[syzbot] [net?] kernel BUG in qlist_free_all (4)

[syzbot <syzbot+b7a5f122d6dd573df0d1@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    df685633c3db Merge tag 'rcu-fixes.v7.1-20260519a' of git:/..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10897536580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d0f0911eedbc130a
dashboard link: https://syzkaller.appspot.com/bug?extid=b7a5f122d6dd573df0d1
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: https://storage.googleapis.com/syzbot-assets/90074e46cb62/disk-df685633.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/691247547753/vmlinux-df685633.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e1c705a2acac/bzImage-df685633.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b7a5f122d6dd573df0d1@syzkaller.appspotmail.com

------------[ cut here ]------------
kernel BUG at arch/x86/mm/physaddr.c:28!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 101 PID: 5289 Comm: dhcpcd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:__phys_addr+0x99/0x100 arch/x86/mm/physaddr.c:28
Code: 84 d2 75 28 0f b6 0d 57 a9 1e 0f 80 f9 3f 0f 87 a7 ed 67 ff 48 89 e8 48 d3 e8 48 85 c0 75 0a 48 89 e8 5b 5d c3 cc cc cc cc 90 <0f> 0b 48 c7 c7 e1 ed d7 90 e8 39 8f bb 00 eb ca 48 c7 c0 10 f0 5b
RSP: 0018:ffffc9000366f538 EFLAGS: 00010287
RAX: 840077090033186c RBX: 83ffff890033186c RCX: 000000080020001a
RDX: dffffc0000000000 RSI: 000000000020001a RDI: 83ffff888033186c
RBP: 840077088033186c R08: ffff88802d950001 R09: 000000080020001a
R10: 0000000000000001 R11: 0000000000000000 R12: 83ffff888033186c
R13: 0000000000000000 R14: ffffc9000366f580 R15: ffff8880b85439b0
FS:  00007f66bbcd2780(0000) GS:ffff888124474000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555588f66a38 CR3: 000000007ac58000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 virt_to_slab mm/slab.h:168 [inline]
 qlink_to_cache mm/kasan/quarantine.c:131 [inline]
 qlist_free_all+0x5f/0xf0 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4569 [inline]
 slab_alloc_node mm/slub.c:4898 [inline]
 kmem_cache_alloc_node_noprof+0x25a/0x6f0 mm/slub.c:4950
 __alloc_skb+0x140/0x710 net/core/skbuff.c:702
 alloc_skb include/linux/skbuff.h:1383 [inline]
 alloc_skb_with_frags+0xdd/0x760 net/core/skbuff.c:6734
 sock_alloc_send_pskb+0x801/0x980 net/core/sock.c:2998
 unix_dgram_sendmsg+0x3c7/0x1810 net/unix/af_unix.c:2141
 unix_seqpacket_sendmsg+0x12a/0x1d0 net/unix/af_unix.c:2542
 sock_sendmsg_nosec net/socket.c:787 [inline]
 __sock_sendmsg net/socket.c:802 [inline]
 sock_write_iter+0x524/0x5a0 net/socket.c:1254
 do_iter_readv_writev+0x6ee/0x920 fs/read_write.c:829
 vfs_writev+0x360/0xe10 fs/read_write.c:1059
 do_writev+0x28a/0x340 fs/read_write.c:1105
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f66bbd5c407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffd60c66880 EFLAGS: 00000202 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f66bbcd2780 RCX: 00007f66bbd5c407
RDX: 0000000000000005 RSI: 00007ffd60c668e0 RDI: 000000000000000a
RBP: 000056120f92f400 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000056120f92f400
R13: 000000000000012c R14: 00000000ffffffff R15: 0000000000000000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__phys_addr+0x99/0x100 arch/x86/mm/physaddr.c:28
Code: 84 d2 75 28 0f b6 0d 57 a9 1e 0f 80 f9 3f 0f 87 a7 ed 67 ff 48 89 e8 48 d3 e8 48 85 c0 75 0a 48 89 e8 5b 5d c3 cc cc cc cc 90 <0f> 0b 48 c7 c7 e1 ed d7 90 e8 39 8f bb 00 eb ca 48 c7 c0 10 f0 5b
RSP: 0018:ffffc9000366f538 EFLAGS: 00010287
RAX: 840077090033186c RBX: 83ffff890033186c RCX: 000000080020001a
RDX: dffffc0000000000 RSI: 000000000020001a RDI: 83ffff888033186c
RBP: 840077088033186c R08: ffff88802d950001 R09: 000000080020001a
R10: 0000000000000001 R11: 0000000000000000 R12: 83ffff888033186c
R13: 0000000000000000 R14: ffffc9000366f580 R15: ffff8880b85439b0
FS:  00007f66bbcd2780(0000) GS:ffff888124374000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdd954c9e80 CR3: 000000007ac58000 CR4: 00000000003526f0


---
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