rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12804/1:b..l P12809/1:b..l
(detected by 0, t=10502 jiffies, g=79941, q=124 ncpus=2)
task:udevd state:R running task stack:24032 pid:12809 ppid:3637 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
irqentry_exit+0x63/0x70 kernel/entry/common.c:439
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:ma_is_root lib/maple_tree.c:337 [inline]
RIP: 0010:mte_is_root lib/maple_tree.c:342 [inline]
RIP: 0010:mas_validate_limits lib/maple_tree.c:7112 [inline]
RIP: 0010:mt_validate+0x1902/0x4c90 lib/maple_tree.c:7242
Code: 00 00 00 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 5f 84 cb f7 48 8b 1b 48 89 de 48 83 e6 01 31 ff e8 2e 59 7b f7 <48> 83 e3 01 0f 85 ea 07 00 00 48 8b 5c 24 50 4c 8d bb 80 5e b1 8b
RSP: 0018:ffffc900036778e0 EFLAGS: 00000293
RAX: ffffffff8a058112 RBX: ffff88802e2b602e RCX: ffff88807c950000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003677ab0 R08: ffff88807c950000 R09: 0000000000000003
R10: 0000000000000003 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff888027dd4280 R14: 0000000000000001 R15: 0000000000000001
validate_mm_mt+0xcd/0x420 mm/mmap.c:295
validate_mm+0xcc/0x2b0 mm/mmap.c:332
do_mmap+0xc7/0xfd0 mm/mmap.c:1270
vm_mmap_pgoff+0x1b2/0x2b0 mm/util.c:520
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f0eb3d1d822
RSP: 002b:00007ffd7ba56008 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0eb3d1d822
RDX: 0000000000000003 RSI: 0000000000000400 RDI: 0000000000000000
RBP: 0000000000000022 R08: 00000000ffffffff R09: 0000000000000000
R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000400 R14: 000055ffcaec90b0 R15: 0000000000000400
task:udevd state:R running task stack:23936 pid:12804 ppid:3637 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6730
preempt_schedule+0xa7/0xb0 kernel/sched/core.c:6754
preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
vprintk_emit+0x5c9/0x680 kernel/printk/printk.c:2304
_printk+0xcc/0x110 kernel/printk/printk.c:2328
blk_print_req_error+0x175/0x210 block/blk-mq.c:796
blk_update_request+0xbab/0xe30 block/blk-mq.c:909
blk_mq_end_request block/blk-mq.c:1050 [inline]
blk_mq_plug_issue_direct+0x286/0x620 block/blk-mq.c:2749
blk_mq_flush_plug_list+0x7e7/0xd40 block/blk-mq.c:2838
__blk_flush_plug+0x3c6/0x440 block/blk-core.c:1179
blk_finish_plug+0x59/0x80 block/blk-core.c:1203
read_pages+0x646/0x840 mm/readahead.c:184
page_cache_ra_unbounded+0x690/0x770 mm/readahead.c:270
do_page_cache_ra mm/readahead.c:300 [inline]
force_page_cache_ra mm/readahead.c:331 [inline]
page_cache_sync_ra+0x3d7/0x490 mm/readahead.c:713
page_cache_sync_readahead include/linux/pagemap.h:1248 [inline]
filemap_get_pages mm/filemap.c:2665 [inline]
filemap_read+0x5ff/0x2f80 mm/filemap.c:2759
blkdev_read_iter+0x3d5/0x500 block/fops.c:614
call_read_iter include/linux/fs.h:2259 [inline]
new_sync_read fs/read_write.c:389 [inline]
vfs_read+0x434/0x920 fs/read_write.c:470
ksys_read+0x143/0x240 fs/read_write.c:613
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f0eb3ca7407
RSP: 002b:00007ffd7ba55fc0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f0eb43c5880 RCX: 00007f0eb3ca7407
RDX: 0000000000000200 RSI: 00007f0eb43c4000 RDI: 0000000000000009
RBP: 000055ffcaec9050 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000000 R14: 000055ffcaed01c8 R15: 00007f0eb44ec39c
rcu: rcu_preempt kthread starved for 10559 jiffies! g79941 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:27424 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:2167
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: 14154 Comm: syz.2.2852 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:__lock_acquire+0xfea/0x7c50 kernel/locking/lockdep.c:-1
Code: 8b 7c 24 40 e8 17 f8 6d 00 eb bb 44 89 e0 25 ff 1f 00 00 41 c1 ec 03 41 81 e4 00 60 00 00 41 09 c4 4c 89 ee 48 c1 ee 20 89 f0 c0 04 41 29 f4 44 31 e0 44 01 ee 41 29 c5 89 c1 c1 c1 06 44 31
RSP: 0018:ffffc900050e7760 EFLAGS: 00000807
RAX: 00000000ffffffff RBX: 0000000000000000 RCX: ffffffff96be9101
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff90ae2270
RBP: ffffc900050e79b0 R08: dffffc0000000000 R09: fffffbfff215c44f
R10: fffffbfff215c44f R11: 1ffffffff215c44e R12: 000000000000219c
R13: ffffffffffffffff R14: ffff88802a0c6420 R15: ffff88802a0c6440
FS: 0000555558475500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc50cfbf80 CR3: 00000000657fa000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
__might_fault+0xc2/0x120 mm/memory.c:5852
__copy_from_user include/linux/uaccess.h:75 [inline]
check_xstate_in_sigframe arch/x86/kernel/fpu/signal.c:35 [inline]
__fpu_restore_sig arch/x86/kernel/fpu/signal.c:348 [inline]
fpu__restore_sig+0x203/0x1190 arch/x86/kernel/fpu/signal.c:493
restore_sigcontext arch/x86/kernel/signal.c:140 [inline]
__ia32_sys_rt_sigreturn+0x649/0x790 arch/x86/kernel/signal.c:675
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f1ab0a4d723
Code: 00 00 00 0f 1f 40 00 41 89 fb 44 8d 56 04 4c 8d 0d f2 48 38 00 89 f0 4c 8d 05 e9 28 38 00 89 c2 81 e2 ff 1f 00 00 49 8b 0c d1 <48> 39 f1 74 28 48 85 c9 74 29 45 38 1c 10 75 23 83 c0 01 44 39 d0
RSP: 002b:00007ffc50cfc228 EFLAGS: 00000202
RAX: 0000000081714023 RBX: 00007f1ab1915720 RCX: ffffffff81be6023
RDX: 0000000000000023 RSI: ffffffff81714023 RDI: 0000000000000011
RBP: ffffffff81714023 R08: 00007f1ab0dd0000 R09: 00007f1ab0dd2000
R10: 0000000081714027 R11: 0000000000000011 R12: 0000000000000011
R13: 0000000000000000 R14: ffffffff81714670 R15: 0000000000000032