general protection fault in bpf_redirect

Status: closed as invalid on 2026/09/11 15:35
Subsystems: bpf net
Labels: prio:low
[Documentation on labels]
First crash: 114d, last: 100d
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
2df0f7a0 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ general protection fault in bpf_redirect 2026/06/09 13:58 2026/06/09 13:58 2026/06/09 14:35 c36c07f6
▶ ▼ Last patch testing requests (2)
Created Duration User Patch Repo Result
2026/08/27 11:37 23m retest repro upstream error job log
2026/06/18 11:19 17m retest repro upstream report log

Sample crash report:
syzkaller0: entered promiscuous mode
syzkaller0: entered allmulticast mode
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000007: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f]
CPU: 0 UID: 0 PID: 5922 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:bpf_net_ctx_get_ri include/linux/filter.h:819 [inline]
RIP: 0010:____bpf_redirect net/core/filter.c:2555 [inline]
RIP: 0010:bpf_redirect+0x5d/0x180 net/core/filter.c:2553
Code: 48 c1 ea 03 80 3c 02 00 0f 85 1c 01 00 00 48 8b 9b d8 18 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8d 73 38 4c 89 f2 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e cf 00 00 00 44 8b 6b 38 31 ff
RSP: 0018:ffffc900045473a8 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffff920006e1609
RDX: 0000000000000007 RSI: ffffffff896e7827 RDI: ffff88802a2d98d8
RBP: 00000080ffffffff R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: ffff888025f9b841 R12: ffff888025f9b7c0
R13: ffffc9000370b000 R14: 0000000000000038 R15: ffff88803634f6c0
FS:  000055557cc56500(0000) GS:ffff8880d6383000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000002280 CR3: 00000000269e2000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 bpf_prog_6338e008a91e2d10+0x23/0x29
 bpf_dispatcher_nop_func include/linux/bpf.h:1402 [inline]
 __bpf_prog_run include/linux/filter.h:722 [inline]
 bpf_prog_run include/linux/filter.h:729 [inline]
 bpf_prog_run_data_pointers include/linux/filter.h:917 [inline]
 cls_bpf_classify+0x533/0x1320 net/sched/cls_bpf.c:103
 tc_classify include/net/tc_wrapper.h:198 [inline]
 __tcf_classify net/sched/cls_api.c:1764 [inline]
 tcf_classify+0x7ef/0x1250 net/sched/cls_api.c:1860
 drr_classify net/sched/sch_drr.c:317 [inline]
 drr_enqueue+0x2f4/0xaa0 net/sched/sch_drr.c:346
 dev_qdisc_enqueue net/core/dev.c:4174 [inline]
 __dev_xmit_skb net/core/dev.c:4289 [inline]
 __dev_queue_xmit+0x2fe3/0x4950 net/core/dev.c:4831
 dev_queue_xmit include/linux/netdevice.h:3418 [inline]
 packet_xmit+0x243/0x310 net/packet/af_packet.c:276
 packet_snd net/packet/af_packet.c:3082 [inline]
 packet_sendmsg+0x319a/0x5100 net/packet/af_packet.c:3114
 sock_sendmsg_nosec net/socket.c:787 [inline]
 __sock_sendmsg net/socket.c:802 [inline]
 ____sys_sendmsg+0x9e1/0xb70 net/socket.c:2698
 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2752
 __sys_sendmsg+0x170/0x220 net/socket.c:2784
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f52a459ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdddfe5ca8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f52a4815fa0 RCX: 00007f52a459ce59
RDX: 0000000000000005 RSI: 0000200000000280 RDI: 0000000000000007
RBP: 00007f52a4632d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f52a4815fac R14: 00007f52a4815fa0 R15: 00007f52a4815fa0
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:bpf_net_ctx_get_ri include/linux/filter.h:819 [inline]
RIP: 0010:____bpf_redirect net/core/filter.c:2555 [inline]
RIP: 0010:bpf_redirect+0x5d/0x180 net/core/filter.c:2553
Code: 48 c1 ea 03 80 3c 02 00 0f 85 1c 01 00 00 48 8b 9b d8 18 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8d 73 38 4c 89 f2 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e cf 00 00 00 44 8b 6b 38 31 ff
RSP: 0018:ffffc900045473a8 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffff920006e1609
RDX: 0000000000000007 RSI: ffffffff896e7827 RDI: ffff88802a2d98d8
RBP: 00000080ffffffff R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: ffff888025f9b841 R12: ffff888025f9b7c0
R13: ffffc9000370b000 R14: 0000000000000038 R15: ffff88803634f6c0
FS:  000055557cc56500(0000) GS:ffff8880d6383000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000002280 CR3: 00000000269e2000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
   0:	48 c1 ea 03          	shr    $0x3,%rdx
   4:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   8:	0f 85 1c 01 00 00    	jne    0x12a
   e:	48 8b 9b d8 18 00 00 	mov    0x18d8(%rbx),%rbx
  15:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  1c:	fc ff df
  1f:	4c 8d 73 38          	lea    0x38(%rbx),%r14
  23:	4c 89 f2             	mov    %r14,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	0f b6 04 02          	movzbl (%rdx,%rax,1),%eax <-- trapping instruction
  2e:	84 c0                	test   %al,%al
  30:	74 08                	je     0x3a
  32:	3c 03                	cmp    $0x3,%al
  34:	0f 8e cf 00 00 00    	jle    0x109
  3a:	44 8b 6b 38          	mov    0x38(%rbx),%r13d
  3e:	31 ff                	xor    %edi,%edi

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/04 10:43 upstream ba3e43a9e601 197909be .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream general protection fault in bpf_redirect
* Struck through repros no longer work on HEAD.