rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6943/3:b..l P6933/3:b..l P6939/1:b.el
rcu: (detected by 0, t=10506 jiffies, g=15373, q=1767 ncpus=2)
task:modprobe state:R running task stack:24584 pid:6939 tgid:6939 ppid:80 task_flags:0x400000 flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256
irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 fb 1c f4 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc9000bd6f258 EFLAGS: 00000206
RAX: 69cf8838c8fc0500 RBX: 0000000000000000 RCX: 69cf8838c8fc0500
RDX: 0000000000000000 RSI: ffffffff8d9d4aee RDI: ffffffff8bc07760
RBP: ffffffff8173cd25 R08: 0000000000000000 R09: ffffffff8173cd25
R10: ffffc9000bd6f418 R11: ffffffff81ac6cd0 R12: 0000000000000002
R13: ffffffff8e13d2e0 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
unpoison_slab_object mm/kasan/common.c:342 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4955 [inline]
slab_alloc_node mm/slub.c:5265 [inline]
kmem_cache_alloc_noprof+0x367/0x6e0 mm/slub.c:5272
vm_area_dup+0x2b/0x680 mm/vma_init.c:123
__split_vma+0x1a9/0xa00 mm/vma.c:515
split_vma mm/vma.c:598 [inline]
vma_modify+0x13b3/0x1970 mm/vma.c:1631
vma_modify_flags+0x1e8/0x230 mm/vma.c:1649
mprotect_fixup+0x407/0x9c0 mm/mprotect.c:816
do_mprotect_pkey+0x8c5/0xcd0 mm/mprotect.c:990
__do_sys_mprotect mm/mprotect.c:1011 [inline]
__se_sys_mprotect mm/mprotect.c:1008 [inline]
__x64_sys_mprotect+0x80/0x90 mm/mprotect.c:1008
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8f7947c2c7
RSP: 002b:00007ffc24a22cf8 EFLAGS: 00000206 ORIG_RAX: 000000000000000a
RAX: ffffffffffffffda RBX: 00007f8f79451ab0 RCX: 00007f8f7947c2c7
RDX: 0000000000000001 RSI: 0000000000001000 RDI: 00007f8f79181000
RBP: 00007ffc24a22fc0 R08: 0000000000000000 R09: 00007f8f792b0700
R10: 00007f8f79451ab0 R11: 0000000000000206 R12: 0000000000000028
R13: 0000003f2dca6d95 R14: 0000000000000000 R15: 00007f8f79490310
task:modprobe state:R running task stack:24584 pid:6933 tgid:6933 ppid:60 task_flags:0x400000 flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7113
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7137
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
filemap_map_pages+0x1621/0x1c60 mm/filemap.c:3858
do_fault_around mm/memory.c:5656 [inline]
do_read_fault mm/memory.c:5689 [inline]
do_fault mm/memory.c:5832 [inline]
do_pte_missing mm/memory.c:4361 [inline]
handle_pte_fault mm/memory.c:6177 [inline]
__handle_mm_fault+0x347e/0x5400 mm/memory.c:6318
handle_mm_fault+0x40a/0x8e0 mm/memory.c:6487
do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f14b324ec50
RSP: 002b:00007ffefa9df5b8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00005609f5a47910 RCX: 0000000000000000
RDX: 00007f14b327dc40 RSI: 00007f14b327dc14 RDI: 00007ffefa9df838
RBP: 00007ffefa9df838 R08: 00007f14b31b5ac0 R09: 0000000000000000
R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffefa9df860 R14: 00007f14b32c5000 R15: 00005609b5e45d98
task:modprobe state:R running task stack:24584 pid:6943 tgid:6943 ppid:1150 task_flags:0x400000 flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7113
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7137
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
filemap_map_pages+0x1621/0x1c60 mm/filemap.c:3858
do_fault_around mm/memory.c:5656 [inline]
do_read_fault mm/memory.c:5689 [inline]
do_fault mm/memory.c:5832 [inline]
do_pte_missing mm/memory.c:4361 [inline]
handle_pte_fault mm/memory.c:6177 [inline]
__handle_mm_fault+0x347e/0x5400 mm/memory.c:6318
handle_mm_fault+0x40a/0x8e0 mm/memory.c:6487
do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f02550c2230
RSP: 002b:00007fffca495f18 EFLAGS: 00010202
RAX: 00007f02551a5120 RBX: 0000000000000001 RCX: ffffffffffffff98
RDX: ffffffffffffff90 RSI: 00007fffca495f20 RDI: 0000000000000003
RBP: 00007fffca4961f0 R08: 0000000000000000 R09: 000000000000000e
R10: fffffffffffff68e R11: 0000000000000206 R12: fffffffffffffff8
R13: 0000003f2ad427c9 R14: 0000000000000000 R15: 00007f02552ae310
rcu: rcu_preempt kthread starved for 10504 jiffies! g15373 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:27224 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 1112 Comm: kworker/u8:6 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: writeback wb_workfn (flush-8:0)
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xd38/0x12d0 kernel/smp.c:877
Code: 89 ee 83 e6 01 31 ff e8 96 73 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 41 6f 0b 00 eb 38 f3 90 42 0f b6 04 2b <84> c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 25 6f 0b 00 eb e4 44
RSP: 0018:ffffc90004106040 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 1ffff110170e7ffd RCX: ffff8880268a8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900041061c0 R08: ffff88807d0d2a47 R09: 1ffff1100fa1a548
R10: dffffc0000000000 R11: ffffffff8175c760 R12: ffff8880b873ffe8
R13: dffffc0000000000 R14: ffff8880b863b240 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125d05000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056103bf7f950 CR3: 00000000781f8000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
flush_tlb_mm_range+0x6b1/0x12d0 arch/x86/mm/tlb.c:1451
flush_tlb_page arch/x86/include/asm/tlbflush.h:324 [inline]
ptep_clear_flush+0x120/0x170 mm/pgtable-generic.c:101
page_vma_mkclean_one+0x406/0x740 mm/rmap.c:1041
page_mkclean_one+0x1c0/0x280 mm/rmap.c:1082
__rmap_walk_file+0x467/0x620 mm/rmap.c:2918
rmap_walk mm/rmap.c:2962 [inline]
folio_mkclean+0x297/0x390 mm/rmap.c:1114
folio_clear_dirty_for_io+0x1f5/0x880 mm/page-writeback.c:2938
mpage_submit_folio+0x86/0x2b0 fs/ext4/inode.c:2061
mpage_process_page_bufs+0x6d5/0x8e0 fs/ext4/inode.c:2191
mpage_prepare_extent_to_map+0xe6c/0x16e0 fs/ext4/inode.c:2736
ext4_do_writepages+0xba0/0x4610 fs/ext4/inode.c:2877
ext4_writepages+0x205/0x350 fs/ext4/inode.c:3025
do_writepages+0x32e/0x550 mm/page-writeback.c:2604
__writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1719
writeback_sb_inodes+0x6c7/0x1010 fs/fs-writeback.c:2015
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2086
wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2197
wb_check_old_data_flush fs/fs-writeback.c:2301 [inline]
wb_do_writeback fs/fs-writeback.c:2354 [inline]
wb_workfn+0xaef/0xef0 fs/fs-writeback.c:2382
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245