[syzbot] [net?] kernel BUG in net_dm_packet_work (2)

[syzbot] [net?] kernel BUG in net_dm_packet_work (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    08df884136f1 Merge tag 'thermal-7.3-rc3' of git://git.kern..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14cd4925580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8c5c3949d762a91f
dashboard link: https://syzkaller.appspot.com/bug?extid=586af68eb819833c2d91
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-08df8841.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/21cf9eeaddab/vmlinux-08df8841.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a041f1e01a69/bzImage-08df8841.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+586af68eb819833c2d91@syzkaller.appspotmail.com

skb frag:     00000100: 44 d2 0a a2 e2 47 a7 df 6f 97 84 d1 f7 fb c3 2a
skb frag:     00000110: 21 54 9f 61 2b aa b4 19 63 72 89 80 f0 62 f3 61
skb frag:     00000120: 9f 89 a0 49 03 f5 e7 66 b6 4b 34 44 cd b9 03 b5
------------[ cut here ]------------
kernel BUG at ./include/linux/skbuff.h:2847!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 1 UID: 0 PID: 5877 Comm: kworker/1:7 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: events net_dm_packet_work
RIP: 0010:__skb_pull include/linux/skbuff.h:2847 [inline]
RIP: 0010:skb_pull_inline include/linux/skbuff.h:2854 [inline]
RIP: 0010:skb_pull.cold+0x29/0x2b net/core/skbuff.c:2677
Code: 0b e8 6b b3 9c 00 44 89 65 70 89 de 48 c7 c7 60 cc 38 8d e8 b9 e6 b2 ff 31 d2 48 89 ee 48 c7 c7 a0 cc 38 8d e8 e8 30 26 08 90 <0f> 0b e8 40 b3 9c 00 4c 89 e2 be 01 00 00 00 48 c7 c7 00 ff ca 90
RSP: 0018:ffffc900044df9f0 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 00000000000000ea RCX: 0000000000000000
RDX: ffff88802461a580 RSI: ffffffff816f5ede RDI: ffff88802461a580
RBP: ffff88802c76ca00 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000001b38
R13: 0000000000001a4e R14: 0000000000001b38 R15: ffff88802c76ca00
FS:  0000000000000000(0000) GS:ffff8880d5c5c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa64e227dac CR3: 00000000647d3000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 net_dm_packet_report net/core/drop_monitor.c:700 [inline]
 net_dm_packet_work+0xafd/0x1290 net/core/drop_monitor.c:739
 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396
 process_scheduled_works kernel/workqueue.c:3479 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__skb_pull include/linux/skbuff.h:2847 [inline]
RIP: 0010:skb_pull_inline include/linux/skbuff.h:2854 [inline]
RIP: 0010:skb_pull.cold+0x29/0x2b net/core/skbuff.c:2677
Code: 0b e8 6b b3 9c 00 44 89 65 70 89 de 48 c7 c7 60 cc 38 8d e8 b9 e6 b2 ff 31 d2 48 89 ee 48 c7 c7 a0 cc 38 8d e8 e8 30 26 08 90 <0f> 0b e8 40 b3 9c 00 4c 89 e2 be 01 00 00 00 48 c7 c7 00 ff ca 90
RSP: 0018:ffffc900044df9f0 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 00000000000000ea RCX: 0000000000000000
RDX: ffff88802461a580 RSI: ffffffff816f5ede RDI: ffff88802461a580
RBP: ffff88802c76ca00 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000001b38
R13: 0000000000001a4e R14: 0000000000001b38 R15: ffff88802c76ca00
FS:  0000000000000000(0000) GS:ffff8880d5c5c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa64e227dac CR3: 000000000eb96000 CR4: 0000000000352ef0


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup