[v5.15] INFO: rcu detected stall in ktime_get_with_offset

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: cc5ec8769306 Linux 5.15.196
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1391d812580000
kernel config: https://syzkaller.appspot.com/x/.config?x=e1bb6d24ef2164eb
dashboard link: https://syzkaller.appspot.com/bug?extid=d3be42a8de0e87335422
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ed7568bc5bb4/disk-cc5ec876.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e343e0aaac77/vmlinux-cc5ec876.xz
kernel image: https://storage.googleapis.com/syzbot-assets/089870f2a980/bzImage-cc5ec876.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d3be42...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-...!: (1 GPs behind) idle=e73/1/0x4000000000000000 softirq=26828/26829 fqs=0
(t=10500 jiffies g=34045 q=94)
rcu: rcu_preempt kthread starved for 10500 jiffies! g34045 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:27136 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
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: 9673 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
RIP: 0010:kvm_wait+0x141/0x190 arch/x86/kernel/kvm.c:918
Code: 89 df 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 75 47 0f b6 1f e8 1f e2 49 00 44 38 e3 75 10 66 90 0f 00 2d 01 69 d4 08 fb f4 <e9> 33 ff ff ff fb e9 2d ff ff ff e8 df 65 75 08 89 f9 80 e1 07 38
RSP: 0018:ffffc90002d9eea0 EFLAGS: 00000246
RAX: 70500e9a75811000 RBX: 0000000000000003 RCX: 70500e9a75811000
RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: ffffffff8a59e580
RBP: ffffc90002d9ef50 R08: dffffc0000000000 R09: fffffbfff1ff7c19
R10: fffffbfff1ff7c19 R11: 1ffffffff1ff7c18 R12: 0000000000000003
R13: ffff8880b913b154 R14: dffffc0000000000 R15: 1ffff920005b3dd4
FS: 00005555746e9500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcf71de22f8 CR3: 00000000197a4000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
<TASK>
pv_wait arch/x86/include/asm/paravirt.h:597 [inline]
pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
__pv_queued_spin_lock_slowpath+0x60f/0x9c0 kernel/locking/qspinlock.c:508
pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:585 [inline]
queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51
queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
do_raw_spin_lock+0x217/0x280 kernel/locking/spinlock_debug.c:115
spin_lock include/linux/spinlock.h:364 [inline]
alloc_vmap_area+0x1948/0x1b20 mm/vmalloc.c:1564
__get_vm_area_node+0x14f/0x2d0 mm/vmalloc.c:2430
__vmalloc_node_range+0xef/0x8b0 mm/vmalloc.c:3027
__vmalloc_node mm/vmalloc.c:3087 [inline]
vzalloc+0x75/0x80 mm/vmalloc.c:3157
alloc_counters+0xd0/0x740 net/ipv4/netfilter/arp_tables.c:659
copy_entries_to_user net/ipv4/netfilter/arp_tables.c:680 [inline]
get_entries net/ipv4/netfilter/arp_tables.c:866 [inline]
do_arpt_get_ctl+0x9b2/0xf40 net/ipv4/netfilter/arp_tables.c:1460
nf_getsockopt+0x25e/0x280 net/netfilter/nf_sockopt.c:116
ip_getsockopt+0x115a/0x1590 net/ipv4/ip_sockglue.c:1797
tcp_getsockopt+0x1e3/0x2390 net/ipv4/tcp.c:4319
__sys_getsockopt+0x1b0/0x230 net/socket.c:2257
__do_sys_getsockopt net/socket.c:2272 [inline]
__se_sys_getsockopt net/socket.c:2269 [inline]
__x64_sys_getsockopt+0xb1/0xc0 net/socket.c:2269
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fcf71bc240a
Code: ff c3 66 0f 1f 44 00 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb b8 0f 1f 44 00 00 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 a8 ff ff ff f7
RSP: 002b:00007fffb06ef9d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000037
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fcf71bc240a
RDX: 0000000000000061 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007fffb06efa40 R08: 00007fffb06ef9ec R09: 00007fffb06efdd7
R10: 00007fffb06efa40 R11: 0000000000000212 R12: 00007fffb06ef9ec
R13: 00000000000927c0 R14: 000000000006c92a R15: 00007fffb06f0120
</TASK>
NMI backtrace for cpu 0
CPU: 0 PID: 10573 Comm: syz.3.1983 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
<IRQ>
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
rcu_dump_cpu_stacks+0x22f/0x380 kernel/rcu/tree_stall.h:349
print_cpu_stall+0x31d/0x5f0 kernel/rcu/tree_stall.h:633
check_cpu_stall kernel/rcu/tree_stall.h:727 [inline]
rcu_pending kernel/rcu/tree.c:3936 [inline]
rcu_sched_clock_irq+0x6d8/0x1110 kernel/rcu/tree.c:2619
update_process_times+0x193/0x200 kernel/time/timer.c:1818
tick_sched_handle kernel/time/tick-sched.c:254 [inline]
tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:seqcount_lockdep_reader_access+0x17b/0x1c0 include/linux/seqlock.h:106
Code: 00 4d 85 e4 75 16 e8 54 cc 0f 00 eb 15 e8 4d cc 0f 00 e8 18 6e 41 08 4d 85 e4 74 ea e8 3e cc 0f 00 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 3e 00 00 00 00 66 43 c7 44 3e 09 00 00 43 c6 44 3e 0b 00
RSP: 0018:ffffc900000075a0 EFLAGS: 00000246
RAX: ffffffff8167ffd2 RBX: 0000000000000000 RCX: ffff8880204a3b80
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000007658 R08: dffffc0000000000 R09: fffffbfff1ff7c19
R10: fffffbfff1ff7c19 R11: 1ffffffff1ff7c18 R12: 0000000000000200
R13: 000001fb63109b96 R14: 1ffff92000000eb4 R15: dffffc0000000000
timekeeping_get_delta kernel/time/timekeeping.c:254 [inline]
timekeeping_get_ns kernel/time/timekeeping.c:388 [inline]
ktime_get_with_offset+0xff/0x320 kernel/time/timekeeping.c:874
ktime_get_real include/linux/timekeeping.h:79 [inline]
__net_timestamp include/linux/skbuff.h:3970 [inline]
netif_receive_skb_list_internal+0x30c/0xb90 net/core/dev.c:5737
gro_normal_list net/core/dev.c:5913 [inline]
gro_normal_one net/core/dev.c:5926 [inline]
napi_skb_finish net/core/dev.c:6263 [inline]
napi_gro_receive+0x4ef/0xa60 net/core/dev.c:6293
receive_buf+0x3793/0x5780 drivers/net/virtio_net.c:1240
virtnet_receive drivers/net/virtio_net.c:1504 [inline]
virtnet_poll+0x546/0xef0 drivers/net/virtio_net.c:1617
__napi_poll+0xc0/0x430 net/core/dev.c:7075
napi_poll net/core/dev.c:7142 [inline]
net_rx_action+0x4a8/0x9c0 net/core/dev.c:7232
handle_softirqs+0x328/0x820 kernel/softirq.c:576
__do_softirq kernel/softirq.c:610 [inline]
invoke_softirq kernel/softirq.c:450 [inline]
__irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
common_interrupt+0xb5/0xd0 arch/x86/kernel/irq.c:242
</IRQ>
<TASK>
asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:667
RIP: 0010:__find_vmap_area mm/vmalloc.c:839 [inline]
RIP: 0010:find_vmap_area mm/vmalloc.c:1793 [inline]
RIP: 0010:find_vm_area mm/vmalloc.c:2492 [inline]
RIP: 0010:__vunmap+0x88/0xa40 mm/vmalloc.c:2606
Code: 6c 24 2c 49 bd 00 00 00 00 00 fc ff df 4d 8d 7e f0 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 5b 3a 0b 00 4d 8b 3f <4c> 89 ff 48 89 de e8 0d d4 c6 ff 49 39 df 76 0c e8 23 d2 c6 ff b8
RSP: 0018:ffffc90002f6f4d0 EFLAGS: 00000246
RAX: 1ffff11003cdc520 RBX: ffffc90000cde000 RCX: 0000000000080000
RDX: ffffc9000c521000 RSI: 00000000000115c0 RDI: 00000000000115c1
RBP: 0000000000000001 R08: 0000000000000004 R09: 0000000000000003
R10: fffff520005ede88 R11: 1ffff920005ede88 R12: 0000000000000018
R13: dffffc0000000000 R14: ffff88801e6e2910 R15: ffffc90004d28000
adjust_insn_aux_data kernel/bpf/verifier.c:12074 [inline]
bpf_patch_insn_data+0x788/0xe60 kernel/bpf/verifier.c:12127
convert_ctx_accesses kernel/bpf/verifier.c:12669 [inline]
bpf_check+0x5738/0xf090 kernel/bpf/verifier.c:14166
bpf_prog_load+0x1043/0x1550 kernel/bpf/syscall.c:2354
__sys_bpf+0x4c2/0x670 kernel/bpf/syscall.c:4657
__do_sys_bpf kernel/bpf/syscall.c:4761 [inline]
__se_sys_bpf kernel/bpf/syscall.c:4759 [inline]
__x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4759
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f3be8df06c9
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:00007f3be7057038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f3be9046fa0 RCX: 00007f3be8df06c9
RDX: 0000000000000048 RSI: 000020000000e000 RDI: 0000000000000005
RBP: 00007f3be8e72f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3be9047038 R14: 00007f3be9046fa0 R15: 00007fffb15a6a88
</TASK>


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