syzbot


general protection fault in ip6_mc_clear_src (2)

Status: moderation: reported on 2025/05/04 19:12
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+e8fb9e2a2bb38854b79e@syzkaller.appspotmail.com
First crash: 1d05h, last: 1d05h
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in ip6_mc_clear_src net 2 39d 49d 0/28 closed as invalid on 2025/04/18 16:40

Sample crash report:
batman_adv: batadv0: Removing interface: batadv_slave_1
veth1_macvtap: left promiscuous mode
veth0_macvtap: left promiscuous mode
veth1_vlan: left promiscuous mode
veth0_vlan: left promiscuous mode
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: 1 UID: 0 PID: 13 Comm: kworker/u8:1 Not tainted 6.15.0-rc4-syzkaller-00147-gebd297a2affa #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025
Workqueue: netns cleanup_net
RIP: 0010:ip6_mc_clear_src+0x119/0x4e0 net/ipv6/mcast.c:2599
Code: ff ff ff e8 29 ab 40 01 89 c5 31 ff 89 c6 e8 4e 85 aa f7 85 ed 74 45 e8 05 81 aa f7 eb 05 e8 fe 80 aa f7 4c 89 e0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 e7 e8 e8 75 0c f8 49 8b 2c 24 49 8d 7c
RSP: 0018:ffffc90000127198 EFLAGS: 00010206
RAX: 000000001fffe000 RBX: 1ffff11005278102 RCX: ffff88801bee0000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffffffff8f7ed377 R09: 1ffffffff1efda6e
R10: dffffc0000000000 R11: fffffbfff1efda6f R12: 00000000ffff0000
R13: dffffc0000000000 R14: 0000000000000538 R15: ffff8880293c0810
FS:  0000000000000000(0000) GS:ffff8881261cc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb0500e7d60 CR3: 000000000dd36000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __ipv6_dev_mc_dec+0x30d/0x390 net/ipv6/mcast.c:1021
 addrconf_leave_solict net/ipv6/addrconf.c:2254 [inline]
 __ipv6_ifa_notify+0x43d/0xac0 net/ipv6/addrconf.c:6299
 addrconf_ifdown+0xe69/0x1880 net/ipv6/addrconf.c:3978
 addrconf_notify+0x1bc/0x1010 net/ipv6/addrconf.c:-1
 notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2214 [inline]
 call_netdevice_notifiers net/core/dev.c:2228 [inline]
 dev_close_many+0x29c/0x410 net/core/dev.c:1731
 unregister_netdevice_many_notify+0x834/0x2330 net/core/dev.c:11952
 unregister_netdevice_many net/core/dev.c:12046 [inline]
 default_device_exit_batch+0x819/0x890 net/core/dev.c:12538
 ops_exit_list net/core/net_namespace.c:177 [inline]
 cleanup_net+0x7a9/0xbd0 net/core/net_namespace.c:654
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ip6_mc_clear_src+0x119/0x4e0 net/ipv6/mcast.c:2599
Code: ff ff ff e8 29 ab 40 01 89 c5 31 ff 89 c6 e8 4e 85 aa f7 85 ed 74 45 e8 05 81 aa f7 eb 05 e8 fe 80 aa f7 4c 89 e0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 e7 e8 e8 75 0c f8 49 8b 2c 24 49 8d 7c
RSP: 0018:ffffc90000127198 EFLAGS: 00010206
RAX: 000000001fffe000 RBX: 1ffff11005278102 RCX: ffff88801bee0000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffffffff8f7ed377 R09: 1ffffffff1efda6e
R10: dffffc0000000000 R11: fffffbfff1efda6f R12: 00000000ffff0000
R13: dffffc0000000000 R14: 0000000000000538 R15: ffff8880293c0810
FS:  0000000000000000(0000) GS:ffff8881261cc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055cc4ad91f50 CR3: 000000007b2a6000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess), 3 bytes skipped:
   0:	e8 29 ab 40 01       	call   0x140ab2e
   5:	89 c5                	mov    %eax,%ebp
   7:	31 ff                	xor    %edi,%edi
   9:	89 c6                	mov    %eax,%esi
   b:	e8 4e 85 aa f7       	call   0xf7aa855e
  10:	85 ed                	test   %ebp,%ebp
  12:	74 45                	je     0x59
  14:	e8 05 81 aa f7       	call   0xf7aa811e
  19:	eb 05                	jmp    0x20
  1b:	e8 fe 80 aa f7       	call   0xf7aa811e
  20:	4c 89 e0             	mov    %r12,%rax
  23:	48 c1 e8 03          	shr    $0x3,%rax
* 27:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1) <-- trapping instruction
  2c:	74 08                	je     0x36
  2e:	4c 89 e7             	mov    %r12,%rdi
  31:	e8 e8 75 0c f8       	call   0xf80c761e
  36:	49 8b 2c 24          	mov    (%r12),%rbp
  3a:	49                   	rex.WB
  3b:	8d                   	.byte 0x8d
  3c:	7c                   	.byte 0x7c

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/05/04 17:01 net ebd297a2affa b0714e37 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce general protection fault in ip6_mc_clear_src
* Struck through repros no longer work on HEAD.