rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7671/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=16145, q=932291 ncpus=2)
task:syz.3.476 state:R running task stack:27096 pid:7671 tgid:7670 ppid:5826 task_flags:0x400140 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x116a/0x5de0 kernel/sched/core.c:6785
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7108
irqentry_exit+0x36/0x90 kernel/entry/common.c:307
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_is_held_type+0x107/0x150 kernel/locking/lockdep.c:5948
Code: 00 00 b8 ff ff ff ff 65 0f c1 05 6c 50 4d 08 83 f8 01 75 2d 9c 58 f6 c4 02 75 43 48 f7 04 24 00 02 00 00 74 01 fb 48 83 c4 08 <44> 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f e9 57 f1 02 00 45 31 ed eb
RSP: 0018:ffffc9000c3473a0 EFLAGS: 00000296
RAX: 0000000000000046 RBX: ffff88802d530b18 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8ddf41ab RDI: ffffffff8c157020
RBP: ffffffff8e61f188 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff88802d530000
R13: 0000000000000000 R14: 00000000ffffffff R15: 0000000000000002
lock_is_held include/linux/lockdep.h:249 [inline]
task_css include/linux/cgroup.h:453 [inline]
blkcg_css.part.0+0xb0/0x1d0 block/blk-cgroup.c:110
blkcg_css block/blk-cgroup.c:2259 [inline]
blk_cgroup_congested+0xf8/0x270 block/blk-cgroup.c:2256
__folio_throttle_swaprate+0xa8/0x2f0 mm/swapfile.c:3913
folio_throttle_swaprate include/linux/swap.h:636 [inline]
shmem_add_to_page_cache+0x5ab/0x9a0 mm/shmem.c:898
shmem_alloc_and_add_folio+0x668/0xc20 mm/shmem.c:1916
shmem_get_folio_gfp+0x67f/0x1600 mm/shmem.c:2532
shmem_fault+0x1fe/0xa30 mm/shmem.c:2733
__do_fault+0x10d/0x490 mm/memory.c:5189
do_read_fault mm/memory.c:5610 [inline]
do_fault mm/memory.c:5744 [inline]
do_pte_missing mm/memory.c:4251 [inline]
handle_pte_fault mm/memory.c:6089 [inline]
__handle_mm_fault+0x3c2a/0x5490 mm/memory.c:6232
handle_mm_fault+0x589/0xd10 mm/memory.c:6401
faultin_page mm/gup.c:1186 [inline]
__get_user_pages+0x589/0x3b80 mm/gup.c:1488
populate_vma_page_range+0x278/0x3a0 mm/gup.c:1926
__mm_populate+0x1d8/0x380 mm/gup.c:2029
mm_populate include/linux/mm.h:3348 [inline]
vm_mmap_pgoff+0x362/0x450 mm/util.c:584
ksys_mmap_pgoff+0x7d/0x5c0 mm/mmap.c:607
__do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
__se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
__x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcee258e929
RSP: 002b:00007fcee3489038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fcee27b5fa0 RCX: 00007fcee258e929
RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007fcee2610b39 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fcee27b5fa0 R15: 00007ffd0cb2d7a8
rcu: rcu_preempt kthread starved for 631 jiffies! g16145 f0x2 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:27784 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x116a/0x5de0 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6878
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2054
rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2256
kthread+0x3c5/0x780 kernel/kthread.c:464
ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5821 Comm: kworker/u9:2 Not tainted 6.15.0-syzkaller-13743-g8630c59e9936 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: krxrpcd rxrpc_peer_keepalive_worker
RIP: 0010:in_softirq_really kernel/kcov.c:171 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x1e/0x70 kernel/kcov.c:217
Code: 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 34 24 65 48 8b 15 58 a3 10 12 65 8b 05 69 a3 10 12 a9 00 01 ff 00 74 1d c4 01 74 43 a9 00 00 0f 00 75 3c a9 00 00 f0 00 75 35 8b 82 3c
RSP: 0018:ffffc90000a08210 EFLAGS: 00000206
RAX: 0000000080000101 RBX: 0000000000000000 RCX: ffffffff848ebef1
RDX: ffff888025844880 RSI: ffffffff848ebea6 RDI: 0000000000000005
RBP: ffff88814d4cedc0 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffffc90000a083b4
R13: 0000000000000001 R14: ffff888023fb0000 R15: 1ffff92000141049
FS: 0000000000000000(0000) GS:ffff888124854000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fab23a00000 CR3: 0000000033fcd000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
arch_static_branch arch/x86/include/asm/jump_label.h:36 [inline]
security_xfrm_decode_session+0x56/0x240 security/security.c:5453
__xfrm_decode_session+0x5c9/0xde0 net/xfrm/xfrm_policy.c:3536
xfrm_decode_session include/net/xfrm.h:1343 [inline]
ip_route_me_harder+0x89d/0x12f0 net/ipv4/netfilter.c:66
synproxy_send_tcp.isra.0+0x2fa/0x630 net/netfilter/nf_synproxy_core.c:431
synproxy_send_client_synack+0x6f6/0x8f0 net/netfilter/nf_synproxy_core.c:484
nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:59 [inline]
nft_synproxy_do_eval+0xa63/0xd80 net/netfilter/nft_synproxy.c:141
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x2e9/0x1920 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x18a/0x340 net/netfilter/nft_chain_filter.c:161
nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline]
nf_hook_slow+0xbe/0x200 net/netfilter/core.c:623
nf_hook.constprop.0+0x422/0x750 include/linux/netfilter.h:272
NF_HOOK include/linux/netfilter.h:315 [inline]
ip_local_deliver+0x169/0x1f0 net/ipv4/ip_input.c:254
dst_input include/net/dst.h:469 [inline]
ip_rcv_finish net/ipv4/ip_input.c:447 [inline]
NF_HOOK include/linux/netfilter.h:317 [inline]
NF_HOOK include/linux/netfilter.h:311 [inline]
ip_rcv+0x2c3/0x5d0 net/ipv4/ip_input.c:567
__netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:5977
__netif_receive_skb+0x1d/0x160 net/core/dev.c:6090
process_backlog+0x442/0x15e0 net/core/dev.c:6442
__napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7414
napi_poll net/core/dev.c:7478 [inline]
net_rx_action+0xa9f/0xfe0 net/core/dev.c:7605
handle_softirqs+0x219/0x8e0 kernel/softirq.c:579
do_softirq kernel/softirq.c:480 [inline]
do_softirq+0xb2/0xf0 kernel/softirq.c:467
__local_bh_enable_ip+0x100/0x120 kernel/softirq.c:407
spin_unlock_bh include/linux/spinlock.h:396 [inline]
rxrpc_peer_keepalive_dispatch net/rxrpc/peer_event.c:295 [inline]
rxrpc_peer_keepalive_worker+0xa54/0xef0 net/rxrpc/peer_event.c:341
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3321 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
kthread+0x3c5/0x780 kernel/kthread.c:464
ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245