syzbot


kernel BUG in skbprio_enqueue

Status: upstream: reported C repro on 2025/03/27 10:01
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+a3422a19b05ea96bee18@syzkaller.appspotmail.com
Fix commit: ce8fe975fd99 net_sched: skbprio: Remove overly strict queue assertions
Patched on: [ci-qemu-gce-upstream-auto ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb], missing on: [ci-qemu-native-arm64-kvm ci-qemu2-arm32 ci-qemu2-riscv64]
First crash: 29d, last: 28d
Discussions (2)
Title Replies (including bot) Last reply
[Patch net 1/2] net_sched: skbprio: Remove overly strict queue assertions 1 (1) 2025/03/29 22:25
[syzbot] [net?] kernel BUG in skbprio_enqueue 1 (2) 2025/03/28 20:53

Sample crash report:
------------[ cut here ]------------
kernel BUG at net/sched/sch_skbprio.c:127!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 1037 Comm: kworker/u4:6 Not tainted 6.14.0-syzkaller-03565-gf6e0150b2003 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:skbprio_enqueue+0x1123/0x1150 net/sched/sch_skbprio.c:127
Code: 4c 89 fe e8 df 18 28 fb 4c 8b 6c 24 10 48 ba 00 00 00 00 00 fc ff df e9 87 f5 ff ff e8 76 2c b6 f7 90 0f 0b e8 6e 2c b6 f7 90 <0f> 0b 89 f9 80 e1 07 80 c1 03 38 c1 7c 88 e8 aa 58 1e f8 eb 81 89
RSP: 0000:ffffc9000252e780 EFLAGS: 00010293
RAX: ffffffff8a0d4a22 RBX: 0000000000000002 RCX: ffff8880003c8000
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000001
RBP: 0000000000000000 R08: ffffffff8a0d41e8 R09: 0000000000000000
R10: ffff8880436a9640 R11: ffffed10086d52ca R12: ffff8880361458c0
R13: ffff888036144000 R14: 0000000000000088 R15: ffff888036145dc0
FS:  0000000000000000(0000) GS:ffff88808c824000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f19a898ff38 CR3: 0000000000d22000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 qdisc_enqueue include/net/sch_generic.h:850 [inline]
 tbf_enqueue+0x362/0x6e0 net/sched/sch_tbf.c:258
 dev_qdisc_enqueue+0x4b/0x290 net/core/dev.c:4008
 __dev_xmit_skb net/core/dev.c:4104 [inline]
 __dev_queue_xmit+0xf13/0x3f60 net/core/dev.c:4618
 dev_queue_xmit include/linux/netdevice.h:3313 [inline]
 neigh_hh_output include/net/neighbour.h:523 [inline]
 neigh_output include/net/neighbour.h:537 [inline]
 ip_finish_output2+0xcd5/0x12e0 net/ipv4/ip_output.c:236
 iptunnel_xmit+0x560/0x9c0 net/ipv4/ip_tunnel_core.c:82
 udp_tunnel_xmit_skb+0x264/0x3c0 net/ipv4/udp_tunnel_core.c:173
 geneve_xmit_skb drivers/net/geneve.c:916 [inline]
 geneve_xmit+0x2119/0x2c30 drivers/net/geneve.c:1039
 __netdev_start_xmit include/linux/netdevice.h:5151 [inline]
 netdev_start_xmit include/linux/netdevice.h:5160 [inline]
 xmit_one net/core/dev.c:3800 [inline]
 dev_hard_start_xmit+0x27a/0x7d0 net/core/dev.c:3816
 __dev_queue_xmit+0x1b80/0x3f60 net/core/dev.c:4652
 dev_queue_xmit include/linux/netdevice.h:3313 [inline]
 neigh_hh_output include/net/neighbour.h:523 [inline]
 neigh_output include/net/neighbour.h:537 [inline]
 ip6_finish_output2+0x128c/0x17e0 net/ipv6/ip6_output.c:141
 __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline]
 ip6_finish_output+0x421/0x840 net/ipv6/ip6_output.c:226
 NF_HOOK+0xa0/0x440 include/linux/netfilter.h:314
 mld_sendpack+0x84a/0xdb0 net/ipv6/mcast.c:1868
 ipv6_mc_dad_complete+0x88/0x490 net/ipv6/mcast.c:2293
 addrconf_dad_completed+0x714/0xcd0 net/ipv6/addrconf.c:4336
 addrconf_dad_work+0xdbe/0x16a0 net/ipv6/addrconf.c:-1
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd30 kernel/workqueue.c:3400
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:skbprio_enqueue+0x1123/0x1150 net/sched/sch_skbprio.c:127
Code: 4c 89 fe e8 df 18 28 fb 4c 8b 6c 24 10 48 ba 00 00 00 00 00 fc ff df e9 87 f5 ff ff e8 76 2c b6 f7 90 0f 0b e8 6e 2c b6 f7 90 <0f> 0b 89 f9 80 e1 07 80 c1 03 38 c1 7c 88 e8 aa 58 1e f8 eb 81 89
RSP: 0000:ffffc9000252e780 EFLAGS: 00010293
RAX: ffffffff8a0d4a22 RBX: 0000000000000002 RCX: ffff8880003c8000
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000001
RBP: 0000000000000000 R08: ffffffff8a0d41e8 R09: 0000000000000000
R10: ffff8880436a9640 R11: ffffed10086d52ca R12: ffff8880361458c0
R13: ffff888036144000 R14: 0000000000000088 R15: ffff888036145dc0
FS:  0000000000000000(0000) GS:ffff88808c824000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f19a898ff38 CR3: 0000000000d22000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/03/27 11:41 upstream f6e0150b2003 20510e88 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root kernel BUG in skbprio_enqueue
2025/03/27 10:23 upstream f6e0150b2003 20510e88 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root kernel BUG in skbprio_enqueue
2025/03/27 09:25 upstream f6e0150b2003 20510e88 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root kernel BUG in skbprio_enqueue
2025/03/27 08:17 upstream f6e0150b2003 20510e88 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci-snapshot-upstream-root kernel BUG in skbprio_enqueue
2025/03/27 06:49 upstream f6e0150b2003 20510e88 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root kernel BUG in skbprio_enqueue
2025/03/27 05:52 upstream f6e0150b2003 20510e88 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root kernel BUG in skbprio_enqueue
2025/03/27 04:20 upstream f6e0150b2003 20510e88 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root kernel BUG in skbprio_enqueue
* Struck through repros no longer work on HEAD.