[syzbot] [net?] general protection fault in ife_tlv_meta_encode

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: c03e9c42ae8f Merge tag 'dma-mapping-6.19-2026-01-20' of gi..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12ce73fa580000
kernel config: https://syzkaller.appspot.com/x/.config?x=ae589cd0a6acd9be
dashboard link: https://syzkaller.appspot.com/bug?extid=5cf914f193dffde3bd3c
compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: i386

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-c03e9c42.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b6abca6c0155/vmlinux-c03e9c42.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1bcd936b6484/bzImage-c03e9c42.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5cf914...@syzkaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 3 UID: 0 PID: 8990 Comm: syz.0.696 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:ife_tlv_meta_encode+0x41/0xa0 net/ife/ife.c:166
Code: 89 d5 53 89 f3 c1 e3 10 e8 8c ed 71 f6 0f b7 c5 4c 89 ea 44 8d 78 07 83 c0 04 48 c1 ea 03 09 c3 48 b8 00 00 00 00 00 fc ff df <0f> b6 14 02 4c 89 e8 0f cb 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75
RSP: 0018:ffffc900038cf238 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000010008 RCX: ffffc900038cf290
RDX: 0000000000000000 RSI: ffffffff8b4c7434 RDI: 0000000000000000
RBP: 0000000000000004 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000001000 R11: 000000000000001e R12: ffffc900038cf290
R13: 0000000000000000 R14: 0000000000000004 R15: 000000000000000b
FS: 0000000000000000(0000) GS:ffff8880979f6000(0063) knlGS:00000000f544db40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f544cfac CR3: 000000006a9f4000 CR4: 0000000000352ef0
Call Trace:
<TASK>
ife_encode_meta_u32+0x153/0x180 net/sched/act_ife.c:101
tcf_ife_encode net/sched/act_ife.c:841 [inline]
tcf_ife_act+0x1022/0x1de0 net/sched/act_ife.c:877
tc_act include/net/tc_wrapper.h:130 [inline]
tcf_action_exec+0x1c0/0xa20 net/sched/act_api.c:1152
tcf_exts_exec include/net/pkt_cls.h:349 [inline]
mall_classify+0x1a0/0x2a0 net/sched/cls_matchall.c:42
tc_classify include/net/tc_wrapper.h:197 [inline]
__tcf_classify net/sched/cls_api.c:1764 [inline]
tcf_classify+0x7f2/0x1380 net/sched/cls_api.c:1860
multiq_classify net/sched/sch_multiq.c:39 [inline]
multiq_enqueue+0xe0/0x510 net/sched/sch_multiq.c:66
dev_qdisc_enqueue+0x45/0x250 net/core/dev.c:4147
__dev_xmit_skb net/core/dev.c:4262 [inline]
__dev_queue_xmit+0x2998/0x46c0 net/core/dev.c:4798
dev_queue_xmit include/linux/netdevice.h:3381 [inline]
packet_xmit+0x23e/0x350 net/packet/af_packet.c:275
packet_snd net/packet/af_packet.c:3076 [inline]
packet_sendmsg+0x26e3/0x54a0 net/packet/af_packet.c:3108
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
____sys_sendmsg+0xa5d/0xc30 net/socket.c:2592
___sys_sendmsg+0x134/0x1d0 net/socket.c:2646
__sys_sendmsg+0x16d/0x220 net/socket.c:2678
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0xe8/0x680 arch/x86/entry/syscall_32.c:307
do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:332
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf705d579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f544d55c EFLAGS: 00000296 ORIG_RAX: 0000000000000172
RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00000000800000c0
RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ife_tlv_meta_encode+0x41/0xa0 net/ife/ife.c:166
Code: 89 d5 53 89 f3 c1 e3 10 e8 8c ed 71 f6 0f b7 c5 4c 89 ea 44 8d 78 07 83 c0 04 48 c1 ea 03 09 c3 48 b8 00 00 00 00 00 fc ff df <0f> b6 14 02 4c 89 e8 0f cb 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75
RSP: 0018:ffffc900038cf238 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000010008 RCX: ffffc900038cf290
RDX: 0000000000000000 RSI: ffffffff8b4c7434 RDI: 0000000000000000
RBP: 0000000000000004 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000001000 R11: 000000000000001e R12: ffffc900038cf290
R13: 0000000000000000 R14: 0000000000000004 R15: 000000000000000b
FS: 0000000000000000(0000) GS:ffff8880979f6000(0063) knlGS:00000000f544db40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f544cfac CR3: 000000006a9f4000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
0: 89 d5 mov %edx,%ebp
2: 53 push %rbx
3: 89 f3 mov %esi,%ebx
5: c1 e3 10 shl $0x10,%ebx
8: e8 8c ed 71 f6 call 0xf671ed99
d: 0f b7 c5 movzwl %bp,%eax
10: 4c 89 ea mov %r13,%rdx
13: 44 8d 78 07 lea 0x7(%rax),%r15d
17: 83 c0 04 add $0x4,%eax
1a: 48 c1 ea 03 shr $0x3,%rdx
1e: 09 c3 or %eax,%ebx
20: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
27: fc ff df
* 2a: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx <-- trapping instruction
2e: 4c 89 e8 mov %r13,%rax
31: 0f cb bswap %ebx
33: 83 e0 07 and $0x7,%eax
36: 83 c0 03 add $0x3,%eax
39: 38 d0 cmp %dl,%al
3b: 7c 04 jl 0x41
3d: 84 d2 test %dl,%dl
3f: 75 .byte 0x75


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: d8f87aa5fa0a net: remove HIPPI support and RoadRunner HIPP..
git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=11fbf852580000
kernel config: https://syzkaller.appspot.com/x/.config?x=c06d757173270a35
dashboard link: https://syzkaller.appspot.com/bug?extid=5cf914f193dffde3bd3c
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10d4a7fc580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1691f3fa580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/502d97c34968/disk-d8f87aa5.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/71a9c26032b6/vmlinux-d8f87aa5.xz
kernel image: https://storage.googleapis.com/syzbot-assets/78eeec8d5dbf/bzImage-d8f87aa5.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5cf914...@syzkaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI

KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]

CPU: 1 UID: 0 PID: 5987 Comm: syz.0.18 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
RIP: 0010:ife_tlv_meta_encode+0x46/0xb0 net/ife/ife.c:166
Code: 50 83 73 f6 45 8d 77 07 4d 8d 65 04 c1 e5 10 44 89 fb 83 c3 04 09 eb 0f cb 4c 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 75 43 41 89 5d 00 41 81 e6 fc ff 00 00 41 8d 46
RSP: 0018:ffffc90003426f60 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000008000300 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000000
RBP: 0000000000030000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff8979aa80 R12: 0000000000000004
R13: 0000000000000000 R14: 000000000000000b R15: 0000000000000004
FS: 000055557c2de500(0000) GS:ffff888125a29000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c0083cc000 CR3: 00000000763c8000 CR4: 00000000003526f0
Call Trace:
<TASK>
ife_encode_meta_u32+0x126/0x1c0 net/sched/act_ife.c:101
tcf_ife_encode net/sched/act_ife.c:841 [inline]
tcf_ife_act+0x10fd/0x1d80 net/sched/act_ife.c:877
tc_act include/net/tc_wrapper.h:130 [inline]
tcf_action_exec+0x185/0x8e0 net/sched/act_api.c:1152

tc_classify include/net/tc_wrapper.h:197 [inline]
__tcf_classify net/sched/cls_api.c:1764 [inline]

tcf_classify+0x4cf/0x1130 net/sched/cls_api.c:1860
multiq_classify net/sched/sch_multiq.c:39 [inline]
multiq_enqueue+0x102/0x4d0 net/sched/sch_multiq.c:66
dev_qdisc_enqueue+0x4e/0x240 net/core/dev.c:4146
__dev_xmit_skb net/core/dev.c:4261 [inline]
__dev_queue_xmit+0x1933/0x32b0 net/core/dev.c:4797
packet_snd net/packet/af_packet.c:3076 [inline]
packet_sendmsg+0x3eb6/0x50f0 net/packet/af_packet.c:3108
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg+0x21c/0x270 net/socket.c:742
____sys_sendmsg+0x4d7/0x810 net/socket.c:2592
___sys_sendmsg+0x2a5/0x360 net/socket.c:2646
__sys_sendmsg net/socket.c:2678 [inline]
__do_sys_sendmsg net/socket.c:2683 [inline]
__se_sys_sendmsg net/socket.c:2681 [inline]
__x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2a0039acb9
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:00007fff41bd8b88 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f2a00615fa0 RCX: 00007f2a0039acb9
RDX: 0000000000000004 RSI: 00002000000000c0 RDI: 0000000000000008
RBP: 00007fff41bd8bf0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007f2a00615fac R14: 00007f2a00615fa0 R15: 00007f2a00615fa0

</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---

RIP: 0010:ife_tlv_meta_encode+0x46/0xb0 net/ife/ife.c:166
Code: 50 83 73 f6 45 8d 77 07 4d 8d 65 04 c1 e5 10 44 89 fb 83 c3 04 09 eb 0f cb 4c 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 75 43 41 89 5d 00 41 81 e6 fc ff 00 00 41 8d 46
RSP: 0018:ffffc90003426f60 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000008000300 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000000
RBP: 0000000000030000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff8979aa80 R12: 0000000000000004
R13: 0000000000000000 R14: 000000000000000b R15: 0000000000000004
FS: 000055557c2de500(0000) GS:ffff888125a29000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c0083cc000 CR3: 00000000763c8000 CR4: 00000000003526f0

----------------
Code disassembly (best guess):

0: 50 push %rax
1: 83 73 f6 45 xorl $0x45,-0xa(%rbx)
5: 8d 77 07 lea 0x7(%rdi),%esi
8: 4d 8d 65 04 lea 0x4(%r13),%r12
c: c1 e5 10 shl $0x10,%ebp
f: 44 89 fb mov %r15d,%ebx
12: 83 c3 04 add $0x4,%ebx
15: 09 eb or %ebp,%ebx
17: 0f cb bswap %ebx
19: 4c 89 e8 mov %r13,%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: 75 43 jne 0x75
32: 41 89 5d 00 mov %ebx,0x0(%r13)
36: 41 81 e6 fc ff 00 00 and $0xfffc,%r14d
3d: 41 rex.B
3e: 8d .byte 0x8d
3f: 46 rex.RX


---
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