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WARNING in __ip6_make_skb

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: 2105d, last: 2105d
Discussions (1)
Title Replies (including bot) Last reply
[PATCH net] ipv6: use fib6_info_hold_safe() when necessary 4 (4) 2018/07/23 18:25

Sample crash report:
dst_release: dst:(____ptrval____) refcnt:-1
dst_release: dst:(____ptrval____) refcnt:-2
dst_release: dst:(____ptrval____) refcnt:-3
WARNING: CPU: 1 PID: 4792 at include/net/dst.h:239 dst_hold include/net/dst.h:239 [inline]
WARNING: CPU: 1 PID: 4792 at include/net/dst.h:239 dst_clone include/net/dst.h:259 [inline]
WARNING: CPU: 1 PID: 4792 at include/net/dst.h:239 __ip6_make_skb+0x1798/0x21e0 net/ipv6/ip6_output.c:1675
dst_release: dst:(____ptrval____) refcnt:-1
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 4792 Comm: syz-executor089 Not tainted 4.18.0-rc3+ #122
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
 __warn.cold.8+0x163/0x1ba kernel/panic.c:536
 report_bug+0x252/0x2d0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 do_error_trap+0x1fc/0x4d0 arch/x86/kernel/traps.c:296
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316
 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_make_skb+0x1798/0x21e0 net/ipv6/ip6_output.c:1675
Code: 9e fe 0f 00 e9 9e f4 ff ff e8 f4 f4 e2 fa 48 8b 54 24 48 48 8b 74 24 50 48 89 df e8 a2 81 0f 00 e9 0b f4 ff ff e8 d8 f4 e2 fa <0f> 0b e9 68 fc ff ff 48 8d 83 80 00 00 00 4c 8d ab 84 00 00 00 48 
RSP: 0018:ffff8801c89c7090 EFLAGS: 00010293
RAX: ffff8801c8a4e3c0 RBX: ffff8801c957db40 RCX: ffffffff86991304
RDX: 0000000000000000 RSI: ffffffff869916f8 RDI: 0000000000000005
RBP: ffff8801c89c72f8 R08: ffff8801c8a4e3c0 R09: ffffed00359f5ad0
R10: ffffed00359f5ad0 R11: ffff8801acfad683 R12: 0000000000000000
R13: ffff8801acfad680 R14: 1ffff10039138e3a R15: ffff8801acfad640
 ip6_make_skb+0x3b3/0x5e0 net/ipv6/ip6_output.c:1783
 udpv6_sendmsg+0x2d46/0x36b0 net/ipv6/udp.c:1373
 inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:799
 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:00007f7e90d4bda8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00000000006dcc54 RCX: 0000000000446ba9
RDX: 00000000000000b8 RSI: 0000000020001b00 RDI: 0000000000000003
RBP: 00000000006dcc50 R08: 00007f7e90d4c700 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 (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/07/15 05:23 net-next-old 2aa4a3378ad0 92a49505 .config console log report syz C ci-upstream-net-kasan-gce
* Struck through repros no longer work on HEAD.