bisecting fixing commit since 3207316b3beec7e38e5dbe2f463df0cec71e0b97
building syzkaller on 79264ae39c1ef4b4875ab67d6f0c8c3e75aa6a34
testing commit 3207316b3beec7e38e5dbe2f463df0cec71e0b97 with gcc (GCC) 8.4.1 20210217
kernel signature: 8215529a75b114d4931ebe3991dd78ff4bb174981c53bf010671303e326898ee
all runs: crashed: divide error in netem_enqueue
testing current HEAD 3c8c23092588a23bf1856a64f58c37f477a413be
testing commit 3c8c23092588a23bf1856a64f58c37f477a413be with gcc (GCC) 8.4.1 20210217
kernel signature: db5400ae18061e344e85621a0aa2d0a06661d02f625f804e8c8152d45c829081
all runs: crashed: divide error in netem_enqueue
revisions tested: 2, total time: 27m45.844723586s (build: 20m24.624991161s, test: 6m49.76227217s)
the crash still happens on HEAD
commit msg: Linux 4.19.190
crash: divide error in netem_enqueue
IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready
IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
divide error: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 9892 Comm: syz-executor.5 Not tainted 4.19.190-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:netem_enqueue+0x10b8/0x2fa0 net/sched/sch_netem.c:516
Code: 8b 85 48 ff ff ff 8b 95 50 ff ff ff 48 8b 8d 58 ff ff ff 8b 85 60 ff ff ff 48 8b bd 70 ff ff ff 89 d6 31 d2 2b b7 84 00 00 00 <f7> f6 48 b8 00 00 00 00 00 fc ff df 48 01 d3 48 89 de 48 c1 ee 03
RSP: 0018:ffff888098cf7558 EFLAGS: 00010246
RAX: 00000000a1c55f2b RBX: ffff8880b500ba80 RCX: ffff88809ac25e18
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88809ac25d40
RBP: ffff888098cf7650 R08: 0000000000000001 R09: ffffed1017444552
R10: 0000000000000000 R11: ffff8880ba222a93 R12: ffff888098b95060
R13: 0000000000000004 R14: ffff888098b94d80 R15: 0000000000000000
FS:  00007fe243fe1700(0000) GS:ffff8880ba200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe738f4f9c CR3: 0000000090405000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __dev_xmit_skb net/core/dev.c:3494 [inline]
 __dev_queue_xmit+0x1098/0x2900 net/core/dev.c:3807
 dev_queue_xmit+0xb/0x10 net/core/dev.c:3871
 __netlink_deliver_tap_skb net/netlink/af_netlink.c:303 [inline]
 __netlink_deliver_tap net/netlink/af_netlink.c:321 [inline]
 netlink_deliver_tap+0x77e/0xb00 net/netlink/af_netlink.c:334
 netlink_deliver_tap_kernel net/netlink/af_netlink.c:343 [inline]
 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
 netlink_unicast+0x412/0x660 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x667/0xc60 net/netlink/af_netlink.c:1909
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg+0xac/0xf0 net/socket.c:632
 ___sys_sendmsg+0x647/0x950 net/socket.c:2115
 __sys_sendmsg+0xd9/0x180 net/socket.c:2153
 __do_sys_sendmsg net/socket.c:2162 [inline]
 __se_sys_sendmsg net/socket.c:2160 [inline]
 __x64_sys_sendmsg+0x73/0xb0 net/socket.c:2160
 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x465b09
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe243fe1188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 0000000000465b09
RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000004
RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008
R13: 00007ffcbf4ad8bf R14: 00007fe243fe1300 R15: 0000000000022000
Modules linked in:
---[ end trace 8147e4da43f1a528 ]---
RIP: 0010:netem_enqueue+0x10b8/0x2fa0 net/sched/sch_netem.c:516
Code: 8b 85 48 ff ff ff 8b 95 50 ff ff ff 48 8b 8d 58 ff ff ff 8b 85 60 ff ff ff 48 8b bd 70 ff ff ff 89 d6 31 d2 2b b7 84 00 00 00 <f7> f6 48 b8 00 00 00 00 00 fc ff df 48 01 d3 48 89 de 48 c1 ee 03
RSP: 0018:ffff888098cf7558 EFLAGS: 00010246
RAX: 00000000a1c55f2b RBX: ffff8880b500ba80 RCX: ffff88809ac25e18
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88809ac25d40
RBP: ffff888098cf7650 R08: 0000000000000001 R09: ffffed1017444552
R10: 0000000000000000 R11: ffff8880ba222a93 R12: ffff888098b95060
R13: 0000000000000004 R14: ffff888098b94d80 R15: 0000000000000000
FS:  00007fe243fe1700(0000) GS:ffff8880ba200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe738f4f9c CR3: 0000000090405000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400