[syzbot] [net?] WARNING in stack_depot_save_flags (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 70eda68668d1 Merge tag 'hid-for-linus-2026051401' of git:/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13291bce580000
kernel config: https://syzkaller.appspot.com/x/.config?x=59da38148f3a3d24
dashboard link: https://syzkaller.appspot.com/bug?extid=1827030ed7bc886dd0a5
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44

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

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-70eda686.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7c7af75df257/vmlinux-70eda686.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a8cc495201bd/bzImage-70eda686.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+182703...@syzkaller.appspotmail.com

------------[ cut here ]------------
Stack depot reached limit capacity
WARNING: lib/stackdepot.c:302 at depot_init_pool lib/stackdepot.c:302 [inline], CPU#0: kworker/u32:17/13749
WARNING: lib/stackdepot.c:302 at depot_pop_free_pool lib/stackdepot.c:371 [inline], CPU#0: kworker/u32:17/13749
WARNING: lib/stackdepot.c:302 at depot_alloc_stack lib/stackdepot.c:462 [inline], CPU#0: kworker/u32:17/13749
WARNING: lib/stackdepot.c:302 at stack_depot_save_flags+0x9a2/0x9d0 lib/stackdepot.c:706, CPU#0: kworker/u32:17/13749
Modules linked in:
CPU: 0 UID: 0 PID: 13749 Comm: kworker/u32:17 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: netns cleanup_net
RIP: 0010:depot_init_pool lib/stackdepot.c:302 [inline]
RIP: 0010:depot_pop_free_pool lib/stackdepot.c:371 [inline]
RIP: 0010:depot_alloc_stack lib/stackdepot.c:462 [inline]
RIP: 0010:stack_depot_save_flags+0x9a2/0x9d0 lib/stackdepot.c:706
Code: 0b 90 eb bf 48 85 ed 74 c6 48 89 2d a0 de 17 16 48 89 ea 31 ed e9 0b ff ff ff 39 c1 72 1f 48 85 d2 74 20 48 8d 3d ae e6 b3 0b <67> 48 0f b9 3a 45 31 f6 48 85 ed 0f 85 37 fa ff ff eb 92 90 0f 0b
RSP: 0018:ffffc900000072e0 EFLAGS: 00010086
RAX: 0000000000002000 RBX: 0000000000000000 RCX: 0000000000002000
RDX: ffff8880460f8000 RSI: ffffffff8defc944 RDI: ffffffff90e25c00
RBP: 0000000000000000 R08: 000000001c62ad74 R09: 000000002f4d0daf
R10: 0000000000000150 R11: 0000000000000000 R12: ffffc90000007338
R13: 0000000000000025 R14: ffff88816d70daf0 R15: ffff88816d70daf0
FS: 0000000000000000(0000) GS:ffff8880d6370000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555c1b6ff300 CR3: 000000000e596000 CR4: 0000000000352ef0
Call Trace:
<IRQ>
kasan_save_stack+0x3f/0x50 mm/kasan/common.c:58
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2689 [inline]
slab_free mm/slub.c:6250 [inline]
kmem_cache_free+0x127/0x6c0 mm/slub.c:6377
kfree_skbmem+0x19a/0x210 net/core/skbuff.c:1137
__kfree_skb net/core/skbuff.c:1204 [inline]
sk_skb_reason_drop+0x10f/0x1b0 net/core/skbuff.c:1241
packet_rcv+0x16c/0x17b0 net/packet/af_packet.c:2224
dev_queue_xmit_nit+0x6fc/0xa60 net/core/dev.c:2606
xmit_one net/core/dev.c:3884 [inline]
dev_hard_start_xmit+0x2fc/0x7a0 net/core/dev.c:3904
__dev_queue_xmit+0x1baa/0x4950 net/core/dev.c:4870
lapb_data_transmit+0x96/0xc0 net/lapb/lapb_iface.c:447
lapb_transmit_buffer+0xce/0x3a0 net/lapb/lapb_out.c:149
lapb_send_control+0x1ce/0x330 net/lapb/lapb_subr.c:251
lapb_establish_data_link+0xeb/0x110 net/lapb/lapb_out.c:163
lapb_state3_machine net/lapb/lapb_in.c:445 [inline]
lapb_data_input+0xc45/0x19d0 net/lapb/lapb_in.c:550
lapb_data_received+0x65/0xf0 net/lapb/lapb_iface.c:399
lapbeth_rcv+0x3a6/0x6e0 drivers/net/wan/lapbether.c:142
__netif_receive_skb_one_core+0x1b2/0x1e0 net/core/dev.c:6202
__netif_receive_skb+0x1f/0x120 net/core/dev.c:6315
process_backlog+0x37a/0x1580 net/core/dev.c:6666
__napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7733
napi_poll net/core/dev.c:7796 [inline]
net_rx_action+0xa40/0xf20 net/core/dev.c:7953
handle_softirqs+0x1ea/0xa00 kernel/softirq.c:622
do_softirq kernel/softirq.c:523 [inline]
do_softirq+0xac/0xe0 kernel/softirq.c:510
</IRQ>
<TASK>
__local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450
spin_unlock_bh include/linux/spinlock.h:396 [inline]
batadv_purge_outstanding_packets+0xc0/0x290 net/batman-adv/send.c:1110
batadv_hardif_disable_interface.cold+0x316/0x80b net/batman-adv/hard-interface.c:847
batadv_meshif_destroy_netlink+0x79/0x150 net/batman-adv/mesh-interface.c:1093
default_device_exit_batch+0x70c/0xc10 net/core/dev.c:13071
ops_exit_list net/core/net_namespace.c:205 [inline]
ops_undo_list+0x363/0xab0 net/core/net_namespace.c:252
cleanup_net+0x499/0x920 net/core/net_namespace.c:702
process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314
process_scheduled_works kernel/workqueue.c:3397 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
----------------
Code disassembly (best guess):
0: 0b 90 eb bf 48 85 or -0x7ab74015(%rax),%edx
6: ed in (%dx),%eax
7: 74 c6 je 0xffffffcf
9: 48 89 2d a0 de 17 16 mov %rbp,0x1617dea0(%rip) # 0x1617deb0
10: 48 89 ea mov %rbp,%rdx
13: 31 ed xor %ebp,%ebp
15: e9 0b ff ff ff jmp 0xffffff25
1a: 39 c1 cmp %eax,%ecx
1c: 72 1f jb 0x3d
1e: 48 85 d2 test %rdx,%rdx
21: 74 20 je 0x43
23: 48 8d 3d ae e6 b3 0b lea 0xbb3e6ae(%rip),%rdi # 0xbb3e6d8
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: 45 31 f6 xor %r14d,%r14d
32: 48 85 ed test %rbp,%rbp
35: 0f 85 37 fa ff ff jne 0xfffffa72
3b: eb 92 jmp 0xffffffcf
3d: 90 nop
3e: 0f 0b ud2


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