kernel BUG at net/phonet/socket.c:LINE!

Hello,

syzbot found the following crash on:

HEAD commit: b93cfb9c net: icmp6: do not select saddr from iif when rou..
git tree: net
console output: https://syzkaller.appspot.com/x/log.txt?x=13501d2be00000
kernel config: https://syzkaller.appspot.com/x/.config?x=94a7f1dec460ee83
dashboard link: https://syzkaller.appspot.com/bug?extid=2dc91e7fc3dea88b1e8a
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: [email protected]

------------[ cut here ]------------
kernel BUG at net/phonet/socket.c:213!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 8394 Comm: syz-executor.4 Not tainted 5.6.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:pn_socket_autobind net/phonet/socket.c:213 [inline]
RIP: 0010:pn_socket_autobind+0x13c/0x160 net/phonet/socket.c:202
Code: 44 05 00 00 00 00 00 44 89 e0 48 8b 4c 24 58 65 48 33 0c 25 28 00 00 00 75 23 48 83 c4 60 5b 5d 41 5c 41 5d c3 e8 b4 ad 41 fa <0f> 0b e8 9d 56 7f fa eb 9f e8 b6 56 7f fa e9 6d ff ff ff e8 0c dd
RSP: 0018:ffffc900034cfda8 EFLAGS: 00010212
RAX: 0000000000040000 RBX: 0000000000000000 RCX: ffffc90011d66000
RDX: 0000000000000081 RSI: ffffffff873183dc RDI: 0000000000000003
RBP: 1ffff92000699fb5 R08: ffff8880620f61c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 00007f84223c9700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004d8730 CR3: 000000005cce0000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
pn_socket_listen+0x40/0x200 net/phonet/socket.c:399
__sys_listen+0x17d/0x250 net/socket.c:1696
__do_sys_listen net/socket.c:1705 [inline]
__se_sys_listen net/socket.c:1703 [inline]
__x64_sys_listen+0x50/0x70 net/socket.c:1703
do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x45c889
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f84223c8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000032
RAX: ffffffffffffffda RBX: 00007f84223c96d4 RCX: 000000000045c889
RDX: 0000000000000000 RSI: 000000000000007d RDI: 0000000000000003
RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000712 R14: 00000000004c9e2d R15: 000000000076bf0c
Modules linked in:
---[ end trace 65d6f1331216c544 ]---
RIP: 0010:pn_socket_autobind net/phonet/socket.c:213 [inline]
RIP: 0010:pn_socket_autobind+0x13c/0x160 net/phonet/socket.c:202
Code: 44 05 00 00 00 00 00 44 89 e0 48 8b 4c 24 58 65 48 33 0c 25 28 00 00 00 75 23 48 83 c4 60 5b 5d 41 5c 41 5d c3 e8 b4 ad 41 fa <0f> 0b e8 9d 56 7f fa eb 9f e8 b6 56 7f fa e9 6d ff ff ff e8 0c dd
RSP: 0018:ffffc900034cfda8 EFLAGS: 00010212
RAX: 0000000000040000 RBX: 0000000000000000 RCX: ffffc90011d66000
RDX: 0000000000000081 RSI: ffffffff873183dc RDI: 0000000000000003
RBP: 1ffff92000699fb5 R08: ffff8880620f61c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 00007f84223c9700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000076c000 CR3: 000000005cce0000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
This bug 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 [email protected].

syzbot will keep track of this bug report. See:
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syzbot has found a reproducer for the following issue on:

HEAD commit: 60ec7fcfe768 qlcnic: potential dereference null pointer of..
git tree: net
console output: https://syzkaller.appspot.com/x/log.txt?x=11b3505db00000
kernel config: https://syzkaller.appspot.com/x/.config?x=fa556098924b78f0
dashboard link: https://syzkaller.appspot.com/bug?extid=2dc91e7fc3dea88b1e8a
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=168791cdb00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14a0cbcdb00000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]

netlink: 'syz-executor185': attribute type 2 has an invalid length.
CPU: 0 PID: 3620 Comm: syz-executor185 Not tainted 5.16.0-rc5-syzkaller #0
RIP: 0010:pn_socket_autobind net/phonet/socket.c:213 [inline] net/phonet/socket.c:202
RIP: 0010:pn_socket_autobind+0x13c/0x160 net/phonet/socket.c:202 net/phonet/socket.c:202
Code: 44 05 00 00 00 00 00 48 8b 44 24 58 65 48 2b 04 25 28 00 00 00 75 26 48 83 c4 60 44 89 e0 5b 5d 41 5c 41 5d c3 e8 64 60 1e f9 <0f> 0b e8 2d 25 65 f9 eb 9f e8 46 25 65 f9 e9 6d ff ff ff e8 8c 2b
RSP: 0018:ffffc90001bafc40 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88801c748000 RSI: ffffffff8859516c RDI: 0000000000000003
RBP: 1ffff92000375f88 R08: 00000000ffffffea R09: 0000000000000000
R10: ffffffff8859512c R11: 0000000000000000 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff88801c748000
FS: 0000555556878300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CR2: 0000000020000740 CR3: 0000000018a78000 CR4: 00000000003506f0
<TASK>
pn_socket_connect+0xfc/0x970 net/phonet/socket.c:227 net/phonet/socket.c:227
__sys_connect_file+0x155/0x1a0 net/socket.c:1896 net/socket.c:1896
__sys_connect+0x161/0x190 net/socket.c:1913 net/socket.c:1913
__do_sys_connect net/socket.c:1923 [inline]
__se_sys_connect net/socket.c:1920 [inline]
__do_sys_connect net/socket.c:1923 [inline] net/socket.c:1920
__se_sys_connect net/socket.c:1920 [inline] net/socket.c:1920
__x64_sys_connect+0x6f/0xb0 net/socket.c:1920 net/socket.c:1920
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_x64 arch/x86/entry/common.c:50 [inline] arch/x86/entry/common.c:80
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f9bf1080159
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff1adca428 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f9bf1080159
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000013355
R13: 00007fff1adca490 R14: 00007fff1adca480 R15: 00007fff1adca44c
</TASK>
Modules linked in:
---[ end trace 16a4e3e11e1ba5b9 ]---
RIP: 0010:pn_socket_autobind net/phonet/socket.c:213 [inline] net/phonet/socket.c:202
RIP: 0010:pn_socket_autobind+0x13c/0x160 net/phonet/socket.c:202 net/phonet/socket.c:202
Code: 44 05 00 00 00 00 00 48 8b 44 24 58 65 48 2b 04 25 28 00 00 00 75 26 48 83 c4 60 44 89 e0 5b 5d 41 5c 41 5d c3 e8 64 60 1e f9 <0f> 0b e8 2d 25 65 f9 eb 9f e8 46 25 65 f9 e9 6d ff ff ff e8 8c 2b
RSP: 0018:ffffc90001bafc40 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88801c748000 RSI: ffffffff8859516c RDI: 0000000000000003
RBP: 1ffff92000375f88 R08: 00000000ffffffea R09: 0000000000000000
R10: ffffffff8859512c R11: 0000000000000000 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff88801c748000
FS: 0000555556878300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CR2: 0000000020000740 CR3: 0000000018a78000 CR4: 00000000003506f0

This bug can be triggered via simple

sk = socket(AF_PHONET)
ioctl(sk, SIOCPNENABLEPIPE, 0)
connect(sk);


ioctl() sets sk->sk_state to TCP_SYN_SENT in pep_sock_enable() and then
there is following check in pn_socket_bind():

if (sk->sk_state != TCP_CLOSE || pn_port(pn->sobject)) {
err = -EINVAL; /* attempt to rebind */
goto out;
}

Looks like "sk->sk_state != TCP_CLOSE" check is redundant and
pn_port(pn->sobject) is unique flag, that socket is already binded.




With regards,
Pavel Skripkin