linux-kernel - [syzbot] [net?] general protection fault in vxlan_vnigroup

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Message-ID: <67a9d9b4.050a0220.110943.002d.GAE@google.com>
Date: Mon, 10 Feb 2025 02:49:24 -0800
From: syzbot <syzbot+6a9624592218c2c5e7aa@...kaller.appspotmail.com>
To: andrew+netdev@...n.ch, davem@...emloft.net, edumazet@...gle.com, 
	kuba@...nel.org, linux-kernel@...r.kernel.org, netdev@...r.kernel.org, 
	pabeni@...hat.com, syzkaller-bugs@...glegroups.com
Subject: [syzbot] [net?] general protection fault in vxlan_vnigroup_uninit

Hello,

syzbot found the following issue on:

HEAD commit:    69b54314c975 Merge tag 'kbuild-fixes-v6.14' of git://git.k..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=124d6bdf980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=a7ddf49cf33ba213
dashboard link: https://syzkaller.appspot.com/bug?extid=6a9624592218c2c5e7aa
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=1466c2a4580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=121f3b18580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-69b54314.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2d0a58d1d655/vmlinux-69b54314.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b99949b40299/bzImage-69b54314.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6a9624592218c2c5e7aa@...kaller.appspotmail.com

RBP: 0000000000000002 R08: 00007ffcf7f2bc26 R09: 00000000000000a0
R10: 0000000000000002 R11: 0000000000000206 R12: 0000400000000114
R13: 0000400000000110 R14: 0000400000000088 R15: 0000000000000001
 </TASK>
Oops: general protection fault, probably for non-canonical address 0xdffffc000000002c: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000160-0x0000000000000167]
CPU: 0 UID: 0 PID: 5952 Comm: syz-executor397 Not tainted 6.14.0-rc1-syzkaller-00276-g69b54314c975 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:vxlan_vnigroup_uninit+0x89/0x500 drivers/net/vxlan/vxlan_vnifilter.c:912
Code: 00 48 8b 44 24 08 4c 8b b0 98 41 00 00 49 8d 86 60 01 00 00 48 89 c2 48 89 44 24 10 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 4d 04 00 00 49 8b 86 60 01 00 00 48 ba 00 00 00
RSP: 0018:ffffc90003f67218 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffffff8672effb
RDX: 000000000000002c RSI: ffffffff8672ecb9 RDI: ffff8880326b4f18
RBP: ffff8880326b4ef4 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000020000
R13: ffff8880326b0d80 R14: 0000000000000000 R15: dffffc0000000000
FS:  0000555568fc8380(0000) GS:ffff88806a600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007faf08e2b246 CR3: 0000000012f30000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 vxlan_uninit+0x1ab/0x200 drivers/net/vxlan/vxlan_core.c:2942
 unregister_netdevice_many_notify+0x12d6/0x1f30 net/core/dev.c:11824
 rtnl_newlink_create net/core/rtnetlink.c:3823 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3906 [inline]
 rtnl_newlink+0x1459/0x1d60 net/core/rtnetlink.c:4021
 rtnetlink_rcv_msg+0x95b/0xea0 net/core/rtnetlink.c:6911
 netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2543
 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]
 netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1348
 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1892
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:733 [inline]
 ____sys_sendmsg+0xaaf/0xc90 net/socket.c:2573
 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2627
 __sys_sendmsg+0x16e/0x220 net/socket.c:2659
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7faf08dd5a69
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 a1 1a 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:00007ffcf7f2be88 EFLAGS: 00000206 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ffcf7f2bea0 RCX: 00007faf08dd5a69
RDX: 0000000004008840 RSI: 0000400000000000 RDI: 0000000000000003
RBP: 0000000000000002 R08: 00007ffcf7f2bc26 R09: 00000000000000a0
R10: 0000000000000002 R11: 0000000000000206 R12: 0000400000000114
R13: 0000400000000110 R14: 0000400000000088 R15: 0000000000000001
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:vxlan_vnigroup_uninit+0x89/0x500 drivers/net/vxlan/vxlan_vnifilter.c:912
Code: 00 48 8b 44 24 08 4c 8b b0 98 41 00 00 49 8d 86 60 01 00 00 48 89 c2 48 89 44 24 10 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 4d 04 00 00 49 8b 86 60 01 00 00 48 ba 00 00 00
RSP: 0018:ffffc90003f67218 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffffff8672effb
RDX: 000000000000002c RSI: ffffffff8672ecb9 RDI: ffff8880326b4f18
RBP: ffff8880326b4ef4 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000020000
R13: ffff8880326b0d80 R14: 0000000000000000 R15: dffffc0000000000
FS:  0000555568fc8380(0000) GS:ffff88806a800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffcf7f2bd88 CR3: 0000000012f30000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	00 48 8b             	add    %cl,-0x75(%rax)
   3:	44 24 08             	rex.R and $0x8,%al
   6:	4c 8b b0 98 41 00 00 	mov    0x4198(%rax),%r14
   d:	49 8d 86 60 01 00 00 	lea    0x160(%r14),%rax
  14:	48 89 c2             	mov    %rax,%rdx
  17:	48 89 44 24 10       	mov    %rax,0x10(%rsp)
  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 4d 04 00 00    	jne    0x481
  34:	49 8b 86 60 01 00 00 	mov    0x160(%r14),%rax
  3b:	48                   	rex.W
  3c:	ba                   	.byte 0xba
  3d:	00 00                	add    %al,(%rax)


---
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