bisecting fixing commit since f116b96685a046a89c25d4a6ba2da489145c8888
building syzkaller on d01bb02a96019cda0fa8c46e5c6d5eb66a273f17
testing commit f116b96685a046a89c25d4a6ba2da489145c8888 with gcc (GCC) 8.1.0
kernel signature: e26bfe040ce6b414b3a8fdd8a6a73d54cf4f13677973e55a02e4c1f3af639ada
all runs: crashed: divide error in tabledist
testing current HEAD fb33c6510d5595144d585aa194d377cf74d31911
testing commit fb33c6510d5595144d585aa194d377cf74d31911 with gcc (GCC) 8.1.0
kernel signature: 9438a8c52902d5db0beb73695733041bce8ec0f9be1daa5fc2bf6ce258a5b49a
all runs: crashed: divide error in tabledist
revisions tested: 2, total time: 19m18.194512882s (build: 11m56.819352203s, test: 6m37.754972451s)
the crash still happens on HEAD
commit msg: Linux 5.6-rc6
crash: divide error in tabledist
divide error: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 2789 Comm: kworker/1:36 Not tainted 5.6.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:tabledist.part.20+0x10b/0x150 net/sched/sch_netem.c:333
Code: 3c 18 49 8d 80 ff 1f 00 00 49 0f 49 c0 48 83 c4 08 5b 48 c1 f8 0d 41 5c 48 01 f8 41 5d 5d c3 43 8d 4c 2d 00 31 d2 48 83 c4 08 <f7> f1 49 63 c5 48 29 c3 48 8d 04 1a 5b 41 5c 41 5d 5d c3 4c 89 e7
RSP: 0018:ffff8880a04bf498 EFLAGS: 00010282
RAX: 0000000006998b85 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000080000000 RDI: ffffffff8a23a7a0
RBP: ffff8880a04bf4b0 R08: 0000000000000001 R09: ffff88808d6751c0
R10: ffffed1011bbbc78 R11: ffff88808ddde3c7 R12: 0000000000000000
R13: 0000000080000000 R14: ffff8880a4446000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880aed00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff502ab010 CR3: 000000007f9ce000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 tabledist net/sched/sch_netem.c:536 [inline]
 netem_enqueue+0xdae/0x2f40 net/sched/sch_netem.c:536
 __dev_xmit_skb net/core/dev.c:3710 [inline]
 __dev_queue_xmit+0x105c/0x2960 net/core/dev.c:4021
 dev_queue_xmit+0xb/0x10 net/core/dev.c:4085
 neigh_hh_output include/net/neighbour.h:499 [inline]
 neigh_output include/net/neighbour.h:508 [inline]
 ip6_finish_output2+0xc90/0x2340 net/ipv6/ip6_output.c:116
 __ip6_finish_output+0x36c/0x930 net/ipv6/ip6_output.c:142
 ip6_finish_output+0x27/0x170 net/ipv6/ip6_output.c:152
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip6_output+0x1e4/0x750 net/ipv6/ip6_output.c:175
 dst_output include/net/dst.h:436 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 mld_sendpack+0x86b/0xca0 net/ipv6/mcast.c:1682
 mld_send_initial_cr.part.32+0xd7/0x110 net/ipv6/mcast.c:2099
 mld_send_initial_cr net/ipv6/mcast.c:2112 [inline]
 ipv6_mc_dad_complete+0x14d/0x1a0 net/ipv6/mcast.c:2106
 addrconf_dad_completed+0x86f/0xbb0 net/ipv6/addrconf.c:4182
 addrconf_dad_work+0x668/0xff0 net/ipv6/addrconf.c:4113
 process_one_work+0x88b/0x1680 kernel/workqueue.c:2266
 worker_thread+0x85/0xb60 kernel/workqueue.c:2412
 kthread+0x331/0x3f0 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Modules linked in:
---[ end trace 76641b3e8891427c ]---
RIP: 0010:tabledist.part.20+0x10b/0x150 net/sched/sch_netem.c:333
Code: 3c 18 49 8d 80 ff 1f 00 00 49 0f 49 c0 48 83 c4 08 5b 48 c1 f8 0d 41 5c 48 01 f8 41 5d 5d c3 43 8d 4c 2d 00 31 d2 48 83 c4 08 <f7> f1 49 63 c5 48 29 c3 48 8d 04 1a 5b 41 5c 41 5d 5d c3 4c 89 e7
RSP: 0018:ffff8880a04bf498 EFLAGS: 00010282
RAX: 0000000006998b85 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000080000000 RDI: ffffffff8a23a7a0
RBP: ffff8880a04bf4b0 R08: 0000000000000001 R09: ffff88808d6751c0
R10: ffffed1011bbbc78 R11: ffff88808ddde3c7 R12: 0000000000000000
R13: 0000000080000000 R14: ffff8880a4446000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880aed00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff502ab010 CR3: 000000000866d000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400