Re: [syzbot] [net?] [afs?] kernel BUG in rxrpc_destroy_all_connections (2)

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
kernel BUG in rxrpc_destroy_all_connections

rxrpc: AF_RXRPC: proc conn 7f4 cid fba44d28 state 7 ref 1 act 0 flags 2 cache_empty 1 calls 0000000000000000 0000000000000000 0000000000000000 0000000000000000 bundle ffff88802d3d1000
rxrpc: Assertion failed
------------[ cut here ]------------
kernel BUG at net/rxrpc/conn_object.c:506!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 3 UID: 0 PID: 5762 Comm: kworker/u32:2 Not tainted syzkaller #0 PREEMPT(full) 
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:rxrpc_destroy_all_connections.cold+0x12/0x34f net/rxrpc/conn_object.c:506
Code: ff 90 0f 0b e8 6e a7 99 00 48 c7 c7 20 73 5d 8d e8 72 be af ff 90 0f 0b e8 5a a7 99 00 48 c7 c7 20 73 5d 8d e8 5e be af ff 90 <0f> 0b e8 46 a7 99 00 48 c7 c7 60 78 5d 8d e8 4a be af ff 4c 89 e7
RSP: 0018:ffffc9000443f928 EFLAGS: 00010286
RAX: 0000000000000017 RBX: ffff888054ab4000 RCX: 0000000000000000
RDX: 0000000000000017 RSI: ffffffff81ea2579 RDI: fffff52000887f16
RBP: ffff888054ab4064 R08: 0000000000000007 R09: 0000000000000000
R10: 8000000000000000 R11: 0000000000000001 R12: ffff888054ab4098
R13: ffff888054ab3e70 R14: ffff888054ab4078 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880d5e52000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe0fcd74e9c CR3: 0000000035950000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 rxrpc_exit_net+0x7b/0xc0 net/rxrpc/net_ns.c:113
 ops_exit_list net/core/net_namespace.c:200 [inline]
 ops_undo_list+0x2ee/0xab0 net/core/net_namespace.c:253
 cleanup_net+0x499/0x920 net/core/net_namespace.c:706
 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:rxrpc_destroy_all_connections.cold+0x12/0x34f net/rxrpc/conn_object.c:506
Code: ff 90 0f 0b e8 6e a7 99 00 48 c7 c7 20 73 5d 8d e8 72 be af ff 90 0f 0b e8 5a a7 99 00 48 c7 c7 20 73 5d 8d e8 5e be af ff 90 <0f> 0b e8 46 a7 99 00 48 c7 c7 60 78 5d 8d e8 4a be af ff 4c 89 e7
RSP: 0018:ffffc9000443f928 EFLAGS: 00010286
RAX: 0000000000000017 RBX: ffff888054ab4000 RCX: 0000000000000000
RDX: 0000000000000017 RSI: ffffffff81ea2579 RDI: fffff52000887f16
RBP: ffff888054ab4064 R08: 0000000000000007 R09: 0000000000000000
R10: 8000000000000000 R11: 0000000000000001 R12: ffff888054ab4098
R13: ffff888054ab3e70 R14: ffff888054ab4078 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880d5e52000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe0fcd74e9c CR3: 0000000035950000 CR4: 0000000000352ef0


Tested on:

commit:         a7bfaba4 ipv6: fix prefix route expiry in modify_prefi..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git
console output: https://syzkaller.appspot.com/x/log.txt?x=13e06605580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=7d012d9c67977ee4
dashboard link: https://syzkaller.appspot.com/bug?extid=89001660f14fb7684c83
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
patch:          https://syzkaller.appspot.com/x/patch.diff?x=124d5315580000