[syzbot] [afs?] [net?] KCSAN: data-race in rxrpc_peer_keepalive_worker / rxrpc_send_data_packet

[syzbot <syzbot+6182afad5045e6703b3d@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    30f09200cc4a Merge tag 'arm64-fixes' of git://git.kernel.o..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13446e12580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=655255e3ef31c19b
dashboard link: https://syzkaller.appspot.com/bug?extid=6182afad5045e6703b3d
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/445be400b5e4/disk-30f09200.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8be295d83690/vmlinux-30f09200.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ae2ac2a81686/bzImage-30f09200.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6182afad5045e6703b3d@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in rxrpc_peer_keepalive_worker / rxrpc_send_data_packet

write to 0xffff8881044ab560 of 8 bytes by task 4063 on cpu 1:
 rxrpc_send_data_packet+0x1593/0x1df0 net/rxrpc/output.c:714
 rxrpc_transmit_fresh_data net/rxrpc/call_event.c:255 [inline]
 rxrpc_transmit_some_data+0x63c/0x8b0 net/rxrpc/call_event.c:277
 rxrpc_input_call_event+0x8bb/0xf30 net/rxrpc/call_event.c:401
 rxrpc_io_thread+0x1c1e/0x21c0 net/rxrpc/io_thread.c:550
 kthread+0x489/0x510 kernel/kthread.c:463
 ret_from_fork+0x122/0x1b0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff8881044ab560 of 8 bytes by task 3500 on cpu 0:
 rxrpc_peer_keepalive_dispatch net/rxrpc/peer_event.c:268 [inline]
 rxrpc_peer_keepalive_worker+0x44e/0x800 net/rxrpc/peer_event.c:341
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3346
 worker_thread+0x582/0x770 kernel/workqueue.c:3427
 kthread+0x489/0x510 kernel/kthread.c:463
 ret_from_fork+0x122/0x1b0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x0000000000000000 -> 0x0000000000000029

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3500 Comm: kworker/u9:1 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: krxrpcd rxrpc_peer_keepalive_worker
==================================================================


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