syzbot


general protection fault in rt6_fill_node

Status: fixed on 2020/11/16 12:12
Reported-by: syzbot+81af6e9b3c4b8bc874f8@syzkaller.appspotmail.com
Fix commit: eeaac3634ee0 net: nexthop: don't allow empty NHA_GROUP
First crash: 832d, last: 832d

Cause bisection: introduced by (bisect log) :
commit 867d03bc238f62fcd28f287b9da8af5e483baeab
Author: Robert Hancock <hancock@sedsystems.ca>
Date: Thu Jun 6 22:28:14 2019 +0000

  net: axienet: Add DMA registers to ethtool register dump

Crash: general protection fault in batadv_iv_ogm_queue_add (log)
Repro: C syz .config

Fix bisection: fixed by (bisect log) :
commit eeaac3634ee0e3f35548be35275efeca888e9b23
Author: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Date: Sat Aug 22 12:06:36 2020 +0000

  net: nexthop: don't allow empty NHA_GROUP

Patch testing requests:
Created Duration User Patch Repo Result
2020/09/02 05:13 17m anant.thazhemadam@gmail.com https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master OK

Sample crash report:
IPv6: RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE
IPv6: NLM_F_CREATE should be set when creating new route
IPv6: NLM_F_CREATE should be set when creating new route
general protection fault, probably for non-canonical address 0xdffffc0000000010: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000080-0x0000000000000087]
CPU: 1 PID: 7086 Comm: syz-executor952 Not tainted 5.9.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:nexthop_is_blackhole include/net/nexthop.h:240 [inline]
RIP: 0010:rt6_fill_node+0x1396/0x2940 net/ipv6/route.c:5584
Code: 3c 02 00 0f 85 ef 14 00 00 4d 8b 6d 10 e8 82 c8 86 fa 49 8d bd 80 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 10 15 00 00 4d 8b ad 80 00 00 00 e8 34 09 06 01
RSP: 0018:ffffc900058972b0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff88808e2f3000 RCX: ffffffff86ed7656
RDX: 0000000000000010 RSI: ffffffff86ed768e RDI: 0000000000000080
RBP: ffffc900058973e8 R08: 0000000000000001 R09: ffff88808e2f3047
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88808e319040
R13: 0000000000000000 R14: ffff88809d30f700 R15: 0000000000000000
FS:  0000000001e77880(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000300 CR3: 000000008dde4000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 inet6_rt_notify+0x14c/0x2b0 net/ipv6/route.c:6017
 fib6_add_rt2node net/ipv6/ip6_fib.c:1246 [inline]
 fib6_add+0x2840/0x3ed0 net/ipv6/ip6_fib.c:1473
 __ip6_ins_rt net/ipv6/route.c:1317 [inline]
 ip6_route_add+0x8b/0x150 net/ipv6/route.c:3744
 inet6_rtm_newroute+0x152/0x160 net/ipv6/route.c:5360
 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5563
 netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2470
 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1330
 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:671
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2353
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2407
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2440
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x443ef9
Code: e8 8c 07 03 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 bb 09 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffdb34aed28 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000443ef9
RDX: 0000000000000000 RSI: 0000000020000300 RDI: 0000000000000003
RBP: 00007ffdb34aed30 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000010f02
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace f3c27c78037a8ebe ]---
RIP: 0010:nexthop_is_blackhole include/net/nexthop.h:240 [inline]
RIP: 0010:rt6_fill_node+0x1396/0x2940 net/ipv6/route.c:5584
Code: 3c 02 00 0f 85 ef 14 00 00 4d 8b 6d 10 e8 82 c8 86 fa 49 8d bd 80 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 10 15 00 00 4d 8b ad 80 00 00 00 e8 34 09 06 01
RSP: 0018:ffffc900058972b0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff88808e2f3000 RCX: ffffffff86ed7656
RDX: 0000000000000010 RSI: ffffffff86ed768e RDI: 0000000000000080
RBP: ffffc900058973e8 R08: 0000000000000001 R09: ffff88808e2f3047
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88808e319040
R13: 0000000000000000 R14: ffff88809d30f700 R15: 0000000000000000
FS:  0000000001e77880(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000300 CR3: 000000008dde4000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (3):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-selinux-root 2020/08/23 20:56 upstream c3d8f220d012 cef5ae68 .config log report syz C
ci-upstream-kasan-gce-root 2020/08/23 19:23 upstream c3d8f220d012 cef5ae68 .config log report syz C
ci-upstream-net-kasan-gce 2020/08/23 17:48 net-next d7223aa58671 cef5ae68 .config log report syz C
* Struck through repros no longer work on HEAD.