---
id: CVE-2026-98095
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  af_packet: Don't cast tpacket_hdr.tp_len to int in tpacket_parse_header().

  syzbot reported BUG() in sock_sendmsg_nosec()
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  af_packet: Don't cast tpacket_hdr.tp_len to int in tpacket_parse_header().

  syzbot reported BUG() in sock_sendmsg_nosec(). [0]

  The problem is that tpacket_parse_header…
severity: medium
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1 <
    3e0cad1432a0c0564f5076bab16f1aa4c0474be4
  - >-
    Linux >= 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1 <
    6d4d55f75fa0ea32d874eb33e356e9361f3e4591
  - >-
    Linux >= 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1 <
    09e3c9b32434600a6992e762bf0d6837f5902134
  - >-
    Linux >= 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1 <
    2b9fa12fbdbfc0f671ff23b0ea06c177a6b8a6b8
  - >-
    Linux >= 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1 <
    c6b3db727876a027013aa4ccb6913a153a2af41a
  - >-
    Linux >= 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1 <
    72abe77e88c3f1f71c5348124e9b28e285f26950
  - >-
    Linux >= 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1 <
    9d714076ff398ba8cc5ae0ae146f4a1ea0bbf5e8
  - >-
    Linux >= 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1 <
    73e594c19b4f815d8343461cec7074c4713bbde7
  - Linux 2.6.31
published: '2026-09-25'
updated: '2026-10-03'
sourceUpdated: '2026-10-03T11:18:31.633'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98095'
references:
  - url: 'https://git.kernel.org/stable/c/09e3c9b32434600a6992e762bf0d6837f5902134'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/2b9fa12fbdbfc0f671ff23b0ea06c177a6b8a6b8'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/3e0cad1432a0c0564f5076bab16f1aa4c0474be4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/6d4d55f75fa0ea32d874eb33e356e9361f3e4591'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/72abe77e88c3f1f71c5348124e9b28e285f26950'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/73e594c19b4f815d8343461cec7074c4713bbde7'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9d714076ff398ba8cc5ae0ae146f4a1ea0bbf5e8'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c6b3db727876a027013aa4ccb6913a153a2af41a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98095.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-98095'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2541070'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-98095'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98095'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98095.mbox
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00123
epssPercentile: 0.02005
ingestedAt: '2026-09-25T11:06:38.830Z'
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe:
  - CWE-681
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

af_packet: Don't cast tpacket_hdr.tp_len to int in tpacket_parse_header().

syzbot reported BUG() in sock_sendmsg_nosec(). [0]

The problem is that tpacket_parse_header() casts user-provided
tpacket_hdr.tp_len, which is u32, to int.

If the length is larger than INT_MAX, the following condition
in tpacket_parse_header() passes,

  if (unlikely(tp_len > size_max))

and any negative value can be returned to the caller, up to
sock_sendmsg_nosec().

The repro set tpacket_hdr.tp_len to 0xfffffdef, which is cast
to -EIOCBQUEUED (-529), triggering BUG() in sock_sendmsg_nosec().

  *(uint64_t*)0x200000000008 = 0xfffffdef;
  ...
  syscall(__NR_write, /*fd=*/r[0], /*buf=*/0x200000000000ul, /*count=*/1ul);

Let's define the local tp_len as u32 in tpacket_parse_header().

[0]:
kernel BUG at net/socket.c:803!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 5628 Comm: syz-executor176 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:sock_sendmsg_nosec+0x145/0x180 net/socket.c:803
Code: 06 67 48 0f b9 3a eb 95 e8 e8 3a 22 f8 48 89 df 4c 89 f6 4c 89 e2 4d 89 fb 2e e8 32 a5 5c 16 e9 51 ff ff ff e8 cc 3a 22 f8 90 <0f> 0b e8 c4 3a 22 f8 48 83 c3 18 48 89 d8 48 c1 e8 03 42 80 3c 28
RSP: 0018:ffffc90003aefb48 EFLAGS: 00010293
RAX: ffffffff89a578d4 RBX: ffff8880764c67c0 RCX: ffff88807fb23e80
RDX: 0000000000000000 RSI: 00000000fffffdef RDI: 00000000fffffdef
RBP: 00000000fffffdef R08: ffffc90003aef747 R09: 1ffff9200075dee8
R10: dffffc0000000000 R11: fffff5200075dee9 R12: 0000000000000001
R13: dffffc0000000000 R14: ffffc90003aefbc0 R15: ffffffff8aac4310
FS:  000055559101b400(0000) GS:ffff888124ce0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000210 CR3: 0000000073dca000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __sock_sendmsg net/socket.c:815 [inline]
 sock_write_iter+0x2de/0x3e0 net/socket.c:1266
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x612/0xba0 fs/read_write.c:687
 ksys_write+0x150/0x270 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f173130ecb9
Code: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 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 d8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd67e44248 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000200000000000 RCX: 00007f173130ecb9
RDX: 0000000000000001 RSI: 0000200000000000 RDI: 0000000000000003
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd67e44388
R13: 0000000000000002 R14: 00002000000000c0 R15: 0000000000000002
 </TASK>

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-10-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98095.json)