CVE-2024-26752

l2tp: pass correct message length to ip6_append_data

Published Apr 3, 2024 CVSS 3.1 · 5.5 Medium EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

l2tp: pass correct message length to ip6_append_data

l2tp_ip6_sendmsg needs to avoid accounting for the transport header
twice when splicing more data into an already partially-occupied skbuff.

To manage this, we check whether the skbuff contains data using
skb_queue_empty when deciding how much data to append using
ip6_append_data.

However, the code which performed the calculation was incorrect:

ulen = len + skb_queue_empty(&sk->sk_write_queue) ? transhdrlen : 0;

...due to C operator precedence, this ends up setting ulen to
transhdrlen for messages with a non-zero length, which results in
corrupted packets on the wire.

Add parentheses to correct the calculation in line with the original
intent.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-3840-1 linux security update
Debian DLA Debian DLA DLA-3842-1 linux-5.10 security update
Debian DSA Debian DSA DSA-5658-1 linux security update
Debian DSA Debian DSA DSA-5681-1 linux security update
Ubuntu USN Ubuntu USN USN-6820-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6820-2 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-6821-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6821-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6821-3 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-6821-4 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-6828-1 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-6831-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-6871-1 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-6892-1 Linux kernel (IBM) vulnerabilities
Ubuntu USN Ubuntu USN USN-6919-1 Linux kernel vulnerabilities
History
Type Values Removed Values Added
First Time appeared Debian
Debian debian Linux
Linux
Linux linux Kernel
Weaknesses CWE-131
CPEs cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:4.14.327:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.5.7:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc5:*:*:*:*:*:*
Vendors & Products Debian
Debian debian Linux
Linux
Linux linux Kernel
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
May 23, 2026, 3:37 PM
Reserved
Feb 19, 2024, 2:20 PM
Status
Analyzed
Published
Apr 3, 2024, 5:15 PM
Modified
Jun 17, 2026, 7:18 AM
Severity
Moderate
Public date
Apr 3, 2024, 12:00 AM