Extracting prog: 3m56.894132527s
Minimizing prog: 1h6m13.63469304s
Simplifying prog options: 8m48.356471603s
Extracting C: 2m31.768841855s
Simplifying C: 0s
extracting reproducer from 50 programs
testing a last program of every proc
single: executing 11 programs separately with timeout 6m0s
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): bpf$BPF_RAW_TRACEPOINT_OPEN-prlimit64-sched_setscheduler-timer_create-timer_settime-syz_clone
detailed listing:
executing program 0:
bpf$BPF_RAW_TRACEPOINT_OPEN(0x11, 0x0, 0x0)
prlimit64(0x0, 0xe, &(0x7f0000000140)={0x8, 0x87}, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000040)=0x7)
timer_create(0x0, &(0x7f00000000c0)={0x0, 0x21}, &(0x7f0000000040))
timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
syz_clone(0x0, 0x0, 0x0, 0x0, 0x0, 0x0)
program crashed: INFO: rcu detected stall in corrupted
single: successfully extracted reproducer
found reproducer with 6 syscalls
minimizing guilty program
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): bpf$BPF_RAW_TRACEPOINT_OPEN-prlimit64-sched_setscheduler-timer_create-timer_settime
detailed listing:
executing program 0:
bpf$BPF_RAW_TRACEPOINT_OPEN(0x11, 0x0, 0x0)
prlimit64(0x0, 0xe, &(0x7f0000000140)={0x8, 0x87}, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000040)=0x7)
timer_create(0x0, &(0x7f00000000c0)={0x0, 0x21}, &(0x7f0000000040))
timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
program crashed: INFO: rcu detected stall in corrupted
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): bpf$BPF_RAW_TRACEPOINT_OPEN-prlimit64-sched_setscheduler-timer_create
detailed listing:
executing program 0:
bpf$BPF_RAW_TRACEPOINT_OPEN(0x11, 0x0, 0x0)
prlimit64(0x0, 0xe, &(0x7f0000000140)={0x8, 0x87}, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000040)=0x7)
timer_create(0x0, &(0x7f00000000c0)={0x0, 0x21}, &(0x7f0000000040))
program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): bpf$BPF_RAW_TRACEPOINT_OPEN-prlimit64-sched_setscheduler-timer_settime
detailed listing:
executing program 0:
bpf$BPF_RAW_TRACEPOINT_OPEN(0x11, 0x0, 0x0)
prlimit64(0x0, 0xe, &(0x7f0000000140)={0x8, 0x87}, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000040)=0x7)
timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): bpf$BPF_RAW_TRACEPOINT_OPEN-prlimit64-timer_create-timer_settime
detailed listing:
executing program 0:
bpf$BPF_RAW_TRACEPOINT_OPEN(0x11, 0x0, 0x0)
prlimit64(0x0, 0xe, &(0x7f0000000140)={0x8, 0x87}, 0x0)
timer_create(0x0, &(0x7f00000000c0)={0x0, 0x21}, &(0x7f0000000040))
timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): bpf$BPF_RAW_TRACEPOINT_OPEN-sched_setscheduler-timer_create-timer_settime
detailed listing:
executing program 0:
bpf$BPF_RAW_TRACEPOINT_OPEN(0x11, 0x0, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000040)=0x7)
timer_create(0x0, &(0x7f00000000c0)={0x0, 0x21}, &(0x7f0000000040))
timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_create-timer_settime
detailed listing:
executing program 0:
prlimit64(0x0, 0xe, &(0x7f0000000140)={0x8, 0x87}, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000040)=0x7)
timer_create(0x0, &(0x7f00000000c0)={0x0, 0x21}, &(0x7f0000000040))
timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
program crashed: INFO: rcu detected stall in corrupted
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_create-timer_settime
detailed listing:
executing program 0:
prlimit64(0x0, 0xe, 0x0, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000040)=0x7)
timer_create(0x0, &(0x7f00000000c0)={0x0, 0x21}, &(0x7f0000000040))
timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_create-timer_settime
detailed listing:
executing program 0:
prlimit64(0x0, 0xe, &(0x7f0000000140)={0x8, 0x87}, 0x0)
sched_setscheduler(0x0, 0x1, 0x0)
timer_create(0x0, &(0x7f00000000c0)={0x0, 0x21}, &(0x7f0000000040))
timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_create-timer_settime
detailed listing:
executing program 0:
prlimit64(0x0, 0xe, &(0x7f0000000140)={0x8, 0x87}, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000040)=0x7)
timer_create(0x0, 0x0, &(0x7f0000000040))
timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_create-timer_settime
detailed listing:
executing program 0:
prlimit64(0x0, 0xe, &(0x7f0000000140)={0x8, 0x87}, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000040)=0x7)
timer_create(0x0, &(0x7f00000000c0)={0x0, 0x21}, 0x0)
timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_create-timer_settime
detailed listing:
executing program 0:
prlimit64(0x0, 0xe, &(0x7f0000000140)={0x8, 0x87}, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000040)=0x7)
timer_create(0x0, &(0x7f00000000c0)={0x0, 0x21}, &(0x7f0000000040))
timer_settime(0x0, 0x0, 0x0, 0x0)
program did not crash
extracting C reproducer
testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_create-timer_settime
program crashed: INFO: rcu detected stall in syscall_exit_to_user_mode
a never seen crash title: INFO: rcu detected stall in syscall_exit_to_user_mode, ignore
simplifying guilty program options
testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_create-timer_settime
detailed listing:
executing program 0:
prlimit64(0x0, 0xe, &(0x7f0000000140)={0x8, 0x87}, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000040)=0x7)
timer_create(0x0, &(0x7f00000000c0)={0x0, 0x21}, &(0x7f0000000040))
timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
program crashed: INFO: rcu detected stall in syscall_exit_to_user_mode
a never seen crash title: INFO: rcu detected stall in syscall_exit_to_user_mode, ignore
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_create-timer_settime
detailed listing:
executing program 0:
prlimit64(0x0, 0xe, &(0x7f0000000140)={0x8, 0x87}, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000040)=0x7)
timer_create(0x0, &(0x7f00000000c0)={0x0, 0x21}, &(0x7f0000000040))
timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
program did not crash
reproducing took 1h21m30.654158275s
repro crashed as (corrupted=true):
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
(detected by 0, t=10502 jiffies, g=7329, q=92)
rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294955361-4294944858), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10504 jiffies! g7329 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27064 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
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
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4366 Comm: syz.2.36 Not tainted 5.15.173-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:memset_erms+0xb/0x10 arch/x86/lib/memset_64.S:65
Code: 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 f3 aa <4c> 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01 01 01
RSP: 0018:ffffc900033cf8e8 EFLAGS: 00000002
RAX: dffffc0000000000 RBX: ffff8880774610d8 RCX: 0000000000000000
RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffff8880774610f0
RBP: ffff8880b8f2abc8 R08: dffffc0000000000 R09: ffff8880774610e0
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000001
R13: 1ffff110171e557b R14: 0000000000000010 R15: ffff8880b8f2abd8
FS: 00007fef729fc6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002006b000 CR3: 000000005a88c000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
rb_link_node include/linux/rbtree.h:63 [inline]
rb_add_cached include/linux/rbtree.h:182 [inline]
timerqueue_add+0x1b1/0x280 lib/timerqueue.c:40
enqueue_hrtimer+0x1a0/0x390 kernel/time/hrtimer.c:1092
__hrtimer_start_range_ns kernel/time/hrtimer.c:1259 [inline]
hrtimer_start_range_ns+0xabe/0xc80 kernel/time/hrtimer.c:1301
posixtimer_rearm+0x1ad/0x3f0 kernel/time/posix-timers.c:328
dequeue_signal+0x1ed/0x520 kernel/signal.c:696
get_signal+0x52e/0x14e0 kernel/signal.c:2781
arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307
do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fef7377e847
Code: ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 <0f> 05 48 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89
RSP: 002b:00007fef729fc0e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007fef73943fa8 RCX: 00007fef7377e849
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fef73943fa8
RBP: 00007fef73943fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fef73943fac
R13: 0000000000000000 R14: 00007fffa92d2480 R15: 00007fffa92d2568
sched: RT throttling activated
report is corrupted, running repro again
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): prlimit64-sched_setscheduler-timer_create-timer_settime
detailed listing:
executing program 0:
prlimit64(0x0, 0xe, &(0x7f0000000140)={0x8, 0x87}, 0x0)
sched_setscheduler(0x0, 0x1, &(0x7f0000000040)=0x7)
timer_create(0x0, &(0x7f00000000c0)={0x0, 0x21}, &(0x7f0000000040))
timer_settime(0x0, 0x0, &(0x7f000006b000)={{0x0, 0x8}, {0x0, 0x9}}, 0x0)
program crashed: INFO: rcu detected stall in rt_sigreturn
final repro crashed as (corrupted=false):
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
(detected by 0, t=10502 jiffies, g=7237, q=132)
rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294965324-4294954821), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10504 jiffies! g7237 f0x2 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:26816 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
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
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 4348 Comm: syz.3.26 Not tainted 5.15.173-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
rcu_check_gp_kthread_starvation+0x1d2/0x240 kernel/rcu/tree_stall.h:487
print_other_cpu_stall+0x137a/0x14d0 kernel/rcu/tree_stall.h:592
check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
rcu_pending kernel/rcu/tree.c:3932 [inline]
rcu_sched_clock_irq+0xa38/0x1150 kernel/rcu/tree.c:2619
update_process_times+0x196/0x200 kernel/time/timer.c:1818
tick_sched_handle kernel/time/tick-sched.c:254 [inline]
tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473
__run_hrtimer kernel/time/hrtimer.c:1688 [inline]
__hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1752
hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x13b/0x4b0 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:lock_acquire+0x252/0x4f0 kernel/locking/lockdep.c:5627
Code: 2b 00 74 08 4c 89 f7 e8 fc 8c 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:ffffc900032efaa0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff9200065df60 RCX: ffffffff81637932
RDX: dffffc0000000000 RSI: ffffffff8aab3d20 RDI: ffffffff8af9ed00
RBP: ffffc900032efbe8 R08: dffffc0000000000 R09: fffffbfff2131027
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200065df5c
R13: dffffc0000000000 R14: ffffc900032efb00 R15: 0000000000000246
__might_fault+0xb4/0x110 mm/memory.c:5355
_copy_from_user+0x28/0x170 lib/usercopy.c:14
copy_from_user include/linux/uaccess.h:192 [inline]
restore_sigcontext+0xce/0x710 arch/x86/kernel/signal.c:91
__do_sys_rt_sigreturn+0x190/0x250 arch/x86/kernel/signal.c:674
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: 0033:0x7fc69d935189
Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25
RSP: 002b:00007fc69cc16b40 EFLAGS: 00000206 ORIG_RAX: 000000000000000f
RAX: ffffffffffffffda RBX: 00007fc69db5efa8 RCX: 00007fc69d935189
RDX: 00007fc69cc16b40 RSI: 00007fc69cc16c70 RDI: 0000000000000021
RBP: 00007fc69db5efa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 00007fc69db5efac
R13: 0000000000000000 R14: 00007ffd05bff0b0 R15: 00007ffd05bff198