syzbot


general protection fault in mld_clear_zeros

Status: closed as invalid on 2025/07/30 09:20
Subsystems: net
[Documentation on labels]
First crash: 69d, last: 69d

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc001fffe000: 0000 [#1] SMP KASAN PTI
KASAN: probably user-memory-access in range [0x00000000ffff0000-0x00000000ffff0007]
CPU: 0 UID: 0 PID: 14263 Comm: kworker/0:18 Not tainted 6.16.0-rc2-syzkaller-00159-ge0fca6f2cebf #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: mld mld_ifc_work
RIP: 0010:mld_clear_zeros+0xf2/0x430 net/ipv6/mcast.c:2087
Code: e8 b3 aa 9a f7 85 ed 0f 84 bd 00 00 00 e8 66 a6 9a f7 eb 05 e8 5f a6 9a f7 49 89 dc 49 c1 ec 03 48 b8 00 00 00 00 00 fc ff df <41> 80 3c 04 00 74 08 48 89 df e8 5f 24 fe f7 4c 8b 33 4c 8d 6b 2a
RSP: 0018:ffffc9000b7179b0 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 00000000ffff0000 RCX: ffff888025b5bc00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: 00000000000002ff R09: 160000ff01000000
R10: 00000000000002ff R11: 160000ff01000000 R12: 000000001fffe000
R13: 1ffff11004848706 R14: ffff88803443d538 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125c51000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffce9e0edd0 CR3: 00000000284a8000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 mld_send_cr net/ipv6/mcast.c:2128 [inline]
 mld_ifc_work+0x35d/0xde0 net/ipv6/mcast.c:2702
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:mld_clear_zeros+0xf2/0x430 net/ipv6/mcast.c:2087
Code: e8 b3 aa 9a f7 85 ed 0f 84 bd 00 00 00 e8 66 a6 9a f7 eb 05 e8 5f a6 9a f7 49 89 dc 49 c1 ec 03 48 b8 00 00 00 00 00 fc ff df <41> 80 3c 04 00 74 08 48 89 df e8 5f 24 fe f7 4c 8b 33 4c 8d 6b 2a
RSP: 0018:ffffc9000b7179b0 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 00000000ffff0000 RCX: ffff888025b5bc00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: 00000000000002ff R09: 160000ff01000000
R10: 00000000000002ff R11: 160000ff01000000 R12: 000000001fffe000
R13: 1ffff11004848706 R14: ffff88803443d538 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125c51000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffc9356388 CR3: 000000000df38000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	e8 b3 aa 9a f7       	call   0xf79aaab8
   5:	85 ed                	test   %ebp,%ebp
   7:	0f 84 bd 00 00 00    	je     0xca
   d:	e8 66 a6 9a f7       	call   0xf79aa678
  12:	eb 05                	jmp    0x19
  14:	e8 5f a6 9a f7       	call   0xf79aa678
  19:	49 89 dc             	mov    %rbx,%r12
  1c:	49 c1 ec 03          	shr    $0x3,%r12
  20:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  27:	fc ff df
* 2a:	41 80 3c 04 00       	cmpb   $0x0,(%r12,%rax,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	48 89 df             	mov    %rbx,%rdi
  34:	e8 5f 24 fe f7       	call   0xf7fe2498
  39:	4c 8b 33             	mov    (%rbx),%r14
  3c:	4c 8d 6b 2a          	lea    0x2a(%rbx),%r13

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/21 06:37 net e0fca6f2cebf d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce general protection fault in mld_clear_zeros
* Struck through repros no longer work on HEAD.