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Date:   Mon, 24 Apr 2023 01:17:39 -0700
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Subject: [syzbot] [afs?] [net?] KCSAN: data-race in rxrpc_send_data / rxrpc_set_call_completion
From:   syzbot <syzbot+ebc945fdb4acd72cba78@syzkaller.appspotmail.com>
To:     davem@davemloft.net, dhowells@redhat.com, edumazet@google.com,
        kuba@kernel.org, linux-afs@lists.infradead.org,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        marc.dionne@auristor.com, netdev@vger.kernel.org,
        pabeni@redhat.com, syzkaller-bugs@googlegroups.com
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Hello,

syzbot found the following issue on:

HEAD commit:    148341f0a2f5 Merge tag 'vfs.misc.fixes.v6.3-rc6' of git://..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14a62269c80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=54d63ee086ae78d0
dashboard link: https://syzkaller.appspot.com/bug?extid=ebc945fdb4acd72cba78
compiler:       Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/1c557f92a6e1/disk-148341f0.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f2c85210e1ce/vmlinux-148341f0.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b019d0447709/bzImage-148341f0.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ebc945fdb4acd72cba78@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in rxrpc_send_data / rxrpc_set_call_completion

write to 0xffff888159cf3c50 of 4 bytes by task 25673 on cpu 1:
 rxrpc_set_call_completion+0x71/0x1c0 net/rxrpc/call_state.c:22
 rxrpc_send_data_packet+0xba9/0x1650 net/rxrpc/output.c:479
 rxrpc_transmit_one+0x1e/0x130 net/rxrpc/output.c:714
 rxrpc_decant_prepared_tx net/rxrpc/call_event.c:326 [inline]
 rxrpc_transmit_some_data+0x496/0x600 net/rxrpc/call_event.c:350
 rxrpc_input_call_event+0x564/0x1220 net/rxrpc/call_event.c:464
 rxrpc_io_thread+0x307/0x1d80 net/rxrpc/io_thread.c:461
 kthread+0x1ac/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

read to 0xffff888159cf3c50 of 4 bytes by task 25672 on cpu 0:
 rxrpc_send_data+0x29e/0x1950 net/rxrpc/sendmsg.c:296
 rxrpc_do_sendmsg+0xb7a/0xc20 net/rxrpc/sendmsg.c:726
 rxrpc_sendmsg+0x413/0x520 net/rxrpc/af_rxrpc.c:565
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg net/socket.c:747 [inline]
 ____sys_sendmsg+0x375/0x4c0 net/socket.c:2501
 ___sys_sendmsg net/socket.c:2555 [inline]
 __sys_sendmmsg+0x263/0x500 net/socket.c:2641
 __do_sys_sendmmsg net/socket.c:2670 [inline]
 __se_sys_sendmmsg net/socket.c:2667 [inline]
 __x64_sys_sendmmsg+0x57/0x60 net/socket.c:2667
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x00000000 -> 0xffffffea

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 25672 Comm: syz-executor.5 Not tainted 6.3.0-rc5-syzkaller-00005-g148341f0a2f5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
==================================================================


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