syzbot


general protection fault in find_match

Status: upstream: reported on 2025/09/07 13:45
Reported-by: syzbot+e8c6624ed4f30e2c7a6f@syzkaller.appspotmail.com
First crash: 6d17h, last: 2d06h
Similar bugs (11)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in find_match net 2 C done error 10 2037d 2224d 0/29 closed as invalid on 2020/04/17 19:54
upstream general protection fault in find_match (3) net 2 2 1069d 1111d 0/29 auto-obsoleted due to no activity on 2023/01/16 14:40
android-6-1 general protection fault in find_match 2 4 35d 124d 0/2 premoderation: reported on 2025/05/12 10:56
upstream general protection fault in find_match (4) net 2 1 753d 749d 0/29 auto-obsoleted due to no activity on 2023/11/20 22:29
upstream general protection fault in find_match (2) net 2 4 1661d 1726d 0/29 auto-closed as invalid on 2021/06/26 04:02
linux-5.15 BUG: unable to handle kernel paging request in find_match 8 5 114d 169d 0/3 auto-obsoleted due to no activity on 2025/08/31 04:44
android-5-15 general protection fault in find_match 2 7 62d 158d 0/2 premoderation: reported on 2025/04/08 10:01
upstream general protection fault in find_match (5) net 2 2 461d 461d 26/29 fixed on 2024/07/10 10:07
linux-4.19 general protection fault in find_match 2 C error 1 1454d 2152d 0/1 upstream: reported C repro on 2019/10/23 12:46
android-5-10 general protection fault in find_match 2 47 8d10h 162d 0/2 premoderation: reported on 2025/04/04 19:16
linux-6.1 BUG: unable to handle kernel paging request in find_match 8 19 9d10h 108d 0/3 upstream: reported on 2025/05/28 21:21

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc000000006c: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000360-0x0000000000000367]
CPU: 0 PID: 10807 Comm: syz.7.1822 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__in6_dev_get include/net/addrconf.h:321 [inline]
RIP: 0010:ip6_ignore_linkdown include/net/addrconf.h:412 [inline]
RIP: 0010:find_match+0xa3/0xc30 net/ipv6/route.c:744
Code: 00 00 00 00 00 fc ff df 42 80 7c 25 00 00 74 08 48 89 df e8 7f f2 2a f9 48 89 d8 bb 60 03 00 00 48 03 18 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 5e f2 2a f9 48 8b 1b e8 36 b3 17
RSP: 0018:ffffc9000338f2d8 EFLAGS: 00010206
RAX: 000000000000006c RBX: 0000000000000360 RCX: ffff88806856bb80
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 1ffff110033f5f84 R08: ffffc9000338f660 R09: ffffc9000338f670
R10: fffff52000671e9a R11: 1ffff92000671e98 R12: dffffc0000000000
R13: 0000000000000003 R14: 1ffff110033f5f85 R15: ffff888019fafc2f
FS:  00007f9f6f6806c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000000 CR3: 0000000062aa2000 CR4: 00000000003506f0
DR0: 0000000000000002 DR1: 0000000000000005 DR2: 8000000000000000
DR3: 1000000100000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 rt6_nh_find_match+0xd5/0x140 net/ipv6/route.c:784
 nexthop_for_each_fib6_nh+0x1be/0x3e0 net/ipv4/nexthop.c:1242
 __find_rr_leaf+0x45e/0x6c0 net/ipv6/route.c:825
 find_rr_leaf net/ipv6/route.c:853 [inline]
 rt6_select net/ipv6/route.c:897 [inline]
 fib6_table_lookup+0x39c/0xa70 net/ipv6/route.c:2183
 ip6_pol_route+0x209/0x1290 net/ipv6/route.c:2219
 pol_lookup_func include/net/ip6_fib.h:582 [inline]
 fib6_rule_lookup+0x2fc/0x570 net/ipv6/fib6_rules.c:120
 ip6_route_output_flags+0xbf/0x300 net/ipv6/route.c:2640
 ip6_route_output include/net/ip6_route.h:98 [inline]
 ip6_dst_lookup_tail+0x194/0x1200 net/ipv6/ip6_output.c:1101
 ip6_dst_lookup_flow+0x44/0xd0 net/ipv6/ip6_output.c:1231
 ip6_datagram_dst_update+0x699/0xbe0 net/ipv6/datagram.c:89
 __ip6_datagram_connect+0xbc3/0x1120 net/ipv6/datagram.c:248
 ip6_datagram_connect+0x29/0x40 net/ipv6/datagram.c:272
 __sys_connect_file net/socket.c:1923 [inline]
 __sys_connect+0x389/0x410 net/socket.c:1940
 __do_sys_connect net/socket.c:1950 [inline]
 __se_sys_connect net/socket.c:1947 [inline]
 __x64_sys_connect+0x76/0x80 net/socket.c:1947
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f9f71418ba9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9f6f680038 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00007f9f7165ffa0 RCX: 00007f9f71418ba9
RDX: 000000000000001c RSI: 0000200000000000 RDI: 0000000000000003
RBP: 00007f9f7149be19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9f71660038 R14: 00007f9f7165ffa0 R15: 00007ffc7ad60918
 </TASK>
Modules linked in:
---[ end trace f475a919016800f3 ]---
RIP: 0010:__in6_dev_get include/net/addrconf.h:321 [inline]
RIP: 0010:ip6_ignore_linkdown include/net/addrconf.h:412 [inline]
RIP: 0010:find_match+0xa3/0xc30 net/ipv6/route.c:744
Code: 00 00 00 00 00 fc ff df 42 80 7c 25 00 00 74 08 48 89 df e8 7f f2 2a f9 48 89 d8 bb 60 03 00 00 48 03 18 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 5e f2 2a f9 48 8b 1b e8 36 b3 17
RSP: 0018:ffffc9000338f2d8 EFLAGS: 00010206
RAX: 000000000000006c RBX: 0000000000000360 RCX: ffff88806856bb80
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 1ffff110033f5f84 R08: ffffc9000338f660 R09: ffffc9000338f670
R10: fffff52000671e9a R11: 1ffff92000671e98 R12: dffffc0000000000
R13: 0000000000000003 R14: 1ffff110033f5f85 R15: ffff888019fafc2f
FS:  00007f9f6f6806c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2bfe395e9c CR3: 0000000062aa2000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess), 7 bytes skipped:
   0:	df 42 80             	filds  -0x80(%rdx)
   3:	7c 25                	jl     0x2a
   5:	00 00                	add    %al,(%rax)
   7:	74 08                	je     0x11
   9:	48 89 df             	mov    %rbx,%rdi
   c:	e8 7f f2 2a f9       	call   0xf92af290
  11:	48 89 d8             	mov    %rbx,%rax
  14:	bb 60 03 00 00       	mov    $0x360,%ebx
  19:	48 03 18             	add    (%rax),%rbx
  1c:	48 89 d8             	mov    %rbx,%rax
  1f:	48 c1 e8 03          	shr    $0x3,%rax
* 23:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1) <-- trapping instruction
  28:	74 08                	je     0x32
  2a:	48 89 df             	mov    %rbx,%rdi
  2d:	e8 5e f2 2a f9       	call   0xf92af290
  32:	48 8b 1b             	mov    (%rbx),%rbx
  35:	e8                   	.byte 0xe8
  36:	36 b3 17             	ss mov $0x17,%bl

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/12 00:44 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan general protection fault in find_match
2025/09/07 13:44 linux-5.15.y 7a6c2d093c45 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan general protection fault in find_match
* Struck through repros no longer work on HEAD.