __mm_populate+0x2a5/0x4a0 mm/gup.c:1638
 mm_populate include/linux/mm.h:2632 [inline]
 __do_sys_mlockall mm/mlock.c:799 [inline]
 __se_sys_mlockall+0x32f/0x3c0 mm/mlock.c:775
 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: 0033:0x7fcea021fea9
RSP: 002b:00007fce9ed990c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000097
RAX: ffffffffffffffda RBX: 00007fcea0356f80 RCX: 00007fcea021fea9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 00007fcea028eff4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fcea0356f80 R15: 00007ffeb6b03588
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10461 jiffies! g8857 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=2829
rcu: rcu_preempt kthread starved for 10467 jiffies! g8857 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:27192 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1f0 kernel/sched/core.c:6459
 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:300
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:109 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:570

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/12 22:28 linux-5.15.y c61bd26ae81a f815599d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_mlockall
* Struck through repros no longer work on HEAD.