rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5873/1:b..l P5783/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=11021, q=775 ncpus=2)
task:udevd state:R running task stack:24968 pid:5783 ppid:5140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x14e2/0x4580 kernel/sched/core.c:6700
preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6867
preempt_schedule+0xab/0xc0 kernel/sched/core.c:6891
preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
_raw_spin_unlock_irq+0x40/0x50 kernel/locking/spinlock.c:202
spin_unlock_irq include/linux/spinlock.h:401 [inline]
loop_queue_work drivers/block/loop.c:894 [inline]
loop_queue_rq+0x9dd/0xac0 drivers/block/loop.c:1878
__blk_mq_issue_directly block/blk-mq.c:2650 [inline]
blk_mq_request_issue_directly+0x48b/0x7e0 block/blk-mq.c:2737
blk_mq_plug_issue_direct+0x233/0x590 block/blk-mq.c:2758
blk_mq_flush_plug_list+0x8a8/0x1730 block/blk-mq.c:2872
__blk_flush_plug+0x3ca/0x440 block/blk-core.c:1163
blk_finish_plug+0x5d/0x80 block/blk-core.c:1187
read_pages+0x644/0x840 mm/readahead.c:183
page_cache_ra_unbounded+0x692/0x770 mm/readahead.c:269
do_page_cache_ra mm/readahead.c:299 [inline]
force_page_cache_ra mm/readahead.c:330 [inline]
page_cache_sync_ra+0x3db/0x490 mm/readahead.c:694
page_cache_sync_readahead include/linux/pagemap.h:1325 [inline]
filemap_get_pages+0x3ac/0x1e10 mm/filemap.c:2594
filemap_read+0x3d0/0xec0 mm/filemap.c:2690
blkdev_read_iter+0x2e1/0x400 block/fops.c:731
call_read_iter include/linux/fs.h:2012 [inline]
new_sync_read fs/read_write.c:389 [inline]
vfs_read+0x431/0x920 fs/read_write.c:470
ksys_read+0x147/0x250 fs/read_write.c:613
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f3f830a7407
RSP: 002b:00007ffee5d418f0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f3f837bc880 RCX: 00007f3f830a7407
RDX: 0000000000000200 RSI: 00007f3f837af000 RDI: 0000000000000009
RBP: 00005625532c4000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000001f6
R13: 000000000000fe00 R14: 00005625532d8bd8 R15: 00007f3f838e339c
task:syz.0.6 state:R running task stack:25384 pid:5873 ppid:5771 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x14e2/0x4580 kernel/sched/core.c:6700
preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7010
irqentry_exit+0x67/0x70 kernel/entry/common.c:438
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:get_current arch/x86/include/asm/current.h:41 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:244 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x8/0x90 kernel/kcov.c:313
Code: 08 03 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 15 70 20 7e 7e 65 8b 0d 71 20 7e 7e 81 e1 00 01 ff 00 74
RSP: 0018:ffffc90004b67488 EFLAGS: 00000246
RAX: ffffffff840ba4a0 RBX: ffffffff840ba32f RCX: ffff88802afbda00
RDX: ffffc9000c65b000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff8880252449eb R09: 1ffff11004a4893d
R10: dffffc0000000000 R11: ffffed1004a4893e R12: dffffc0000000000
R13: 00000000000009b8 R14: 0000000000000001 R15: ffff8880252449e8
rcu_read_unlock include/linux/rcupdate.h:815 [inline]
blk_cgroup_congested+0x190/0x220 block/blk-cgroup.c:2204
__folio_throttle_swaprate+0x71/0x1a0 mm/swapfile.c:3649
folio_throttle_swaprate include/linux/swap.h:638 [inline]
shmem_add_to_page_cache+0x9c0/0x1b40 mm/shmem.c:794
shmem_get_folio_gfp+0xf05/0x2ac0 mm/shmem.c:2072
shmem_fault+0x1b6/0x7f0 mm/shmem.c:2249
__do_fault+0x13b/0x4e0 mm/memory.c:4243
do_read_fault mm/memory.c:4616 [inline]
do_fault mm/memory.c:4753 [inline]
do_pte_missing mm/memory.c:3688 [inline]
handle_pte_fault mm/memory.c:5025 [inline]
__handle_mm_fault mm/memory.c:5166 [inline]
handle_mm_fault+0x3886/0x4920 mm/memory.c:5331
faultin_page mm/gup.c:868 [inline]
__get_user_pages+0x5ea/0x1470 mm/gup.c:1167
populate_vma_page_range+0x2b6/0x370 mm/gup.c:1593
__mm_populate+0x24c/0x380 mm/gup.c:1696
mm_populate include/linux/mm.h:3312 [inline]
vm_mmap_pgoff+0x2e7/0x400 mm/util.c:561
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa0ad58e929
RSP: 002b:00007fa0ae353038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fa0ad7b5fa0 RCX: 00007fa0ad58e929
RDX: b635773f06ebbeef RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007fa0ad610b39 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fa0ad7b5fa0 R15: 00007ffdfa88a378
rcu: rcu_preempt kthread starved for 10561 jiffies! g11021 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:27496 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x14e2/0x4580 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_timeout+0x160/0x280 kernel/time/timer.c:2167
rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x99/0x380 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
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: 0 Comm: swapper/0 Not tainted 6.6.94-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:148
Code: 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 63 f0 41 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 66 0f 1f 00 55 41 57 41 56
RSP: 0018:ffffffff8ca07d80 EFLAGS: 000002c2
RAX: 8af0180fb4c21700 RBX: ffffffff81618a7b RCX: 8af0180fb4c21700
RDX: 0000000000000001 RSI: ffffffff8aaab2c0 RDI: ffffffff8afc6900
RBP: ffffffff8ca07eb8 R08: ffff8880b8e36d4b R09: 1ffff110171c6da9
R10: dffffc0000000000 R11: ffffed10171c6daa R12: ffffffff8e49ab28
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1952670
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3f837b0000 CR3: 00000000769c5000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
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:170 [inline]
do_idle+0x1eb/0x510 kernel/sched/idle.c:282
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:380
rest_init+0x2e2/0x300 init/main.c:732
arch_call_rest_init+0xe/0x10 init/main.c:829
start_kernel+0x459/0x4e0 init/main.c:1074
x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
x86_64_start_kernel+0x60/0x60 arch/x86/kernel/head64.c:536
secondary_startup_64_no_verify+0x179/0x17b
sched: RT throttling activated