syzbot
INFO: rcu detected stall in sys_execve (2)
Status:
upstream: reported on 2026/10/03 15:57
Reported-by: syzbot+d77ed98e0b6bf046e345@syzkaller.appspotmail.com
First crash: 19d, last: 12d
Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9058/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=46213, q=194 ncpus=2)
task:sed state:R running task stack:25544 pid:9058 ppid:9057 flags:0x00004002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7011
irqentry_exit+0x67/0x70 kernel/entry/common.c:441
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:208
Code: 00 0f 0b 0f 1f 80 00 00 00 00 f3 0f 1e fa 53 48 89 fb e8 13 00 00 00 48 8b 3d 7c cc e4 0d 48 89 de 5b e9 73 10 58 00 cc cc cc <f3> 0f 1e fa 48 8b 04 24 65 48 8b 0d 40 27 7c 7e 65 8b 15 41 27 7c
RSP: 0018:ffffc9000515f598 EFLAGS: 00000246
RAX: 0000000000000003 RBX: ffff88805ccf3240 RCX: 0000000000000005
RDX: ffffffff8a8089f8 RSI: ffffffff8f541750 RDI: 0000000000000001
RBP: ffffc9000515f750 R08: ffff8880317e8000 R09: 0000000000000003
R10: 0000000000000002 R11: 0000000000000000 R12: ffff88805ccf3200
R13: 00007f7cee1aefff R14: 0000000000000001 R15: 0000556698094000
ma_slots lib/maple_tree.c:787 [inline]
mas_get_slot lib/maple_tree.c:6690 [inline]
mas_validate_gaps lib/maple_tree.c:6959 [inline]
mt_validate+0x248a/0x4410 lib/maple_tree.c:7234
validate_mm+0xc6/0x450 mm/mmap.c:288
vma_link+0x41a/0x530 mm/mmap.c:416
insert_vm_struct+0x2f1/0x400 mm/mmap.c:3372
__install_special_mapping+0x194/0x320 mm/mmap.c:3616
map_vdso+0x153/0x390 arch/x86/entry/vdso/vma.c:245
load_elf_binary+0x1cd9/0x2850 fs/binfmt_elf.c:1308
search_binary_handler fs/exec.c:1794 [inline]
exec_binprm fs/exec.c:1836 [inline]
bprm_execve+0xb0b/0x1730 fs/exec.c:1911
do_execveat_common+0x501/0x6b0 fs/exec.c:2017
do_execve fs/exec.c:2091 [inline]
__do_sys_execve fs/exec.c:2167 [inline]
__se_sys_execve fs/exec.c:2162 [inline]
__x64_sys_execve+0x92/0xa0 fs/exec.c:2162
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff236cd9107
RSP: 002b:00007ffda9392948 EFLAGS: 00000246 ORIG_RAX: 000000000000003b
RAX: ffffffffffffffda RBX: 000055ff52c3e078 RCX: 00007ff236cd9107
RDX: 000055ff52c3e0a0 RSI: 000055ff52c3e078 RDI: 000055ff52c3e130
RBP: 000055ff52c3e130 R08: 00007ffda9396eab R09: 0000000000000000
R10: 0000000000000008 R11: 0000000000000246 R12: 000055ff52c3e0a0
R13: 00007ff236e9ee8b R14: 000055ff52c3e0a0 R15: 0000000000000000
</TASK>
rcu: rcu_preempt kthread starved for 631 jiffies! g46213 f0x0 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:27592 pid:17 ppid:2 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x30d/0x1590 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:148
Code: 99 17 02 c3 cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d 13 39 35 00 fb f4 <c3> 66 0f 1f 00 55 41 57 41 56 41 54 53 50 8b 2f eb 2c 89 cb 80 f9
RSP: 0018:ffffc90000187de0 EFLAGS: 000002c6
RAX: 8a122a72d3e1a600 RBX: ffffffff81631e31 RCX: 8a122a72d3e1a600
RDX: 0000000000000001 RSI: ffffffff8acacfe0 RDI: ffffffff8b1d5160
RBP: ffffc90000187f20 R08: ffff8880b8d36b6b R09: 1ffff110171a6d6d
R10: dffffc0000000000 R11: ffffed10171a6d6e R12: 1ffff92000030fc8
R13: dffffc0000000000 R14: 1ffff110039c8780 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b8d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2dd12ff8 CR3: 00000000766ba000 CR4: 00000000003506e0
Call Trace:
<TASK>
arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:753
default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97
cpuidle_idle_call kernel/sched/idle.c:178 [inline]
do_idle+0x221/0x5c0 kernel/sched/idle.c:302
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:401
start_secondary+0xee/0xf0 arch/x86/kernel/smpboot.c:323
secondary_startup_64_no_verify+0x179/0x17b
</TASK>
* Struck through repros no longer work on HEAD.