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general protection fault in ip6_route_output_flags (2)

Status: closed as invalid on 2025/09/12 22:39
Subsystems: net
[Documentation on labels]
First crash: 53d, last: 53d
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in ip6_route_output_flags net 2 1 2475d 2475d 0/29 auto-closed as invalid on 2019/06/18 17:02
upstream KASAN: slab-out-of-bounds Read in ip6_route_output_flags net bcachefs 17 syz 1 229d 229d 0/29 closed as invalid on 2025/03/17 11:18
upstream KMSAN: kernel-infoleak in copyout (2) net 17 C 6723 845d 2013d 22/29 fixed on 2023/06/08 14:41

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000009: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000048-0x000000000000004f]
CPU: 0 UID: 0 PID: 15 Comm: ksoftirqd/0 Not tainted 6.16.0-syzkaller-06619-gd942fe13f72b #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:ip6_route_output_flags_noref net/ipv6/route.c:2682 [inline]
RIP: 0010:ip6_route_output_flags+0x336/0x5d0 net/ipv6/route.c:2696
Code: 90 80 99 f7 83 cd 04 4c 8b 2c 24 eb 35 e8 82 80 99 f7 45 31 f6 48 bb 00 00 00 00 00 fc ff df 49 83 c6 4e 4c 89 f0 48 c1 e8 03 <0f> b6 04 18 84 c0 0f 85 27 02 00 00 41 0f b6 06 c1 e0 03 83 e0 38
RSP: 0018:ffffc900001472d8 EFLAGS: 00010207
RAX: 0000000000000009 RBX: dffffc0000000000 RCX: ffff88801d2abc00
RDX: 0000000000000100 RSI: 0000000000000080 RDI: 0000000000000000
RBP: 0000000000000081 R08: ffff88801d2abc00 R09: 0000000000000002
R10: 000000000000c0fe R11: 0000000000000100 R12: ffff888057dacb18
R13: ffff88807d5e4880 R14: 000000000000004e R15: ffffc900001475a0
FS:  0000000000000000(0000) GS:ffff888125c80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000017000 CR3: 00000000550f4000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 ip6_route_output include/net/ip6_route.h:93 [inline]
 ip6_dst_lookup_tail+0x1ae/0x1510 net/ipv6/ip6_output.c:1131
 ip6_dst_lookup_flow+0x47/0xe0 net/ipv6/ip6_output.c:1262
 tipc_udp_xmit+0x30f/0xaa0 net/tipc/udp_media.c:210
 tipc_udp_send_msg+0x27f/0x3f0 net/tipc/udp_media.c:271
 tipc_bearer_xmit_skb+0x2b0/0x400 net/tipc/bearer.c:575
 tipc_disc_timeout+0x580/0x6d0 net/tipc/discover.c:338
 call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747
 expire_timers kernel/time/timer.c:1798 [inline]
 __run_timers kernel/time/timer.c:2372 [inline]
 __run_timer_base+0x61a/0x860 kernel/time/timer.c:2384
 run_timer_base kernel/time/timer.c:2393 [inline]
 run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403
 handle_softirqs+0x283/0x870 kernel/softirq.c:579
 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:968
 smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:160
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/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:ip6_route_output_flags_noref net/ipv6/route.c:2682 [inline]
RIP: 0010:ip6_route_output_flags+0x336/0x5d0 net/ipv6/route.c:2696
Code: 90 80 99 f7 83 cd 04 4c 8b 2c 24 eb 35 e8 82 80 99 f7 45 31 f6 48 bb 00 00 00 00 00 fc ff df 49 83 c6 4e 4c 89 f0 48 c1 e8 03 <0f> b6 04 18 84 c0 0f 85 27 02 00 00 41 0f b6 06 c1 e0 03 83 e0 38
RSP: 0018:ffffc900001472d8 EFLAGS: 00010207
RAX: 0000000000000009 RBX: dffffc0000000000 RCX: ffff88801d2abc00
RDX: 0000000000000100 RSI: 0000000000000080 RDI: 0000000000000000
RBP: 0000000000000081 R08: ffff88801d2abc00 R09: 0000000000000002
R10: 000000000000c0fe R11: 0000000000000100 R12: ffff888057dacb18
R13: ffff88807d5e4880 R14: 000000000000004e R15: ffffc900001475a0
FS:  0000000000000000(0000) GS:ffff888125c80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000017000 CR3: 00000000550f4000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	90                   	nop
   1:	80 99 f7 83 cd 04 4c 	sbbb   $0x4c,0x4cd83f7(%rcx)
   8:	8b 2c 24             	mov    (%rsp),%ebp
   b:	eb 35                	jmp    0x42
   d:	e8 82 80 99 f7       	call   0xf7998094
  12:	45 31 f6             	xor    %r14d,%r14d
  15:	48 bb 00 00 00 00 00 	movabs $0xdffffc0000000000,%rbx
  1c:	fc ff df
  1f:	49 83 c6 4e          	add    $0x4e,%r14
  23:	4c 89 f0             	mov    %r14,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	0f b6 04 18          	movzbl (%rax,%rbx,1),%eax <-- trapping instruction
  2e:	84 c0                	test   %al,%al
  30:	0f 85 27 02 00 00    	jne    0x25d
  36:	41 0f b6 06          	movzbl (%r14),%eax
  3a:	c1 e0 03             	shl    $0x3,%eax
  3d:	83 e0 38             	and    $0x38,%eax

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/07 15:09 net d942fe13f72b 04cffc22 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce general protection fault in ip6_route_output_flags
* Struck through repros no longer work on HEAD.