syzbot


WARNING in ip6_sk_dst_lookup_flow

Status: fixed on 2018/08/08 18:10
Subsystems: net
[Documentation on labels]
Fix commit: e873e4b9cc7e ipv6: use fib6_info_hold_safe() when necessary
First crash: 2081d, last: 2064d

Sample crash report:
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
8021q: adding VLAN 0 to HW filter on device team0
dst_release: dst:(____ptrval____) refcnt:-1
WARNING: CPU: 0 PID: 4872 at include/net/dst.h:239 dst_hold include/net/dst.h:239 [inline]
WARNING: CPU: 0 PID: 4872 at include/net/dst.h:239 dst_clone include/net/dst.h:259 [inline]
WARNING: CPU: 0 PID: 4872 at include/net/dst.h:239 ip6_sk_dst_lookup_flow+0x8cc/0xac0 net/ipv6/ip6_output.c:1117
dst_release: dst:(____ptrval____) refcnt:-1
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 4872 Comm: syz-executor919 Not tainted 4.18.0-rc5+ #150
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
dst_release: dst:(____ptrval____) refcnt:-2
 panic+0x238/0x4e7 kernel/panic.c:184
dst_release: dst:(____ptrval____) refcnt:-3
 __warn.cold.8+0x163/0x1ba kernel/panic.c:536
 report_bug+0x252/0x2d0 lib/bug.c:186
dst_release: dst:(____ptrval____) refcnt:-4
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 do_error_trap+0x1fc/0x4d0 arch/x86/kernel/traps.c:296
dst_release: dst:(____ptrval____) refcnt:-5
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316
dst_release: dst:(____ptrval____) refcnt:-6
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992
RIP: 0010:dst_hold include/net/dst.h:239 [inline]
RIP: 0010:dst_clone include/net/dst.h:259 [inline]
RIP: 0010:ip6_sk_dst_lookup_flow+0x8cc/0xac0 net/ipv6/ip6_output.c:1117
Code: ff 4c 
dst_release: dst:(____ptrval____) refcnt:-7
89 ff e8 f5 c7 22 fb e9 56 f9 ff ff e8 0b c8 22 fb e9 c1 f9 ff 
dst_release: dst:(____ptrval____) refcnt:-8
ff 4c 89 ef e8 fe c7 22 fb e9 2c fc ff ff 
dst_release: dst:(____ptrval____) refcnt:-9
e8 f4 e8 e4 fa <0f> 0b e9 16 fe ff ff e8 08 c8 22 fb e9 04 f9 ff ff e8 4e 10 b0 fa 
RSP: 0018:ffff8801ca9ef3a0 EFLAGS: 00010293
RAX: ffff8801c69aa700 RBX: ffff8801b2adb200 RCX: ffffffff8697202f
RDX: 0000000000000000 RSI: ffffffff8697224c RDI: 0000000000000005
RBP: ffff8801ca9ef450 R08: ffff8801c69aa700 R09: ffffed003655b648
R10: ffffed003655b648 R11: ffff8801b2adb243 R12: ffff8801be0c57c0
R13: ffff8801ca9ef6a0 R14: 0000000000000000 R15: ffff8801b2adb240
 udpv6_sendmsg+0x20f9/0x35f0 net/ipv6/udp.c:1357
 inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:641 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:651
 ___sys_sendmsg+0x51d/0x930 net/socket.c:2125
 __sys_sendmmsg+0x240/0x6f0 net/socket.c:2220
 __do_sys_sendmmsg net/socket.c:2249 [inline]
 __se_sys_sendmmsg net/socket.c:2246 [inline]
 __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2246
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x446ba9
Code: e8 cc bb 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 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 0f 83 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00 
RSP: 002b:00007f4010c09da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00000000006dcc54 RCX: 0000000000446ba9
RDX: 00000000000000b8 RSI: 0000000020001b00 RDI: 0000000000000003
RBP: 00000000006dcc50 R08: 00007f4010c0a700 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 45c828efc7a64843
R13: e6eeb815b9d8a477 R14: 5068caf6f713c6fc R15: 0000000000000001
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/07/16 21:39 upstream 706bf68b4339 40cb0c9a .config console log report syz C ci-upstream-kasan-gce-root
2018/08/03 04:06 net-old e30cb13c5a09 5b7e23bb .config console log report syz C ci-upstream-net-this-kasan-gce
* Struck through repros no longer work on HEAD.