rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6452/1:b..l rcu: (detected by 0, t=10503 jiffies, g=172261, q=980 ncpus=2) task:syz.7.8272 state:R running task stack:22944 pid:6452 tgid:6447 ppid:28931 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 kernel/sched/core.c:6756 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7078 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:unwind_get_return_address+0x56/0x90 arch/x86/kernel/unwind_orc.c:369 Code: 83 c3 48 49 89 df 49 c1 ef 03 43 80 3c 37 00 74 08 48 89 df e8 9b 2b ba 00 48 8b 3b e8 e3 71 1e 00 85 c0 74 14 43 80 3c 37 00 <74> 08 48 89 df e8 80 2b ba 00 48 8b 03 eb 02 31 c0 5b 41 5e 41 5f RSP: 0018:ffffc9000d1d6e00 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffffc9000d1d6e68 RCX: ffffffff91795000 RDX: ffffffff91945b01 RSI: ffffc9000d1d0000 RDI: ffffffff8989b87a RBP: ffffc9000d1d6eb0 R08: ffffc9000d1d7af0 R09: ffffc9000d1d6e70 R10: dffffc0000000000 R11: fffff52001a3add0 R12: ffff888026d15a00 R13: ffffffff818b3ba0 R14: dffffc0000000000 R15: 1ffff92001a3adcd arch_stack_walk+0xfd/0x150 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4119 [inline] slab_alloc_node mm/slub.c:4168 [inline] kmem_cache_alloc_node_noprof+0x1d9/0x380 mm/slub.c:4220 __alloc_skb+0x1c3/0x440 net/core/skbuff.c:668 alloc_skb include/linux/skbuff.h:1323 [inline] ip6_frag_next+0x12c/0xc60 net/ipv6/ip6_output.c:804 ip6_fragment+0x15b4/0x22c0 net/ipv6/ip6_output.c:1018 __ip6_finish_output net/ipv6/ip6_output.c:213 [inline] ip6_finish_output+0x2b8/0x840 net/ipv6/ip6_output.c:226 ip6_send_skb+0x1b1/0x3b0 net/ipv6/ip6_output.c:1976 rawv6_push_pending_frames+0x75c/0x9e0 net/ipv6/raw.c:588 rawv6_sendmsg+0x19c2/0x23d0 net/ipv6/raw.c:926 sock_sendmsg_nosec net/socket.c:711 [inline] __sock_sendmsg+0x1a6/0x270 net/socket.c:726 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2583 ___sys_sendmsg net/socket.c:2637 [inline] __sys_sendmsg+0x269/0x350 net/socket.c:2669 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: 0033:0x7fdc91b85d29 RSP: 002b:00007fdc92a0f038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fdc91d76080 RCX: 00007fdc91b85d29 RDX: 0000000000000004 RSI: 00000000200000c0 RDI: 0000000000000007 RBP: 00007fdc91c01b08 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fdc91d76080 R15: 00007fff0224b558 rcu: rcu_preempt kthread starved for 1147 jiffies! g172261 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:25072 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6451 Comm: syz.7.8272 Not tainted 6.13.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:142 [inline] RIP: 0010:lock_acquire+0x1b7/0x550 kernel/locking/lockdep.c:5850 Code: 08 4c 89 ff e8 da 30 8b 00 48 8d 5c 24 60 4c 8b bc 24 80 00 00 00 fa 48 c7 c7 80 a5 0a 8c e8 80 57 4e 0a 65 ff 05 b9 d8 87 7e <45> 31 c9 41 f7 c7 00 02 00 00 41 0f 94 c1 48 8b 7c 24 20 44 89 f6 RSP: 0018:ffffc9000cebf8a0 EFLAGS: 00000002 RAX: 0000000000000001 RBX: ffffc9000cebf900 RCX: ffffffff817ab0e4 RDX: 0000000000000000 RSI: ffffffff8c0aa580 RDI: ffffffff8c5fd460 RBP: ffffc9000cebf9e8 R08: ffffffff9019b137 R09: 1ffffffff2033626 R10: dffffc0000000000 R11: fffffbfff2033627 R12: 1ffff920019d7f1c R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000046 FS: 00007fdc92a306c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005650b163a600 CR3: 00000000374ea000 CR4: 0000000000350ef0 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] percpu_ref_get_many+0x36/0x140 include/linux/percpu-refcount.h:202 percpu_ref_get include/linux/percpu-refcount.h:222 [inline] obj_cgroup_get include/linux/memcontrol.h:768 [inline] __memcg_slab_post_alloc_hook+0x44f/0x7e0 mm/memcontrol.c:3011 memcg_slab_post_alloc_hook mm/slub.c:2152 [inline] slab_post_alloc_hook mm/slub.c:4129 [inline] slab_alloc_node mm/slub.c:4168 [inline] kmem_cache_alloc_noprof+0x287/0x380 mm/slub.c:4175 sigqueue_alloc kernel/signal.c:454 [inline] __send_signal_locked+0x245/0xe90 kernel/signal.c:1086 do_send_sig_info kernel/signal.c:1268 [inline] group_send_sig_info+0x292/0x310 kernel/signal.c:1418 bpf_send_signal_common+0x3c4/0x630 kernel/trace/bpf_trace.c:881 ____bpf_send_signal kernel/trace/bpf_trace.c:886 [inline] bpf_send_signal+0x1d/0x30 kernel/trace/bpf_trace.c:884 bpf_prog_7ba5217f62dcd359+0x41/0x49 bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2362 [inline] bpf_trace_run2+0x2ee/0x540 kernel/trace/bpf_trace.c:2403 __bpf_trace_sys_enter+0x38/0x60 include/trace/events/syscalls.h:18 trace_sys_enter+0xb0/0x120 include/trace/events/syscalls.h:18 syscall_trace_enter+0xf8/0x150 kernel/entry/common.c:61 syscall_enter_from_user_mode_work include/linux/entry-common.h:169 [inline] syscall_enter_from_user_mode include/linux/entry-common.h:199 [inline] do_syscall_64+0xcc/0x230 arch/x86/entry/common.c:79 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdc91b21f29 Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25 RSP: 002b:00007fdc92a2fb40 EFLAGS: 00000246 ORIG_RAX: 000000000000000f RAX: ffffffffffffffda RBX: 00007fdc91d75fa8 RCX: 00007fdc91b21f29 RDX: 00007fdc92a2fb40 RSI: 00007fdc92a2fc70 RDI: 0000000000000011 RBP: 00007fdc91d75fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fdc91d75fac R13: 0000000000000000 R14: 00007fff0224b470 R15: 00007fff0224b558