[syzbot] [net?] general protection fault in arp_create (3)

[syzbot <syzbot+3b1dd14b3a62374e75c7@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    7ee983c850b4 Merge tag 'drm-fixes-2025-02-08' of https://g..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=127b61b0580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=147b7d49d83b8036
dashboard link: https://syzkaller.appspot.com/bug?extid=3b1dd14b3a62374e75c7
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/54ead761f64f/disk-7ee983c8.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/95e57de2a045/vmlinux-7ee983c8.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d24a612a8ac7/bzImage-7ee983c8.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3b1dd14b3a62374e75c7@syzkaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000016: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x00000000000000b0-0x00000000000000b7]
CPU: 1 UID: 0 PID: 3448 Comm: kworker/u8:9 Not tainted 6.14.0-rc1-syzkaller-00181-g7ee983c850b4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Workqueue: bat_events batadv_bla_periodic_work
RIP: 0010:arp_create+0x46/0x910 net/ipv4/arp.c:554
Code: 49 89 ce 89 54 24 3c 89 74 24 30 89 fb 49 bd 00 00 00 00 00 fc ff df e8 18 e6 62 f7 49 8d be b4 00 00 00 48 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 db 05 00 00 45 0f b7 a6 b4 00 00 00 49
RSP: 0018:ffffc9000c3a7870 EFLAGS: 00010203
RAX: 0000000000000016 RBX: 0000000000000002 RCX: ffff888031bcbc00
RDX: 0000000000000000 RSI: 0000000000000806 RDI: 00000000000000b4
RBP: ffffc9000c3a79f0 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff52001874f30 R12: ffffc9000c3a7aa0
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4b41e61fa8 CR3: 000000007e55a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 batadv_bla_send_claim+0x16f/0xea0 net/batman-adv/bridge_loop_avoidance.c:361
 batadv_bla_send_announce net/batman-adv/bridge_loop_avoidance.c:675 [inline]
 batadv_bla_periodic_work+0x5dc/0xaf0 net/batman-adv/bridge_loop_avoidance.c:1481
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317
 worker_thread+0x870/0xd30 kernel/workqueue.c:3398
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:arp_create+0x46/0x910 net/ipv4/arp.c:554
Code: 49 89 ce 89 54 24 3c 89 74 24 30 89 fb 49 bd 00 00 00 00 00 fc ff df e8 18 e6 62 f7 49 8d be b4 00 00 00 48 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 db 05 00 00 45 0f b7 a6 b4 00 00 00 49
RSP: 0018:ffffc9000c3a7870 EFLAGS: 00010203
RAX: 0000000000000016 RBX: 0000000000000002 RCX: ffff888031bcbc00
RDX: 0000000000000000 RSI: 0000000000000806 RDI: 00000000000000b4
RBP: ffffc9000c3a79f0 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff52001874f30 R12: ffffc9000c3a7aa0
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4b41e61fa8 CR3: 00000000348fa000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	49 89 ce             	mov    %rcx,%r14
   3:	89 54 24 3c          	mov    %edx,0x3c(%rsp)
   7:	89 74 24 30          	mov    %esi,0x30(%rsp)
   b:	89 fb                	mov    %edi,%ebx
   d:	49 bd 00 00 00 00 00 	movabs $0xdffffc0000000000,%r13
  14:	fc ff df
  17:	e8 18 e6 62 f7       	call   0xf762e634
  1c:	49 8d be b4 00 00 00 	lea    0xb4(%r14),%rdi
  23:	48 89 f8             	mov    %rdi,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 0f b6 04 28       	movzbl (%rax,%r13,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	0f 85 db 05 00 00    	jne    0x612
  37:	45 0f b7 a6 b4 00 00 	movzwl 0xb4(%r14),%r12d
  3e:	00
  3f:	49                   	rex.WB


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