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general protection fault in add_grec

Status: closed as invalid on 2025/03/17 11:18
Subsystems: net
[Documentation on labels]
First crash: 142d, last: 137d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in add_grec (2) net 3 10d 23d 0/29 upstream: reported on 2025/06/10 08:01
upstream BUG: unable to handle kernel NULL pointer dereference in add_grec net 2 954d 976d 0/29 closed as invalid on 2023/02/17 17:35

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xedec67ed6e4deeec: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: maybe wild-memory-access in range [0x6f635f6b726f7760-0x6f635f6b726f7767]
CPU: 0 UID: 0 PID: 8 Comm: kworker/0:0 Not tainted 6.14.0-rc2-syzkaller-00303-gad1b832bf1cf #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: mld mld_dad_work
RIP: 0010:add_grec+0xed/0x19a0 net/ipv6/mcast.c:1933
Code: 00 74 0f 48 8b 7c 24 48 e8 b0 54 7b f7 48 8b 4c 24 48 48 8b 19 48 83 c3 38 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 0f 85 1e 16 00 00 8b 1b bf 00 05 00 00 89 de e8
RSP: 0018:ffffc900001a79b0 EFLAGS: 00010202
RAX: 0dec6bed6e4deeec RBX: 6f635f6b726f7760 RCX: dffffc0000000000
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: dffffc0000000000 R08: ffffffff8aada3d5 R09: 0000000000000001
R10: 00000000000002ff R11: 18aaaaff01000000 R12: ffff888044407400
R13: ffff8880444074f0 R14: ffff888052964780 R15: 0000000000000004
FS:  0000000000000000(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005631f998c098 CR3: 0000000044710000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 mld_send_initial_cr+0x228/0x4b0 net/ipv6/mcast.c:2282
 mld_dad_work+0x44/0x500 net/ipv6/mcast.c:2308
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xabe/0x18e0 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 ]---
----------------
Code disassembly (best guess):
   0:	00 74 0f 48          	add    %dh,0x48(%rdi,%rcx,1)
   4:	8b 7c 24 48          	mov    0x48(%rsp),%edi
   8:	e8 b0 54 7b f7       	call   0xf77b54bd
   d:	48 8b 4c 24 48       	mov    0x48(%rsp),%rcx
  12:	48 8b 19             	mov    (%rcx),%rbx
  15:	48 83 c3 38          	add    $0x38,%rbx
  19:	48 89 d8             	mov    %rbx,%rax
  1c:	48 c1 e8 03          	shr    $0x3,%rax
  20:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  27:	fc ff df
* 2a:	0f b6 04 08          	movzbl (%rax,%rcx,1),%eax <-- trapping instruction
  2e:	84 c0                	test   %al,%al
  30:	0f 85 1e 16 00 00    	jne    0x1654
  36:	8b 1b                	mov    (%rbx),%ebx
  38:	bf 00 05 00 00       	mov    $0x500,%edi
  3d:	89 de                	mov    %ebx,%esi
  3f:	e8                   	.byte 0xe8

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/16 02:35 upstream ad1b832bf1cf 40a34ec9 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in add_grec
2025/02/11 12:20 upstream febbc555cf0f 43f51a00 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in add_grec
* Struck through repros no longer work on HEAD.