Hello,
syzbot found the following issue on:
HEAD commit: fdb6fcb41cc7 Linux 6.1.176
git tree: linux-6.1.y
console output:
https://syzkaller.appspot.com/x/log.txt?x=148bf61c580000
kernel config:
https://syzkaller.appspot.com/x/.config?x=acfbe65fbce84c0c
dashboard link:
https://syzkaller.appspot.com/bug?extid=e3a50322dcc0651cfbd4
compiler: Debian clang version 22.1.6 (++20260514074242+fc4aad7b5db3-1~exp1~20260514074407.73), Debian LLD 22.1.6
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image:
https://storage.googleapis.com/syzbot-assets/8a12ae1ddcea/disk-fdb6fcb4.raw.xz
vmlinux:
https://storage.googleapis.com/syzbot-assets/d0dd1b27df77/vmlinux-fdb6fcb4.xz
kernel image:
https://storage.googleapis.com/syzbot-assets/871bf60ea1f2/bzImage-fdb6fcb4.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by:
syzbot+e3a503...@syzkaller.appspotmail.com
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 2910 jiffies s: 1049 root: 0x1/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4378 Comm: syz.1.2 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline]
RIP: 0010:mark_lock+0x9c/0x320 kernel/locking/lockdep.c:4606
Code: 89 c7 41 81 e7 ff 1f 00 00 c1 e8 03 25 f8 03 00 00 48 8d b8 40 22 af 90 be 08 00 00 00 e8 0c 9d 6e 00 4c 0f a3 3d e4 74 4a 0f <73> 10 4b 8d 04 7f c1 e0 06 4c 8d b8 00 a1 47 90 eb 24 48 c7 c0 40
RSP: 0018:ffffc90000006ce0 EFLAGS: 00000057
RAX: 0000000000000001 RBX: ffff888073111e00 RCX: ffffffff8164ad54
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90af2250
RBP: 0000000000000004 R08: ffffffff90af2257 R09: 1ffffffff215e44a
R10: dffffc0000000000 R11: fffffbfff215e44b R12: 0000000000000010
R13: dffffc0000000000 R14: ffff8880731129f8 R15: 00000000000000b5
FS: 00007f3c0e7706c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3a9d9ec000 CR3: 0000000028768000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
<IRQ>
mark_usage kernel/locking/lockdep.c:-1 [inline]
__lock_acquire+0xc6b/0x7bd0 kernel/locking/lockdep.c:5003
lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162
hrtimer_interrupt+0xf4/0x980 kernel/time/hrtimer.c:1858
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
__sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
sysvec_apic_timer_interrupt+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1118
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:seqcount_lockdep_reader_access+0x144/0x190 include/linux/seqlock.h:105
Code: 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 42 41 f7 c5 00 02 00 00 74 01 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 27 00 00 00 00 43 c7 44 27 08 00 00 00 00 65 48 8b 04 25
RSP: 0018:ffffc90000007340 EFLAGS: 00000206
RAX: dffffc0000000004 RBX: ffff88813fffa7c8 RCX: 1653406c72b26000
RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: ffffffff8adee1a0
RBP: ffffc900000073f0 R08: ffffffff90af2337 R09: 1ffffffff215e466
R10: dffffc0000000000 R11: fffffbfff215e467 R12: dffffc0000000000
R13: 0000000000000a02 R14: ffffffff81c8aeb9 R15: 1ffff92000000e68
read_seqbegin include/linux/seqlock.h:893 [inline]
zone_span_seqbegin include/linux/memory_hotplug.h:132 [inline]
page_outside_zone_boundaries mm/page_alloc.c:654 [inline]
bad_range+0x79/0x2c0 mm/page_alloc.c:681
rmqueue mm/page_alloc.c:3917 [inline]
get_page_from_freelist+0x2052/0x2180 mm/page_alloc.c:4355
__alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5658
alloc_slab_page+0x5d/0x180 mm/slub.c:1799
allocate_slab mm/slub.c:1944 [inline]
new_slab+0x87/0x2d0 mm/slub.c:1997
___slab_alloc+0xbc5/0x1240 mm/slub.c:3154
__slab_alloc mm/slub.c:3240 [inline]
slab_alloc_node mm/slub.c:3325 [inline]
slab_alloc mm/slub.c:3367 [inline]
__kmem_cache_alloc_lru mm/slub.c:3374 [inline]
kmem_cache_alloc+0x111/0x2f0 mm/slub.c:3383
skb_clone+0x1e7/0x370 net/core/skbuff.c:1660
hsr_forward_do net/hsr/hsr_forward.c:-1 [inline]
hsr_forward_skb+0xf11/0x20c0 net/hsr/hsr_forward.c:626
send_hsr_supervision_frame+0x5f7/0xb90 net/hsr/hsr_device.c:346
hsr_announce+0x194/0x340 net/hsr/hsr_device.c:402
call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701
expire_timers kernel/time/timer.c:1752 [inline]
__run_timers+0x56c/0x810 kernel/time/timer.c:2023
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036
handle_softirqs+0x291/0x910 kernel/softirq.c:596
__do_softirq kernel/softirq.c:630 [inline]
invoke_softirq kernel/softirq.c:470 [inline]
__irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679
irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:lock_is_held_type+0x13a/0x190 kernel/locking/lockdep.c:5710
Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c5 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffffc90004596e58 EFLAGS: 00000206
RAX: 1653406c72b26000 RBX: ffff888073111e00 RCX: 1653406c72b26000
RDX: 0000000000000010 RSI: ffffffff8a8c2920 RDI: ffffffff8adee1a0
RBP: 0000000000000000 R08: ffffc90004596fcf R09: ffffc90004596fc0
R10: dffffc0000000000 R11: fffff520008b2dfa R12: 0000000000000003
R13: 0000000000000246 R14: ffffffff8cb2dbc0 R15: ffff888073112958
lock_is_held include/linux/lockdep.h:283 [inline]
schedule_debug kernel/sched/core.c:5823 [inline]
__schedule+0x1bf/0x4030 kernel/sched/core.c:6455
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:propagate_protected_usage+0x41/0x210 mm/page_counter.c:22
Code: fc ff df e8 91 9f a8 ff 4d 8d a6 a0 00 00 00 4c 89 e3 48 c1 eb 03 42 80 3c 2b 00 74 08 4c 89 e7 e8 34 c7 f9 ff 49 83 3c 24 00 <74> 7a 49 8d be 80 00 00 00 48 89 f8 48 c1 e8 03 42 80 3c 28 00 74
RSP: 0018:ffffc900045971a8 EFLAGS: 00000286
RAX: ffffffff81d9817f RBX: 1ffff1100eb4346c RCX: 0000000000080000
RDX: ffffc9000fb35000 RSI: 0000000000015f5d RDI: 0000000000015f5e
RBP: ffffc900045972f8 R08: ffff888075a1a2c7 R09: 1ffff1100eb43458
R10: dffffc0000000000 R11: ffffed100eb43459 R12: ffff888075a1a360
R13: dffffc0000000000 R14: ffff888075a1a2c0 R15: 000000000000008e
page_counter_charge+0x51/0x100 mm/page_counter.c:78
memcg_account_kmem+0x1a4/0x1c0 mm/memcontrol.c:3058
obj_cgroup_charge_pages mm/memcontrol.c:3103 [inline]
__memcg_kmem_charge_page+0x231/0x380 mm/memcontrol.c:3125
__alloc_pages+0x21e/0x4f0 mm/page_alloc.c:5675
pmd_alloc_one include/asm-generic/pgalloc.h:126 [inline]
__pmd_alloc+0xa6/0x760 mm/memory.c:5487
pmd_alloc include/linux/mm.h:2430 [inline]
copy_pmd_range mm/memory.c:1157 [inline]
copy_pud_range mm/memory.c:1214 [inline]
copy_p4d_range mm/memory.c:1238 [inline]
copy_page_range+0x35a6/0x3a60 mm/memory.c:1332
dup_mmap kernel/fork.c:703 [inline]
dup_mm kernel/fork.c:1547 [inline]
copy_mm+0xeb0/0x1680 kernel/fork.c:1596
copy_process+0x19a6/0x40c0 kernel/fork.c:2357
kernel_clone+0x24b/0x900 kernel/fork.c:2764
__do_sys_clone kernel/fork.c:2905 [inline]
__se_sys_clone kernel/fork.c:2889 [inline]
__x64_sys_clone+0x1a7/0x220 kernel/fork.c:2889
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: 0033:0x7f3c0d99ce59
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:00007f3c0e76ffd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f3c0dc16090 RCX: 00007f3c0d99ce59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000081084000
RBP: 00007f3c0da32e6f R08: 0000200000002380 R09: 0000200000002380
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f3c0dc16128 R14: 00007f3c0dc16090 R15: 00007ffe63de88d8
</TASK>
---
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