bisecting fixing commit since c3038e718a19fc596f7b1baba0f83d5146dc7784
building syzkaller on d0686497a9ccb558957ad69ffc9577dd80031b29
testing commit c3038e718a19fc596f7b1baba0f83d5146dc7784 with gcc (GCC) 8.4.1 20210217
kernel signature: a32dadb45c638f4966a151a2aac6aaf6182406f79ddb03fbcb157f11e06cb2a8
run #0: crashed: general protection fault in find_match
run #1: crashed: general protection fault in find_match
run #2: crashed: general protection fault in find_match
run #3: crashed: general protection fault in find_match
run #4: crashed: general protection fault in find_match
run #5: crashed: general protection fault in find_match
run #6: crashed: general protection fault in find_match
run #7: crashed: general protection fault in find_match
run #8: crashed: general protection fault in find_match
run #9: crashed: general protection fault in find_match
run #10: crashed: general protection fault in find_match
run #11: crashed: general protection fault in find_match
run #12: crashed: general protection fault in find_match
run #13: crashed: general protection fault in find_match
run #14: crashed: general protection fault in find_match
run #15: crashed: general protection fault in find_match
run #16: crashed: general protection fault in find_match
run #17: crashed: general protection fault in find_match
run #18: crashed: general protection fault in find_match
run #19: OK
testing current HEAD 125222814e7b8f84df767d6ab622aff2a6d2f234
testing commit 125222814e7b8f84df767d6ab622aff2a6d2f234 with gcc (GCC) 8.4.1 20210217
kernel signature: 782c5c3e77560797330109987b8eb467cbda7ac84930c144ace476a8a770058e
run #0: crashed: general protection fault in find_match
run #1: crashed: general protection fault in find_match
run #2: crashed: general protection fault in find_match
run #3: OK
run #4: OK
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
reproducer seems to be flaky
Reproducer flagged being flaky
revisions tested: 2, total time: 38m19.464469258s (build: 15m18.616929202s, test: 22m32.736591434s)
the crash still happens on HEAD
commit msg: Linux 4.19.182
crash: general protection fault in find_match
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_hsr: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 20105 Comm: syz-executor427 Not tainted 4.19.182-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:fib6_ignore_linkdown net/ipv6/route.c:657 [inline]
RIP: 0010:find_match+0x119/0xd90 net/ipv6/route.c:673
Code: 4d c0 84 c0 4c 8b 45 b8 44 8b 5d b0 0f 84 1b 05 00 00 49 8d b8 3c 02 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 e8
RSP: 0018:ffff8881d4b4ef90 EFLAGS: 00010207
RAX: dffffc0000000000 RBX: ffff8881f3a80540 RCX: ffff8881f3a80600
RDX: 0000000000000047 RSI: ffffffff88197ee0 RDI: 000000000000023c
RBP: ffff8881d4b4f008 R08: 0000000000000000 R09: ffffed103ed04732
R10: ffffed103ed04732 R11: 0000000000000000 R12: ffff8881d4b4f100
R13: 0000000000000003 R14: ffff8881d4b4f0c0 R15: ffff8881f3a805f0
FS:  00007fe124659700(0000) GS:ffff8881f6800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffead5d5a10 CR3: 00000001d82b6005 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 find_rr_leaf net/ipv6/route.c:719 [inline]
 rt6_select net/ipv6/route.c:769 [inline]
 fib6_table_lookup+0x39b/0xae0 net/ipv6/route.c:1876
 ip6_pol_route+0x14b/0x8f0 net/ipv6/route.c:1909
 ip6_pol_route_output+0x3c/0x70 net/ipv6/route.c:2135
 fib6_rule_lookup+0x104/0x480 net/ipv6/fib6_rules.c:118
 ip6_route_output_flags+0x22a/0x2c0 net/ipv6/route.c:2163
 ip6_dst_lookup_tail+0x450/0x1620 net/ipv6/ip6_output.c:1017
 ip6_dst_lookup_flow+0x83/0x170 net/ipv6/ip6_output.c:1118
 ip6_sk_dst_lookup_flow net/ipv6/ip6_output.c:1156 [inline]
 ip6_sk_dst_lookup_flow+0x4e9/0xb50 net/ipv6/ip6_output.c:1146
 udpv6_sendmsg+0x1472/0x2bf0 net/ipv6/udp.c:1386
 inet_sendmsg+0x108/0x440 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg+0xb5/0xf0 net/socket.c:632
 ___sys_sendmsg+0x28e/0x950 net/socket.c:2115
 __sys_sendmmsg+0x160/0x370 net/socket.c:2210
 __do_sys_sendmmsg net/socket.c:2239 [inline]
 __se_sys_sendmmsg net/socket.c:2236 [inline]
 __x64_sys_sendmmsg+0x98/0x100 net/socket.c:2236
 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x446ff9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 a1 15 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe124659318 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00000000004cc4e8 RCX: 0000000000446ff9
RDX: 00000000000000c6 RSI: 0000000020006d00 RDI: 0000000000000004
RBP: 00000000004cc4e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000049c324
R13: 00007ffead597c2f R14: 00007fe124659400 R15: 0000000000022000
Modules linked in:
---[ end trace cdb05c4efde5c824 ]---
RIP: 0010:fib6_ignore_linkdown net/ipv6/route.c:657 [inline]
RIP: 0010:find_match+0x119/0xd90 net/ipv6/route.c:673
Code: 4d c0 84 c0 4c 8b 45 b8 44 8b 5d b0 0f 84 1b 05 00 00 49 8d b8 3c 02 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 e8
RSP: 0018:ffff8881d4b4ef90 EFLAGS: 00010207
RAX: dffffc0000000000 RBX: ffff8881f3a80540 RCX: ffff8881f3a80600
RDX: 0000000000000047 RSI: ffffffff88197ee0 RDI: 000000000000023c
RBP: ffff8881d4b4f008 R08: 0000000000000000 R09: ffffed103ed04732
R10: ffffed103ed04732 R11: 0000000000000000 R12: ffff8881d4b4f100
R13: 0000000000000003 R14: ffff8881d4b4f0c0 R15: ffff8881f3a805f0
FS:  00007fe124659700(0000) GS:ffff8881f6800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffead5d5a10 CR3: 00000001d82b6004 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400