rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P155/1:b..l P4309/1:b..l
(detected by 1, t=10503 jiffies, g=7933, q=156)
task:syz.3.16 state:R running task stack:26240 pid: 4309 ppid: 4180 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6780
irqentry_exit+0x63/0x70 kernel/entry/common.c:432
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:lock_acquire+0x1f2/0x3f0 kernel/locking/lockdep.c:5627
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f6 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b
RSP: 0018:ffffc9000337ef60 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 875d4232373d3800
RDX: 0000000000000000 RSI: ffffffff8a0b2260 RDI: ffffffff8a59a2c0
RBP: ffffc9000337f080 R08: dffffc0000000000 R09: fffffbfff1ff3219
R10: fffffbfff1ff3219 R11: 1ffffffff1ff3218 R12: ffffffff8c11be60
R13: 1ffff9200066fdf8 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312
rcu_read_lock include/linux/rcupdate.h:739 [inline]
is_bpf_text_address+0x1d/0x270 kernel/bpf/core.c:725
kernel_text_address kernel/extable.c:151 [inline]
__kernel_text_address+0x9a/0x100 kernel/extable.c:105
unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323
arch_stack_walk+0xf2/0x140 arch/x86/kernel/stacktrace.c:26
stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_hook mm/slub.c:1705 [inline]
slab_free_freelist_hook+0xea/0x170 mm/slub.c:1731
slab_free mm/slub.c:3499 [inline]
kmem_cache_free+0x8f/0x210 mm/slub.c:3515
pgtable_pte_page_dtor include/linux/mm.h:2266 [inline]
___pte_free_tlb+0x88/0x2a0 arch/x86/mm/pgtable.c:55
__pte_free_tlb arch/x86/include/asm/pgalloc.h:61 [inline]
free_pte_range mm/memory.c:231 [inline]
free_pmd_range mm/memory.c:249 [inline]
free_pud_range mm/memory.c:283 [inline]
free_p4d_range mm/memory.c:317 [inline]
free_pgd_range+0x622/0xb00 mm/memory.c:397
free_pgtables+0x271/0x2a0 mm/memory.c:-1
exit_mmap+0x39e/0x5f0 mm/mmap.c:3205
__mmput+0x115/0x3b0 kernel/fork.c:1127
exit_mm+0x567/0x6c0 kernel/exit.c:550
do_exit+0x599/0x20a0 kernel/exit.c:861
do_group_exit+0x12e/0x300 kernel/exit.c:996
get_signal+0x6ca/0x12c0 kernel/signal.c:2900
arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x9e/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+0x16/0x40 kernel/entry/common.c:307
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f039d9ec969
RSP: 002b:00007f039b8330e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f039dc14088 RCX: 00007f039d9ec969
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f039dc14088
RBP: 00007f039dc14080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f039dc1408c
R13: 0000000000000000 R14: 00007ffd9c3c9310 R15: 00007ffd9c3c93f8
task:kworker/u4:3 state:D stack:21128 pid: 155 ppid: 2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
preempt_schedule_notrace+0xca/0x110 kernel/sched/core.c:6631
preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35
rcu_is_watching+0x72/0xa0 kernel/rcu/tree.c:1124
trace_lock_acquire include/trace/events/lock.h:13 [inline]
lock_acquire+0xcd/0x3f0 kernel/locking/lockdep.c:5594
rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312
rcu_read_lock include/linux/rcupdate.h:739 [inline]
percpu_ref_put_many include/linux/percpu-refcount.h:317 [inline]
percpu_ref_put include/linux/percpu-refcount.h:338 [inline]
blk_mq_sched_insert_requests+0x32e/0x5c0 block/blk-mq-sched.c:521
blk_mq_flush_plug_list+0x57f/0x660 block/blk-mq.c:1971
blk_flush_plug_list+0x3ec/0x430 block/blk-core.c:1734
blk_schedule_flush_plug include/linux/blkdev.h:1235 [inline]
sched_submit_work kernel/sched/core.c:6439 [inline]
schedule+0xf8/0x1e0 kernel/sched/core.c:6456
rwsem_down_write_slowpath+0xc46/0x11f0 kernel/locking/rwsem.c:1165
ext4_map_blocks+0x8b2/0x1b30 fs/ext4/inode.c:666
mpage_map_one_extent fs/ext4/inode.c:2408 [inline]
mpage_map_and_submit_extent fs/ext4/inode.c:2461 [inline]
ext4_writepages+0x12ca/0x2d20 fs/ext4/inode.c:2829
do_writepages+0x48d/0x6d0 mm/page-writeback.c:2386
__writeback_single_inode+0x153/0xda0 fs/fs-writeback.c:1647
writeback_sb_inodes+0x9fe/0x1610 fs/fs-writeback.c:1930
__writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:2001
wb_writeback+0x455/0xb90 fs/fs-writeback.c:2106
wb_check_old_data_flush fs/fs-writeback.c:2206 [inline]
wb_do_writeback fs/fs-writeback.c:2259 [inline]
wb_workfn+0xaaa/0xe60 fs/fs-writeback.c:2288
process_one_work+0x863/0x1000 kernel/workqueue.c:2310
worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
rcu: rcu_preempt kthread starved for 10602 jiffies! g7933 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:27808 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
schedule+0x11b/0x1e0 kernel/sched/core.c:6459
schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
kthread+0x436/0x520 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4330 Comm: syz.1.19 Not tainted 5.15.181-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
RIP: 0010:user_exit_irqoff include/linux/context_tracking.h:47 [inline]
RIP: 0010:__enter_from_user_mode kernel/entry/common.c:22 [inline]
RIP: 0010:syscall_enter_from_user_mode+0x4c/0x70 kernel/entry/common.c:110
Code: 65 48 8b 05 76 37 61 76 48 8b 70 08 40 f6 c6 3f 74 0b 4c 89 f7 5b 41 5e e9 51 db c4 f7 48 89 d8 5b 41 5e c3 eb 10 0f 0b eb c9 01 00 00 00 e8 1a 04 00 00 eb bf 65 8b 05 a1 1b 62 76 83 f8 01
RSP: 0018:ffffc9000345ff08 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 000000000000000f RCX: 81d5de03d75bb200
RDX: 0000000000000000 RSI: ffffffff8a0b0fc0 RDI: ffffffff8a59a2c0
RBP: ffffc9000345ff48 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffffc9000345ff58 R15: 0000000000000000
FS: 00007f2439f436c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 0000000058369000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
do_syscall_64+0x24/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f243c098b39
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:00007f2439f42b40 EFLAGS: 00000206 ORIG_RAX: 000000000000000f
RAX: ffffffffffffffda RBX: 00007f243c324088 RCX: 00007f243c098b39
RDX: 00007f2439f42b40 RSI: 00007f2439f42c70 RDI: 0000000000000021
RBP: 00007f243c324080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 00007f243c32408c
R13: 0000000000000000 R14: 00007fff75b31720 R15: 00007fff75b31808
sched: RT throttling activated