rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=8554/1/0x4000000000000000 softirq=21519/21520 fqs=13 (t=10501 jiffies g=28133 q=32 ncpus=2) rcu: rcu_preempt kthread starved for 10472 jiffies! g28133 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:26688 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x142d/0x4550 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 7264 Comm: syz-executor.2 Not tainted 6.1.92-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 RIP: 0010:copy_page_to_iter_pipe+0x244/0x840 lib/iov_iter.c:329 Code: 84 c0 0f 85 5b 03 00 00 45 8b b7 34 01 00 00 49 8d 9f 38 01 00 00 48 89 d8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 59 03 00 00 <8b> 1b 89 d5 44 29 f5 89 ef 89 de 49 89 d4 e8 c9 22 54 fd 39 dd 0f RSP: 0018:ffffc9000399f4f8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff888016a9d538 RCX: 0000000000040000 RDX: 0000000000000007 RSI: 000000000003ffff RDI: ffff888016a9d534 RBP: ffffc9000399f990 R08: ffffffff84366a76 R09: fffff940002993b1 R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: 1ffff11002d53aa6 R14: 0000000000000000 R15: ffff888016a9d400 FS: 00007f434dc836c0(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3394c000 CR3: 0000000042443000 CR4: 00000000003526e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: copy_folio_to_iter include/linux/uio.h:172 [inline] filemap_read+0x273e/0x31d0 mm/filemap.c:2790 call_read_iter include/linux/fs.h:2259 [inline] generic_file_splice_read+0x23c/0x630 fs/splice.c:308 do_splice_to fs/splice.c:803 [inline] splice_direct_to_actor+0x405/0xc30 fs/splice.c:875 do_splice_direct+0x2a5/0x3e0 fs/splice.c:1002 do_sendfile+0x61c/0xff0 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1323 [inline] __se_sys_sendfile64+0x178/0x1e0 fs/read_write.c:1309 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f434ce7cf69 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f434dc830c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f434cfb41f0 RCX: 00007f434ce7cf69 RDX: 0000000000000000 RSI: 0000000000000007 RDI: 0000000000000006 RBP: 00007f434ceda6fe R08: 0000000000000000 R09: 0000000000000000 R10: 000000008000002b R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f434cfb41f0 R15: 00007ffe105cff78 CPU: 0 PID: 15 Comm: ksoftirqd/0 Not tainted 6.1.92-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 RIP: 0010:finish_task_switch+0x1d3/0x810 kernel/sched/core.c:5124 Code: 37 0b 00 48 83 c4 08 4c 89 f7 e8 98 30 00 00 0f 1f 44 00 00 4c 89 f7 e8 7b 20 36 09 e8 36 26 32 00 fb 49 8d bc 24 f8 15 00 00 <48> 89 f8 48 c1 e8 03 49 bd 00 00 00 00 00 fc ff df 42 0f b6 04 28 RSP: 0018:ffffc90000147aa8 EFLAGS: 00000286 RAX: a9b2750567484a00 RBX: ffff88801eee0034 RCX: ffffffff91c94103 RDX: dffffc0000000000 RSI: ffffffff8aec01c0 RDI: ffff88813feed178 RBP: ffffc90000147af0 R08: dffffc0000000000 R09: ffffed1017307541 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88813feebb80 R13: 1ffff110173076eb R14: ffff8880b983aa00 R15: ffff8880b983b758 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f493b5ded58 CR3: 0000000042443000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: context_switch kernel/sched/core.c:5248 [inline] __schedule+0x1435/0x4550 kernel/sched/core.c:6558 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:preempt_count_add+0x0/0x180 kernel/sched/core.c:5698 Code: 48 8b 0c 24 80 e1 07 80 c1 03 38 c1 7c 97 48 8b 3c 24 e8 83 ba 83 00 eb 8c e9 f2 fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 66 90 <41> 57 41 56 53 89 fb 48 c7 c0 60 41 c9 91 48 c1 e8 03 49 bf 00 00 RSP: 0018:ffffc90000147e48 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 1ffff11027fdd770 RCX: ffffffff8a938926 RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000001 RBP: ffff88813feed2e8 R08: dffffc0000000000 R09: ffffed1027fdd771 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88813feebb80 R13: ffffffff8cfcf300 R14: ffff88813feecdf8 R15: dffffc0000000000 schedule+0xb8/0x180 kernel/sched/core.c:6633 smpboot_thread_fn+0x604/0xa30 kernel/smpboot.c:160 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308