syzbot


general protection fault in arp_create (4)

Status: moderation: reported on 2026/05/17 13:56
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+f8c1872e82ba92d160a4@syzkaller.appspotmail.com
First crash: 4d02h, last: 1d20h
Similar bugs (7)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in arp_create (2) net 2 1 534d 534d 0/29 closed as invalid on 2025/01/02 16:12
upstream KASAN: slab-use-after-free Write in arp_create net 22 2 60d 129d 29/29 fixed on 2026/05/06 16:40
linux-5.15 general protection fault in arp_create 2 1 606d 606d 0/3 auto-obsoleted due to no activity on 2024/12/27 05:27
linux-6.1 general protection fault in arp_create 2 1 509d 509d 0/3 auto-obsoleted due to no activity on 2025/04/02 22:52
upstream general protection fault in arp_create net 8 3 666d 755d 0/29 auto-obsoleted due to no activity on 2024/10/17 18:02
upstream general protection fault in arp_create (3) net 2 4 428d 460d 0/29 auto-obsoleted due to no activity on 2025/06/23 14:12
linux-6.1 BUG: unable to handle kernel paging request in arp_create 8 1 61d 61d 0/3 upstream: reported on 2026/03/17 09:46

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000016: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x00000000000000b0-0x00000000000000b7]
CPU: 1 UID: 0 PID: 37 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: bat_events batadv_bla_periodic_work
RIP: 0010:arp_create+0xb1/0x980 net/ipv4/arp.c:554
Code: 89 4c 24 78 4a 89 04 21 e8 8c f7 a0 f7 44 89 b4 24 a0 00 00 00 89 9c 24 b0 00 00 00 49 8d bf b4 00 00 00 48 89 f8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 15 06 00 00 41 0f b7 9f b4 00 00 00 49
RSP: 0018:ffffc90000ad7720 EFLAGS: 00010213
RAX: 0000000000000016 RBX: 0000000000000000 RCX: ffff8880202edc40
RDX: 0000000000000000 RSI: 0000000000000806 RDI: 00000000000000b4
RBP: ffffc90000ad7840 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff5200015af20 R12: dffffc0000000000
R13: ffff88806501d0a0 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88812538a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000032000 CR3: 0000000022ee7000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 batadv_bla_send_claim+0x183/0xeb0 net/batman-adv/bridge_loop_avoidance.c:361
 batadv_bla_send_loopdetect net/batman-adv/bridge_loop_avoidance.c:1402 [inline]
 batadv_bla_periodic_work+0x654/0xae0 net/batman-adv/bridge_loop_avoidance.c:1492
 process_one_work kernel/workqueue.c:3314 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
 kthread+0x389/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:arp_create+0xb1/0x980 net/ipv4/arp.c:554
Code: 89 4c 24 78 4a 89 04 21 e8 8c f7 a0 f7 44 89 b4 24 a0 00 00 00 89 9c 24 b0 00 00 00 49 8d bf b4 00 00 00 48 89 f8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 15 06 00 00 41 0f b7 9f b4 00 00 00 49
RSP: 0018:ffffc90000ad7720 EFLAGS: 00010213
RAX: 0000000000000016 RBX: 0000000000000000 RCX: ffff8880202edc40
RDX: 0000000000000000 RSI: 0000000000000806 RDI: 00000000000000b4
RBP: ffffc90000ad7840 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff5200015af20 R12: dffffc0000000000
R13: ffff88806501d0a0 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88812538a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000032000 CR3: 0000000022ee7000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess):
   0:	89 4c 24 78          	mov    %ecx,0x78(%rsp)
   4:	4a 89 04 21          	mov    %rax,(%rcx,%r12,1)
   8:	e8 8c f7 a0 f7       	call   0xf7a0f799
   d:	44 89 b4 24 a0 00 00 	mov    %r14d,0xa0(%rsp)
  14:	00
  15:	89 9c 24 b0 00 00 00 	mov    %ebx,0xb0(%rsp)
  1c:	49 8d bf b4 00 00 00 	lea    0xb4(%r15),%rdi
  23:	48 89 f8             	mov    %rdi,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	0f 85 15 06 00 00    	jne    0x64c
  37:	41 0f b7 9f b4 00 00 	movzwl 0xb4(%r15),%ebx
  3e:	00
  3f:	49                   	rex.WB

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/15 19:59 upstream 70eda68668d1 9cd3beaa .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root general protection fault in arp_create
2026/05/13 13:50 upstream 1d5dcaa3bd65 fec2a7ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root general protection fault in arp_create
* Struck through repros no longer work on HEAD.