[syzbot] KASAN: use-after-free Read in icmpv6_sk_exit (2)

From: syzbot
Date: Wed Oct 06 2021 - 03:32:27 EST


Hello,

syzbot found the following issue on:

HEAD commit: 84b3e42564ac Merge tag 'media/v5.15-3' of git://git.kernel..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12bd85df300000
kernel config: https://syzkaller.appspot.com/x/.config?x=bb467ad25fcc6899
dashboard link: https://syzkaller.appspot.com/bug?extid=497d3e91eb557f7dc0aa
compiler: Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13753e7b300000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+497d3e91eb557f7dc0aa@xxxxxxxxxxxxxxxxxxxxxxxxx

general protection fault, probably for non-canonical address 0xdffffc0000000090: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000480-0x0000000000000487]
CPU: 0 PID: 8 Comm: kworker/u4:0 Not tainted 5.15.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
RIP: 0010:inet_ctl_sock_destroy include/net/inet_common.h:65 [inline]
RIP: 0010:icmpv6_sk_exit+0x106/0x1f0 net/ipv6/icmp.c:1038
Code: 42 80 3c 20 00 74 08 48 89 df e8 e5 7a f3 f8 48 8b 1b 48 85 db 74 2d e8 c8 0d a8 f8 48 81 c3 80 04 00 00 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 bb 7a f3 f8 48 8b 3b e8 f3 30 25
RSP: 0018:ffffc90000cd7b40 EFLAGS: 00010206
RAX: 0000000000000090 RBX: 0000000000000481 RCX: ffff888012375580
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000008
RBP: ffffffff8c38a7d8 R08: ffffffff88da6485 R09: ffffffff843540e0
R10: 0000000000000009 R11: ffff888012375580 R12: dffffc0000000000
R13: 1ffffffff1bb7fbf R14: ffff88801fcf3fe0 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005606aea732f8 CR3: 000000005c17f000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
ops_exit_list net/core/net_namespace.c:168 [inline]
cleanup_net+0x758/0xc50 net/core/net_namespace.c:591
process_one_work+0x853/0x1140 kernel/workqueue.c:2297
worker_thread+0xac1/0x1320 kernel/workqueue.c:2444
kthread+0x453/0x480 kernel/kthread.c:319
ret_from_fork+0x1f/0x30
Modules linked in:
---[ end trace e9d83564f5107008 ]---
RIP: 0010:inet_ctl_sock_destroy include/net/inet_common.h:65 [inline]
RIP: 0010:icmpv6_sk_exit+0x106/0x1f0 net/ipv6/icmp.c:1038
Code: 42 80 3c 20 00 74 08 48 89 df e8 e5 7a f3 f8 48 8b 1b 48 85 db 74 2d e8 c8 0d a8 f8 48 81 c3 80 04 00 00 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 bb 7a f3 f8 48 8b 3b e8 f3 30 25
RSP: 0018:ffffc90000cd7b40 EFLAGS: 00010206
RAX: 0000000000000090 RBX: 0000000000000481 RCX: ffff888012375580
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000008
RBP: ffffffff8c38a7d8 R08: ffffffff88da6485 R09: ffffffff843540e0
R10: 0000000000000009 R11: ffff888012375580 R12: dffffc0000000000
R13: 1ffffffff1bb7fbf R14: ffff88801fcf3fe0 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f93fc5792d8 CR3: 000000005c17f000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1)
5: 74 08 je 0xf
7: 48 89 df mov %rbx,%rdi
a: e8 e5 7a f3 f8 callq 0xf8f37af4
f: 48 8b 1b mov (%rbx),%rbx
12: 48 85 db test %rbx,%rbx
15: 74 2d je 0x44
17: e8 c8 0d a8 f8 callq 0xf8a80de4
1c: 48 81 c3 80 04 00 00 add $0x480,%rbx
23: 48 89 d8 mov %rbx,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 48 89 df mov %rbx,%rdi
34: e8 bb 7a f3 f8 callq 0xf8f37af4
39: 48 8b 3b mov (%rbx),%rdi
3c: e8 .byte 0xe8
3d: f3 repz
3e: 30 .byte 0x30
3f: 25 .byte 0x25


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches