UBSAN: undefined-behaviour in __qdisc_calculate_pkt_len

Status: upstream: reported C repro on 2020/09/21 00:09
Reported-by: syzbot+45cd53c935be1e17da97@syzkaller.appspotmail.com
First crash: 2162d, last: 2131d
Fix bisection: failed (error log, bisect log)
  

Sample crash report:
================================================================================
UBSAN: Undefined behaviour in net/sched/sch_api.c:561:7
shift exponent 129 is too large for 32-bit type 'int'
CPU: 1 PID: 3741 Comm: kworker/1:3 Not tainted 4.19.149-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x22c/0x33e lib/dump_stack.c:118
 ubsan_epilogue+0xe/0x3a lib/ubsan.c:161
 __ubsan_handle_shift_out_of_bounds.cold+0x1c4/0x250 lib/ubsan.c:422
 __qdisc_calculate_pkt_len+0x3bb/0x570 net/sched/sch_api.c:561
 qdisc_calculate_pkt_len include/net/sch_generic.h:697 [inline]
 __dev_xmit_skb net/core/dev.c:3443 [inline]
 __dev_queue_xmit+0x1372/0x2ec0 net/core/dev.c:3807
 neigh_hh_output include/net/neighbour.h:491 [inline]
 neigh_output include/net/neighbour.h:499 [inline]
 ip_finish_output2+0xc04/0x1640 net/ipv4/ip_output.c:230
 ip_finish_output+0x88e/0xd80 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:278 [inline]
 ip_output+0x203/0x650 net/ipv4/ip_output.c:406
 dst_output include/net/dst.h:455 [inline]
 ip_local_out+0xaf/0x170 net/ipv4/ip_output.c:125
 iptunnel_xmit+0x63e/0xa30 net/ipv4/ip_tunnel_core.c:91
 geneve_xmit_skb drivers/net/geneve.c:865 [inline]
 geneve_xmit+0xf46/0x2ac0 drivers/net/geneve.c:938
 __netdev_start_xmit include/linux/netdevice.h:4333 [inline]
 netdev_start_xmit include/linux/netdevice.h:4347 [inline]
 xmit_one net/core/dev.c:3256 [inline]
 dev_hard_start_xmit+0x1a8/0x960 net/core/dev.c:3272
 __dev_queue_xmit+0x276a/0x2ec0 net/core/dev.c:3838
 neigh_resolve_output+0x55a/0x950 net/core/neighbour.c:1374
 neigh_output include/net/neighbour.h:501 [inline]
 ip6_finish_output2+0x1184/0x2370 net/ipv6/ip6_output.c:120
 ip6_finish_output+0x610/0xcc0 net/ipv6/ip6_output.c:154
 NF_HOOK_COND include/linux/netfilter.h:278 [inline]
 ip6_output+0x205/0x7c0 net/ipv6/ip6_output.c:171
 dst_output include/net/dst.h:455 [inline]
 NF_HOOK include/linux/netfilter.h:289 [inline]
 ndisc_send_skb+0xa6b/0x1860 net/ipv6/ndisc.c:491
 ndisc_send_ns+0x51d/0x840 net/ipv6/ndisc.c:633
 addrconf_dad_work+0xb78/0x1130 net/ipv6/addrconf.c:4075
 process_one_work+0x796/0x14e0 kernel/workqueue.c:2155
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2298
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
================================================================================

Crashes (85):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/10/05 19:12 linux-4.19.y b09c34517e1a 1880b4a9 .config console log report syz C ci2-linux-4-19
2020/09/21 00:23 linux-4.19.y 015e94d0e37b 9564d2e9 .config console log report syz C ci2-linux-4-19
2020/10/21 21:46 linux-4.19.y ad326970d25c 99c64d5c .config console log report info ci2-linux-4-19
2020/10/21 17:52 linux-4.19.y ad326970d25c 99c64d5c .config console log report info ci2-linux-4-19
2020/10/21 12:47 linux-4.19.y ad326970d25c 99c64d5c .config console log report info ci2-linux-4-19
2020/10/21 11:17 linux-4.19.y ad326970d25c 99c64d5c .config console log report info ci2-linux-4-19
2020/10/21 09:53 linux-4.19.y ad326970d25c e761439e .config console log report info ci2-linux-4-19
2020/10/20 03:45 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/19 12:14 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/19 09:33 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/18 07:40 linux-4.19.y ad326970d25c fea47c01 .config console log report info ci2-linux-4-19
2020/10/18 00:27 linux-4.19.y ad326970d25c fea47c01 .config console log report info ci2-linux-4-19
2020/10/17 12:16 linux-4.19.y ad326970d25c fea47c01 .config console log report info ci2-linux-4-19
2020/10/17 09:11 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/15 21:55 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/15 08:57 linux-4.19.y a1b977b49b66 63869021 .config console log report info ci2-linux-4-19
2020/10/14 23:30 linux-4.19.y a1b977b49b66 fc7735a2 .config console log report info ci2-linux-4-19
2020/10/14 22:26 linux-4.19.y a1b977b49b66 fc7735a2 .config console log report info ci2-linux-4-19
2020/10/13 21:46 linux-4.19.y a1b977b49b66 fc7735a2 .config console log report info ci2-linux-4-19
2020/10/13 20:05 linux-4.19.y a1b977b49b66 fc7735a2 .config console log report info ci2-linux-4-19
2020/10/13 13:14 linux-4.19.y a1b977b49b66 bd69ee0d .config console log report info ci2-linux-4-19
2020/10/13 08:54 linux-4.19.y a1b977b49b66 bd69ee0d .config console log report info ci2-linux-4-19
2020/10/13 05:42 linux-4.19.y a1b977b49b66 d32b0bbf .config console log report info ci2-linux-4-19
2020/10/12 16:53 linux-4.19.y a1b977b49b66 d32b0bbf .config console log report info ci2-linux-4-19
2020/10/10 22:46 linux-4.19.y a1b977b49b66 4a77ae0b .config console log report info ci2-linux-4-19
2020/10/10 12:49 linux-4.19.y a1b977b49b66 b74c49a6 .config console log report info ci2-linux-4-19
2020/10/10 10:26 linux-4.19.y a1b977b49b66 b74c49a6 .config console log report info ci2-linux-4-19
2020/10/10 09:03 linux-4.19.y a1b977b49b66 b74c49a6 .config console log report info ci2-linux-4-19
2020/10/10 01:33 linux-4.19.y a1b977b49b66 93817d89 .config console log report info ci2-linux-4-19
2020/10/09 21:49 linux-4.19.y a1b977b49b66 93817d89 .config console log report info ci2-linux-4-19
2020/10/09 20:28 linux-4.19.y a1b977b49b66 fa79ed2a .config console log report info ci2-linux-4-19
2020/10/09 10:13 linux-4.19.y a1b977b49b66 fa79ed2a .config console log report info ci2-linux-4-19
2020/10/09 08:46 linux-4.19.y a1b977b49b66 fa79ed2a .config console log report info ci2-linux-4-19
2020/10/08 17:03 linux-4.19.y a1b977b49b66 92390980 .config console log report info ci2-linux-4-19
2020/10/08 15:17 linux-4.19.y a1b977b49b66 92390980 .config console log report info ci2-linux-4-19
2020/10/08 11:44 linux-4.19.y a1b977b49b66 92390980 .config console log report info ci2-linux-4-19
2020/10/08 09:52 linux-4.19.y a1b977b49b66 1880b4a9 .config console log report info ci2-linux-4-19
2020/10/07 08:34 linux-4.19.y a1b977b49b66 1880b4a9 .config console log report info ci2-linux-4-19
2020/10/06 12:57 linux-4.19.y b09c34517e1a 1880b4a9 .config console log report info ci2-linux-4-19
2020/10/06 01:54 linux-4.19.y b09c34517e1a 1880b4a9 .config console log report info ci2-linux-4-19
2020/10/05 14:52 linux-4.19.y b09c34517e1a 1880b4a9 .config console log report info ci2-linux-4-19
2020/10/04 10:13 linux-4.19.y b09c34517e1a 5ef9c291 .config console log report info ci2-linux-4-19
2020/10/04 09:57 linux-4.19.y b09c34517e1a 5ef9c291 .config console log report info ci2-linux-4-19
2020/10/04 09:14 linux-4.19.y b09c34517e1a 5ef9c291 .config console log report info ci2-linux-4-19
2020/10/04 01:21 linux-4.19.y b09c34517e1a 1a3f9408 .config console log report info ci2-linux-4-19
2020/10/03 16:48 linux-4.19.y b09c34517e1a 1a3f9408 .config console log report info ci2-linux-4-19
2020/09/29 01:10 linux-4.19.y 10ad6cfd5736 1b88c6d5 .config console log report info ci2-linux-4-19
2020/09/29 00:40 linux-4.19.y 10ad6cfd5736 1b88c6d5 .config console log report info ci2-linux-4-19
2020/09/29 00:08 linux-4.19.y 10ad6cfd5736 1b88c6d5 .config console log report info ci2-linux-4-19
2020/09/28 20:32 linux-4.19.y 10ad6cfd5736 6bfdbe89 .config console log report info ci2-linux-4-19
2020/09/28 07:24 linux-4.19.y 10ad6cfd5736 5dd8aee8 .config console log report info ci2-linux-4-19
2020/09/27 05:11 linux-4.19.y 10ad6cfd5736 5dd8aee8 .config console log report info ci2-linux-4-19
2020/09/26 10:12 linux-4.19.y d09b80172c22 4a006f63 .config console log report info ci2-linux-4-19
2020/09/26 08:12 linux-4.19.y d09b80172c22 4a006f63 .config console log report info ci2-linux-4-19
2020/09/26 01:44 linux-4.19.y d09b80172c22 4a006f63 .config console log report info ci2-linux-4-19
2020/09/25 18:02 linux-4.19.y d09b80172c22 4a006f63 .config console log report info ci2-linux-4-19
2020/09/25 16:35 linux-4.19.y d09b80172c22 4a006f63 .config console log report info ci2-linux-4-19
2020/09/22 05:37 linux-4.19.y 015e94d0e37b 9e1fa68e .config console log report info ci2-linux-4-19
2020/09/21 00:08 linux-4.19.y 015e94d0e37b 9564d2e9 .config console log report info ci2-linux-4-19
* Struck through repros no longer work on HEAD.