[syzbot] [openvswitch?] BUG: unable to handle kernel paging request in ovs_vport_add

From: syzbot
Date: Fri Aug 11 2023 - 09:59:05 EST

Hello,

syzbot found the following issue on:

HEAD commit: 29afcd69672a Merge branch 'improve-the-taprio-qdisc-s-rela..
git tree: net-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1056d29da80000
kernel config: https://syzkaller.appspot.com/x/.config?x=1199967d15d20915
dashboard link: https://syzkaller.appspot.com/bug?extid=7456b5dcf65111553320
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=110bf169a80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=104f7a9da80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/df7b1d334282/disk-29afcd69.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/178397c497e2/vmlinux-29afcd69.xz
kernel image: https://storage.googleapis.com/syzbot-assets/38ffbedb3b50/bzImage-29afcd69.xz

The issue was bisected to:

commit 759ab1edb56c88906830fd6b2e7b12514dd32758
Author: Jakub Kicinski <kuba@xxxxxxxxxx>
Date: Wed Jul 26 18:55:29 2023 +0000

net: store netdevs in an xarray

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1431ba3da80000
final oops: https://syzkaller.appspot.com/x/report.txt?x=1631ba3da80000
console output: https://syzkaller.appspot.com/x/log.txt?x=1231ba3da80000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7456b5dcf65111553320@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 759ab1edb56c ("net: store netdevs in an xarray")

netlink: 'syz-executor294': attribute type 9 has an invalid length.
BUG: unable to handle page fault for address: fffffbfff412f978
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 23ffe4067 P4D 23ffe4067 PUD 23ffe3067 PMD 19e75067 PTE 0
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 5027 Comm: syz-executor294 Not tainted 6.5.0-rc4-syzkaller-01306-g29afcd69672a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
RIP: 0010:ovs_vport_name net/openvswitch/vport.h:196 [inline]
RIP: 0010:ovs_vport_add+0x17a/0x4c0 net/openvswitch/vport.c:223
Code: 89 c6 e8 39 16 78 f7 48 81 fd 00 f0 ff ff 0f 87 5b 02 00 00 e8 97 1a 78 f7 48 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 11 03 00 00 48 8d 7d 10 48 8b 75 00 48 b8 00 00
RSP: 0018:ffffc900038f73d0 EFLAGS: 00010a06
RAX: dffffc0000000000 RBX: ffffffff8e8df240 RCX: 0000000000000000
RDX: 1ffffffff412f978 RSI: ffffffff8a0e0579 RDI: 0000000000000007
RBP: ffffffffa097cbc2 R08: 0000000000000007 R09: fffffffffffff000
R10: ffffffffa097cbc2 R11: ffffffff8a40008b R12: ffffffff8e8df270
R13: dffffc0000000000 R14: ffffc900038f74d0 R15: ffffc900038f74d8
FS: 0000555556e67380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffbfff412f978 CR3: 000000007ab37000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
new_vport+0x16/0x1c0 net/openvswitch/datapath.c:203
ovs_dp_cmd_new+0x6a1/0xe70 net/openvswitch/datapath.c:1841
genl_family_rcv_msg_doit.isra.0+0x1ef/0x2d0 net/netlink/genetlink.c:974
genl_family_rcv_msg net/netlink/genetlink.c:1054 [inline]
genl_rcv_msg+0x559/0x800 net/netlink/genetlink.c:1071
netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2575
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1082
netlink_unicast_kernel net/netlink/af_netlink.c:1344 [inline]
netlink_unicast+0x539/0x800 net/netlink/af_netlink.c:1370
netlink_sendmsg+0x93c/0xe40 net/netlink/af_netlink.c:1939
sock_sendmsg_nosec net/socket.c:728 [inline]
sock_sendmsg+0xd9/0x180 net/socket.c:751
____sys_sendmsg+0x6ac/0x940 net/socket.c:2514
___sys_sendmsg+0x135/0x1d0 net/socket.c:2568
__sys_sendmsg+0x117/0x1e0 net/socket.c:2597
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fa80bfd7569
Code: 48 83 c4 28 c3 e8 37 17 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdf3beb468 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ffdf3beb638 RCX: 00007fa80bfd7569
RDX: 0000000000000000 RSI: 0000000020000100 RDI: 0000000000000003
RBP: 00007fa80c04b610 R08: 000000000000000c R09: 00007ffdf3beb638
R10: 0000000000001004 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffdf3beb628 R14: 0000000000000001 R15: 0000000000000001
</TASK>
Modules linked in:
CR2: fffffbfff412f978
---[ end trace 0000000000000000 ]---
RIP: 0010:ovs_vport_name net/openvswitch/vport.h:196 [inline]
RIP: 0010:ovs_vport_add+0x17a/0x4c0 net/openvswitch/vport.c:223
Code: 89 c6 e8 39 16 78 f7 48 81 fd 00 f0 ff ff 0f 87 5b 02 00 00 e8 97 1a 78 f7 48 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 11 03 00 00 48 8d 7d 10 48 8b 75 00 48 b8 00 00
RSP: 0018:ffffc900038f73d0 EFLAGS: 00010a06
RAX: dffffc0000000000 RBX: ffffffff8e8df240 RCX: 0000000000000000
RDX: 1ffffffff412f978 RSI: ffffffff8a0e0579 RDI: 0000000000000007
RBP: ffffffffa097cbc2 R08: 0000000000000007 R09: fffffffffffff000
R10: ffffffffa097cbc2 R11: ffffffff8a40008b R12: ffffffff8e8df270
R13: dffffc0000000000 R14: ffffc900038f74d0 R15: ffffc900038f74d8
FS: 0000555556e67380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffbfff412f978 CR3: 000000007ab37000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 89 c6 mov %eax,%esi
2: e8 39 16 78 f7 call 0xf7781640
7: 48 81 fd 00 f0 ff ff cmp $0xfffffffffffff000,%rbp
e: 0f 87 5b 02 00 00 ja 0x26f
14: e8 97 1a 78 f7 call 0xf7781ab0
19: 48 89 ea mov %rbp,%rdx
1c: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
23: fc ff df
26: 48 c1 ea 03 shr $0x3,%rdx
* 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction
2e: 0f 85 11 03 00 00 jne 0x345
34: 48 8d 7d 10 lea 0x10(%rbp),%rdi
38: 48 8b 75 00 mov 0x0(%rbp),%rsi
3c: 48 rex.W
3d: b8 .byte 0xb8


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