rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6207/1:b..l rcu: (detected by 0, t=10503 jiffies, g=19869, q=954 ncpus=2) task:syz.4.124 state:R running task stack:23568 pid:6207 tgid:6180 ppid:5455 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6851 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:rcu_read_unlock include/linux/rcupdate.h:867 [inline] RIP: 0010:count_memcg_event_mm+0x334/0x420 include/linux/memcontrol.h:1021 Code: c2 65 b2 ff 4c 8b 6c 24 18 eb 1f e8 b6 65 b2 ff e8 91 83 d8 09 4d 85 f6 74 84 e8 a7 65 b2 ff fb 49 be 00 00 00 00 00 fc ff df 17 8a d8 09 89 c3 31 ff 89 c6 e8 cc 69 b2 ff 85 db 74 10 e8 b3 RSP: 0018:ffffc900054273a0 EFLAGS: 00000246 RAX: ffffffff81e12709 RBX: 0000000000000000 RCX: 0000000000040000 RDX: ffffc9000e0a4000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: ffffc90005427470 R08: ffffffff81e12679 R09: 1ffffffff283c90e R10: dffffc0000000000 R11: fffffbfff283c90f R12: 0000000000000046 R13: ffffffff81e12474 R14: dffffc0000000000 R15: 1ffff92000a84e78 mm_account_fault mm/memory.c:5698 [inline] handle_mm_fault+0x16f7/0x1bc0 mm/memory.c:5858 faultin_page mm/gup.c:1194 [inline] __get_user_pages+0x6ec/0x16a0 mm/gup.c:1493 __get_user_pages_locked mm/gup.c:1760 [inline] faultin_page_range+0x204/0x850 mm/gup.c:1984 madvise_populate mm/madvise.c:943 [inline] do_madvise+0x60d/0x4760 mm/madvise.c:1464 __do_sys_madvise mm/madvise.c:1484 [inline] __se_sys_madvise mm/madvise.c:1482 [inline] __x64_sys_madvise+0xa6/0xc0 mm/madvise.c:1482 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: 0033:0x7f164137cef9 RSP: 002b:00007f1640dff038 EFLAGS: 00000246 ORIG_RAX: 000000000000001c RAX: ffffffffffffffda RBX: 00007f1641536208 RCX: 00007f164137cef9 RDX: 0000000000000017 RSI: 0000000000800000 RDI: 00000000200ec000 RBP: 00007f16413ef046 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f1641536208 R15: 00007ffe53081188 rcu: rcu_preempt kthread starved for 251 jiffies! g19869 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:25328 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 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+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: 6212 Comm: syz.2.132 Not tainted 6.11.0-rc6-syzkaller-00308-gb31c44928842 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:__sanitizer_cov_trace_pc+0x5d/0x70 kernel/kcov.c:234 Code: f8 15 00 00 83 fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc 15 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 f9 b3 5c 0a 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 90 90 RSP: 0018:ffffc90009777600 EFLAGS: 00000046 RAX: ffffffff814145ab RBX: ffffc90009778000 RCX: 0000000000040000 RDX: ffffc9001b8f2000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: ffffc900097776e0 R08: ffffffff81414545 R09: ffffffff814140bf R10: 0000000000000003 R11: ffff88802664bc00 R12: ffffc90009777a98 R13: dffffc0000000000 R14: ffffc90009770000 R15: ffffc90009777aa0 FS: 00007f6ada5b86c0(0000) GS:ffff8880b8900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6ada5b8040 CR3: 000000006d93c000 CR4: 0000000000350ef0 Call Trace: unwind_next_frame+0x1e5b/0x2a00 arch/x86/kernel/unwind_orc.c:665 arch_stack_walk+0x151/0x1b0 arch/x86/kernel/stacktrace.c:25 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 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2256 [inline] slab_free mm/slub.c:4477 [inline] kmem_cache_free+0x145/0x350 mm/slub.c:4552 __sigqueue_free kernel/signal.c:451 [inline] collect_signal kernel/signal.c:594 [inline] __dequeue_signal+0x4ac/0x5c0 kernel/signal.c:616 dequeue_signal+0x169/0x5a0 kernel/signal.c:639 get_signal+0x602/0x1740 kernel/signal.c:2796 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6ad977cef9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f6ada5b80e8 EFLAGS: 00000246 RAX: fffffffffffffffc RBX: 00007f6ad9936138 RCX: 00007f6ad977cef9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f6ad9936138 RBP: 00007f6ad9936130 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6ad993613c R13: 0000000000000000 R14: 00007fff76194bc0 R15: 00007fff76194ca8