[syzbot] WARNING in isotp_tx_timer_handler (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 46b348fd2d81 alx: acquire mutex for alx_reinit in alx_chan..
git tree: net
console output: https://syzkaller.appspot.com/x/log.txt?x=15da96e5700000
kernel config: https://syzkaller.appspot.com/x/.config?x=442f8ac61e60a75e
dashboard link: https://syzkaller.appspot.com/bug?extid=2339c27f5c66c652843e
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=165c76ad700000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=143da461700000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2339c2...@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 1 PID: 19 at net/can/isotp.c:852 isotp_tx_timer_handler+0x717/0xcd0 net/can/isotp.c:852
Modules linked in:
CPU: 1 PID: 19 Comm: ksoftirqd/1 Not tainted 5.17.0-rc7-syzkaller-00198-g46b348fd2d81 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:isotp_tx_timer_handler+0x717/0xcd0 net/can/isotp.c:852
Code: f9 44 0f b6 25 3b 23 56 05 31 ff 44 89 e6 e8 f0 56 4f f9 45 84 e4 0f 85 9d fa ff ff e9 4e 01 20 01 85 ed 75 52 e8 59 54 4f f9 <0f> 0b 45 31 e4 e8 4f 54 4f f9 48 8b 74 24 40 48 b8 00 00 00 00 00
RSP: 0018:ffffc90000d97c40 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88806f490568 RCX: 0000000000000100
RDX: ffff888011945700 RSI: ffffffff88296bd7 RDI: 0000000000000003
RBP: 0000000000000000 R08: ffffffff8ac3c440 R09: ffffffff8829656f
R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000000
R13: ffff8880b9d2a880 R14: ffff8880b9d2a600 R15: ffffffff882964c0
FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5c3133d1d8 CR3: 000000006b70d000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1749
hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1766
__do_softirq+0x29b/0x9c2 kernel/softirq.c:558
run_ksoftirqd kernel/softirq.c:921 [inline]
run_ksoftirqd+0x2d/0x60 kernel/softirq.c:913
smpboot_thread_fn+0x645/0x9c0 kernel/smpboot.c:164
kthread+0x2e9/0x3a0 kernel/kthread.c:377
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>


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[Oliver Hartkopp]

Hi all,

thanks for the report!

A patch to fix the issue has been posted for the "net-next" tree here:

https://lore.kernel.org/netdev/20220315203748....@hartkopp.net/T/#u

I sent it to the net-next tree as it fits best to get it into upstream
before the merge window opens IMO.

Linus' tree (and the stable kernels) need a different patch due to
current changes in net-next. A patch for the non net-next kernels is
available too.

The fix is not critical. So there's no hurry to get it into Linus' tree
and the stable trees.

Best regards,
Oliver