rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5982/2:b..l P5996/2:b..l rcu: (detected by 0, t=10502 jiffies, g=18165, q=690 ncpus=2) task:udevadm state:R running task stack:23680 pid:5996 tgid:5996 ppid:5145 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5248 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6600 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6922 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5820 Code: 2b 00 74 08 4c 89 f7 e8 aa e6 8a 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc90002e1f6a0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920005c3ee0 RCX: 6e9e6ca52bba4e00 RDX: dffffc0000000000 RSI: ffffffff8bcada80 RDI: ffffffff8c207f20 RBP: ffffc90002e1f7e8 R08: ffffffff93010787 R09: 1ffffffff26020f0 R10: dffffc0000000000 R11: fffffbfff26020f1 R12: 1ffff920005c3edc R13: dffffc0000000000 R14: ffffc90002e1f700 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:333 [inline] rcu_read_lock include/linux/rcupdate.h:845 [inline] prepend_path+0x1f0/0xbe0 fs/d_path.c:168 d_absolute_path+0x179/0x310 fs/d_path.c:234 tomoyo_get_absolute_path security/tomoyo/realpath.c:101 [inline] tomoyo_realpath_from_path+0x2b4/0x5e0 security/tomoyo/realpath.c:271 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x2b7/0x740 security/tomoyo/file.c:822 security_inode_getattr+0xd8/0x130 security/security.c:2272 vfs_getattr+0x45/0x430 fs/stat.c:204 vfs_fstat fs/stat.c:229 [inline] vfs_fstatat+0xe4/0x190 fs/stat.c:340 __do_sys_newfstatat fs/stat.c:507 [inline] __se_sys_newfstatat fs/stat.c:501 [inline] __x64_sys_newfstatat+0x11d/0x1a0 fs/stat.c:501 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f78c37165f4 RSP: 002b:00007ffd60bccc48 EFLAGS: 00000206 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 00007f78c37ee460 RCX: 00007f78c37165f4 RDX: 00007ffd60bccc50 RSI: 00007f78c37b3130 RDI: 0000000000000005 RBP: 0000560deccc62a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000001000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000003fff R14: 00007ffd60bcd1e8 R15: 000000000000000a task:syz.4.150 state:R running task stack:21040 pid:5982 tgid:5980 ppid:5561 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5248 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6600 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6779 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6803 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __local_bh_enable_ip+0x179/0x200 kernel/softirq.c:389 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:915 [inline] __dev_queue_xmit+0x1763/0x3e90 net/core/dev.c:4450 dev_queue_xmit include/linux/netdevice.h:3104 [inline] neigh_hh_output include/net/neighbour.h:526 [inline] neigh_output include/net/neighbour.h:540 [inline] ip6_finish_output2+0xfc2/0x1680 net/ipv6/ip6_output.c:137 ip6_finish_output+0x41e/0x810 net/ipv6/ip6_output.c:222 NF_HOOK include/linux/netfilter.h:314 [inline] ip6_xmit+0xefe/0x17f0 net/ipv6/ip6_output.c:358 inet6_csk_xmit+0x468/0x710 net/ipv6/inet6_connection_sock.c:135 __tcp_transmit_skb+0x1ed1/0x3b30 net/ipv4/tcp_output.c:1466 tcp_transmit_skb net/ipv4/tcp_output.c:1484 [inline] tcp_write_xmit+0x18b4/0x6a10 net/ipv4/tcp_output.c:2829 __tcp_push_pending_frames+0x9b/0x360 net/ipv4/tcp_output.c:3014 tcp_push_pending_frames include/net/tcp.h:2106 [inline] tcp_data_snd_check net/ipv4/tcp_input.c:5686 [inline] tcp_rcv_established+0x1111/0x2020 net/ipv4/tcp_input.c:6114 tcp_v6_do_rcv+0x5c8/0x13a0 net/ipv6/tcp_ipv6.c:1640 sk_backlog_rcv include/net/sock.h:1111 [inline] __release_sock+0x1c8/0x350 net/core/sock.c:3004 release_sock+0x61/0x1f0 net/core/sock.c:3558 tcp_sendmsg+0x3a/0x50 net/ipv4/tcp.c:1355 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0xef/0x270 net/socket.c:745 sock_sendmsg+0x134/0x200 net/socket.c:768 splice_to_socket+0xa13/0x10b0 fs/splice.c:889 do_splice_from fs/splice.c:941 [inline] direct_splice_actor+0x11e/0x220 fs/splice.c:1164 splice_direct_to_actor+0x58e/0xc90 fs/splice.c:1108 do_splice_direct_actor fs/splice.c:1207 [inline] do_splice_direct+0x28c/0x3e0 fs/splice.c:1233 do_sendfile+0x56d/0xe20 fs/read_write.c:1295 __do_sys_sendfile64 fs/read_write.c:1362 [inline] __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1348 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f45fb975bd9 RSP: 002b:00007f45fc6e3048 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f45fbb04038 RCX: 00007f45fb975bd9 RDX: 0000000000000000 RSI: 000000000000000d RDI: 000000000000000c RBP: 00007f45fb9e4aa1 R08: 0000000000000000 R09: 0000000000000000 R10: 000000008000002b R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f45fbb04038 R15: 00007ffd81d69c58 rcu: rcu_preempt kthread starved for 10371 jiffies! g18165 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:25744 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5248 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6600 __schedule_loop kernel/sched/core.c:6677 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6692 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2034 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2236 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.10.0-rc6-next-20240703-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:92 [inline] RIP: 0010:acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:113 Code: 90 90 90 90 90 90 90 90 90 65 48 8b 04 25 40 d7 03 00 48 f7 00 08 00 00 00 75 10 66 90 0f 00 2d 85 c7 98 00 f3 0f 1e fa fb f4 c3 cc cc cc cc 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 RSP: 0018:ffffffff8e007ca8 EFLAGS: 00000246 RAX: ffffffff8e094680 RBX: ffff88801bae1864 RCX: 000000000007e881 RDX: 0000000000000001 RSI: ffff88801bae1800 RDI: ffff88801bae1864 RBP: 000000000003a6b8 R08: ffff8880b9437c9b R09: 1ffff11017286f93 R10: dffffc0000000000 R11: ffffffff8b915050 R12: ffff88801bb3a000 R13: 0000000000000000 R14: 0000000000000001 R15: ffffffff8ead8980 FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000559ad9cd7008 CR3: 00000000291fa000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: acpi_idle_enter+0xe4/0x140 drivers/acpi/processor_idle.c:707 cpuidle_enter_state+0x112/0x480 drivers/cpuidle/cpuidle.c:267 cpuidle_enter+0x5d/0xa0 drivers/cpuidle/cpuidle.c:388 call_cpuidle kernel/sched/idle.c:155 [inline] cpuidle_idle_call kernel/sched/idle.c:230 [inline] do_idle+0x375/0x5d0 kernel/sched/idle.c:326 cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:424 rest_init+0x2dc/0x300 init/main.c:747 start_kernel+0x47a/0x500 init/main.c:1103 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:507 x86_64_start_kernel+0x9f/0xa0 arch/x86/kernel/head64.c:488 common_startup_64+0x13e/0x147