linux-kernel - [syzbot] [net?] WARNING in taprio_get_start

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Message-ID: <684c5575.a00a0220.279073.0013.GAE@google.com>
Date: Fri, 13 Jun 2025 09:44:37 -0700
From: syzbot <syzbot+398e1ee4ca2cac05fddb@...kaller.appspotmail.com>
To: davem@...emloft.net, edumazet@...gle.com, horms@...nel.org, 
	jhs@...atatu.com, jiri@...nulli.us, kuba@...nel.org, 
	linux-kernel@...r.kernel.org, netdev@...r.kernel.org, pabeni@...hat.com, 
	syzkaller-bugs@...glegroups.com, vinicius.gomes@...el.com, 
	xiyou.wangcong@...il.com
Subject: [syzbot] [net?] WARNING in taprio_get_start_time (2)

Hello,

syzbot found the following issue on:

HEAD commit:    b549faa950e6 Merge branch 'net-bcmasp-add-support-for-gro'
git tree:       net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1003d10c580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c07f08ee4bcfb276
dashboard link: https://syzkaller.appspot.com/bug?extid=398e1ee4ca2cac05fddb
compiler:       Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6f82898e05e9/disk-b549faa9.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/df2850948ac5/vmlinux-b549faa9.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2d4c1db8f02d/bzImage-b549faa9.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+398e1ee4ca2cac05fddb@...kaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 1 PID: 11372 at net/sched/sch_taprio.c:1223 taprio_get_start_time+0x15e/0x190 net/sched/sch_taprio.c:1223
Modules linked in:
CPU: 1 UID: 0 PID: 11372 Comm: syz.0.1394 Not tainted 6.16.0-rc1-syzkaller-00189-gb549faa950e6 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:taprio_get_start_time+0x15e/0x190 net/sched/sch_taprio.c:1223
Code: 42 80 3c 28 00 74 08 48 89 df e8 5d bd 9d f8 4c 89 23 31 c0 5b 41 5c 41 5d 41 5e 41 5f 5d e9 99 ef e2 01 cc e8 e3 44 3a f8 90 <0f> 0b 90 b8 f2 ff ff ff eb e0 44 89 e9 80 e1 07 80 c1 03 38 c1 0f
RSP: 0018:ffffc9000478eee8 EFLAGS: 00010287
RAX: ffffffff89861a0d RBX: ffffc9000478efd8 RCX: 0000000000080000
RDX: ffffc9000f4da000 RSI: 0000000000000c35 RDI: 0000000000000c36
RBP: 0000000000000000 R08: ffffffff8fa10ef7 R09: 1ffffffff1f421de
R10: dffffc0000000000 R11: ffffffff81679c10 R12: 184898a57a6335ad
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f0656dd56c0(0000) GS:ffff888125d52000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000010000 CR3: 000000006029c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 taprio_change+0x2da5/0x3f60 net/sched/sch_taprio.c:1938
 taprio_init+0x959/0xbd0 net/sched/sch_taprio.c:2112
 qdisc_create+0x7ac/0xea0 net/sched/sch_api.c:1333
 __tc_modify_qdisc net/sched/sch_api.c:1758 [inline]
 tc_modify_qdisc+0x1426/0x2010 net/sched/sch_api.c:1822
 rtnetlink_rcv_msg+0x779/0xb70 net/core/rtnetlink.c:6953
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2534
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x75b/0x8d0 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:727
 ____sys_sendmsg+0x505/0x830 net/socket.c:2566
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620
 __sys_sendmsg net/socket.c:2652 [inline]
 __do_sys_sendmsg net/socket.c:2657 [inline]
 __se_sys_sendmsg net/socket.c:2655 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2655
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0658f8e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0656dd5038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f06591b6160 RCX: 00007f0658f8e929
RDX: 0000000000000000 RSI: 00002000000007c0 RDI: 000000000000000e
RBP: 00007f0659010b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f06591b6160 R15: 00007ffc8579ea48
 </TASK>


---
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