rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8057/1:b..l
(detected by 0, t=10508 jiffies, g=28285, q=24 ncpus=2)
task:syz.0.1319 state:R running task stack:23744 pid:8057 ppid:8056 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
preempt_schedule_notrace+0xca/0x110 kernel/sched/core.c:6823
preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35
rcu_is_watching+0x76/0xa0 kernel/rcu/tree.c:722
rcu_read_lock include/linux/rcupdate.h:792 [inline]
mtree_load+0x129/0xa40 lib/maple_tree.c:6253
vma_lookup include/linux/mm.h:2905 [inline]
__get_user_pages+0x25a/0xeb0 mm/gup.c:1202
__get_user_pages_locked mm/gup.c:1454 [inline]
get_dump_page+0x188/0x670 mm/gup.c:1952
dump_user_range+0x128/0x7f0 fs/coredump.c:975
elf_core_dump+0x2f77/0x3490 fs/binfmt_elf.c:2354
do_coredump+0x15ff/0x22b0 fs/coredump.c:824
get_signal+0x10aa/0x1350 kernel/signal.c:2857
arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:316
exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1490
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7f9fa238ebf1
RSP: 002b:0000000000000030 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f9fa25c5fa0 RCX: 00007f9fa238ebe9
RDX: 0000000000000000 RSI: 0000000000000030 RDI: 0000000000000000
RBP: 00007f9fa2411e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9fa25c6038 R14: 00007f9fa25c5fa0 R15: 00007fff8c0cf738
rcu: rcu_preempt kthread starved for 10543 jiffies! g28285 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:28192 pid:16 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965
rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
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: 8063 Comm: syz.3.1321 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:orc_ip arch/x86/kernel/unwind_orc.c:30 [inline]
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:52 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:178 [inline]
RIP: 0010:unwind_next_frame+0x1361/0x20b0 arch/x86/kernel/unwind_orc.c:448
Code: e8 3f 48 01 c8 48 83 e0 fe 4d 8d 74 45 00 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 27 49 63 06 <4c> 01 f0 49 8d 4e 04 48 39 e8 4c 0f 46 e9 49 8d 46 fc 4c 0f 47 e0
RSP: 0018:ffffc9000e61f5f0 EFLAGS: 00000046
RAX: fffffffffb824901 RBX: ffffc9000e61f6c8 RCX: dffffc0000000000
RDX: ffffffff8f3746ca RSI: ffffffff8e94b964 RDI: 0000000000000001
RBP: ffffffff8a170237 R08: 0000000000000007 R09: 000000000000000c
R10: fffff52001cc3ee5 R11: 1ffff92001cc3ee3 R12: ffffffff8e94b97c
R13: ffffffff8e94b964 R14: ffffffff8e94b970 R15: ffffffff8e94b964
FS: 00007fbde666c6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c244a46 CR3: 000000007e217000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
kasan_save_free_info+0x2d/0x50 mm/kasan/generic.c:516
____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236
kasan_slab_free include/linux/kasan.h:177 [inline]
slab_free_hook mm/slub.c:1724 [inline]
slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1750
slab_free mm/slub.c:3661 [inline]
kmem_cache_free+0xf7/0x290 mm/slub.c:3683
__sigqueue_free kernel/signal.c:459 [inline]
collect_signal kernel/signal.c:602 [inline]
__dequeue_signal+0x4e9/0x610 kernel/signal.c:624
dequeue_signal+0xe5/0x4b0 kernel/signal.c:647
get_signal+0x547/0x1350 kernel/signal.c:2751
arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fbde578ebe9
Code: 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 01 48
RSP: 002b:00007fbde666c0e8 EFLAGS: 00000246
RAX: fffffffffffffffc RBX: 00007fbde59c6098 RCX: 00007fbde578ebe9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fbde59c6098
RBP: 00007fbde59c6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbde59c6128 R14: 00007ffde0fd4db0 R15: 00007ffde0fd4e98