rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6698/1:b..l
(detected by 1, t=10506 jiffies, g=20001, q=1553 ncpus=2)
task:syz.0.787 state:R running task stack:25712 pid:6698 ppid:4272 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6874
irqentry_exit+0x63/0x70 kernel/entry/common.c:439
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:bpf_prog_831c9d8e015372e0+0x14/0x3f
Code: ff cc cc cc cc cc 80 00 00 00 cc cc cc cc cc cc cc cc cc cc cc cc 0f 1f 44 00 00 66 90 55 48 89 e5 48 81 ec 08 00 00 00 41 56 <31> c0 48 bf 00 48 fe 28 80 88 ff ff 45 31 f6 4c 89 75 f8 44 89 f6
RSP: 0018:ffffc9000e1cfa00 EFLAGS: 00000292
RAX: ffffffff883e45a3 RBX: ffffc9000e1cfc5c RCX: 0000000000080000
RDX: ffffffffa0000950 RSI: ffffc9000e273048 RDI: ffffc9000e1cfc80
RBP: ffffc9000e1cfa10 R08: ffffffff8fa0c008 R09: ffffffff8fa0c018
R10: ffffffff8fa0c010 R11: ffffffff8fa0c003 R12: ffffc9000e1cfc58
R13: ffffc9000e273030 R14: dffffc0000000000 R15: 0000000000000001
__bpf_prog_run include/linux/filter.h:596 [inline]
bpf_prog_run_xdp include/linux/filter.h:809 [inline]
bpf_test_run+0x58f/0x830 net/bpf/test_run.c:400
bpf_prog_test_run_xdp+0x70e/0xf10 net/bpf/test_run.c:1414
bpf_prog_test_run+0x31e/0x390 kernel/bpf/syscall.c:3695
__sys_bpf+0x62b/0x780 kernel/bpf/syscall.c:5049
__do_sys_bpf kernel/bpf/syscall.c:5135 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5133 [inline]
__x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5133
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f176439c819
RSP: 002b:00007f1765262028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f1764615fa0 RCX: 00007f176439c819
RDX: 0000000000000050 RSI: 0000200000000500 RDI: 000000000000000a
RBP: 00007f1764432c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1764616038 R14: 00007f1764615fa0 R15: 00007ffe7b6e8898
rcu: rcu_preempt kthread timer wakeup didn't happen for 10495 jiffies! g20001 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=13516
rcu: rcu_preempt kthread starved for 10496 jiffies! g20001 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27184 pid:16 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x303/0x1340 kernel/rcu/tree.c:1706
rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6713 Comm: syz.4.793 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:restore_regs_and_return_to_kernel+0x13/0x22
Code: ff 77 18 ff 77 10 ff 37 5f 0f 01 f8 66 90 0f 00 2d 95 f0 ff ff eb 1b 41 5f 41 5e 41 5d 41 5c 5d 5b 41 5b 41 5a 41 59 41 58 58 <59> 5a 5e 5f 48 83 c4 08 f6 44 24 20 04 75 02 48 cf 57 0f 01 f8 65
RSP: 0018:ffffc9000e1ffbb0 EFLAGS: 00000046
RAX: ac09b84619ffe900 RBX: 1ffff92001c3ff88 RCX: ac09b84619ffe900
RDX: dffffc0000000000 RSI: ffffffff8a8c10a0 RDI: ffffffff8adf0d20
RBP: ffffc9000e1ffcf8 R08: ffffffff90af724f R09: 1ffffffff215ee49
R10: dffffc0000000000 R11: fffffbfff215ee4a R12: 0000000000000246
R13: dffffc0000000000 R14: 0000000000000000 R15: ffffffff8cb32bd8
FS: 000055556f97a500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2e541a CR3: 0000000050b61000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
RIP: 0010:rcu_read_unlock_special+0x7f/0x510 kernel/rcu/tree_plugin.h:685
Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 d2 33 95 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc9000e1ffc00 EFLAGS: 00000206
RAX: ac09b84619ffe900 RBX: 1ffff92001c3ff88 RCX: ac09b84619ffe900
RDX: dffffc0000000000 RSI: ffffffff8a8c10a0 RDI: ffffffff8adf0d20
RBP: ffffc9000e1ffcf8 R08: ffffffff90af724f R09: 1ffffffff215ee49
R10: dffffc0000000000 R11: fffffbfff215ee4a R12: 0000000000000246
R13: dffffc0000000000 R14: 0000000000000000 R15: ffffffff8cb32bd8
__rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426
rcu_read_unlock+0x85/0xa0 include/linux/rcupdate.h:823
dput+0xe2/0x1d0 fs/dcache.c:911
__fput+0x5e0/0x920 fs/file_table.c:328
task_work_run+0x1d0/0x260 kernel/task_work.c:203
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4294f9c819
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc567edfb8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f4295217da0 RCX: 00007f4294f9c819
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f4295217da0 R08: 00007f4295216038 R09: 0000000000000000
R10: 00000000003ffcf4 R11: 0000000000000246 R12: 0000000000029fca
R13: 00007f429521609c R14: 0000000000029d35 R15: 00007f4295216090