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

sctp: linearize cloned gso packets in sctp_rcv

A cloned head skb still shares these frag skbs in fraglist with the
original head skb. It's not safe to access these frag skbs.

syzbot reported two use-of-uninitialized-memory bugs caused by this:

BUG: KMSAN: uninit-value in sctp_inq_pop+0x15b7/0x1920 net/sctp/inqueue.c:211
sctp_inq_pop+0x15b7/0x1920 net/sctp/inqueue.c:211
sctp_assoc_bh_rcv+0x1a7/0xc50 net/sctp/associola.c:998
sctp_inq_push+0x2ef/0x380 net/sctp/inqueue.c:88
sctp_backlog_rcv+0x397/0xdb0 net/sctp/input.c:331
sk_backlog_rcv+0x13b/0x420 include/net/sock.h:1122
__release_sock+0x1da/0x330 net/core/sock.c:3106
release_sock+0x6b/0x250 net/core/sock.c:3660
sctp_wait_for_connect+0x487/0x820 net/sctp/socket.c:9360
sctp_sendmsg_to_asoc+0x1ec1/0x1f00 net/sctp/socket.c:1885
sctp_sendmsg+0x32b9/0x4a80 net/sctp/socket.c:2031
inet_sendmsg+0x25a/0x280 net/ipv4/af_inet.c:851
sock_sendmsg_nosec net/socket.c:718 [inline]

and

BUG: KMSAN: uninit-value in sctp_assoc_bh_rcv+0x34e/0xbc0 net/sctp/associola.c:987
sctp_assoc_bh_rcv+0x34e/0xbc0 net/sctp/associola.c:987
sctp_inq_push+0x2a3/0x350 net/sctp/inqueue.c:88
sctp_backlog_rcv+0x3c7/0xda0 net/sctp/input.c:331
sk_backlog_rcv+0x142/0x420 include/net/sock.h:1148
__release_sock+0x1d3/0x330 net/core/sock.c:3213
release_sock+0x6b/0x270 net/core/sock.c:3767
sctp_wait_for_connect+0x458/0x820 net/sctp/socket.c:9367
sctp_sendmsg_to_asoc+0x223a/0x2260 net/sctp/socket.c:1886
sctp_sendmsg+0x3910/0x49f0 net/sctp/socket.c:2032
inet_sendmsg+0x269/0x2a0 net/ipv4/af_inet.c:851
sock_sendmsg_nosec net/socket.c:712 [inline]

This patch fixes it by linearizing cloned gso packets in sctp_rcv().

Metrics

No CVSS v4.0

Attack Vector Local

Attack Complexity High

Privileges Required Low

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00032.

Key SSVC decision points have not yet been added.

Affected Vendors & Products

Vendors Products
Linux
  • Linux Kernel

No data.

No data.

OpenCVE Enrichment is a feature of OpenCVE that uses AI to automatically link vendors and products to CVEs. Learn more on GitHub.

Vendors Products
Linux
  • Linux Kernel
Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://git.kernel.org/stable/c/03d0cc6889e02420125510b5444b570f4bbf53d5 cve-icon cve-icon
https://git.kernel.org/stable/c/1bd5214ea681584c5886fea3ba03e49f93a43c0e cve-icon cve-icon
https://git.kernel.org/stable/c/7d757f17bc2ef2727994ffa6d5d6e4bc4789a770 cve-icon cve-icon
https://git.kernel.org/stable/c/cd0e92bb2b7542fb96397ffac639b4f5b099d0cb cve-icon cve-icon
https://git.kernel.org/stable/c/d0194e391bb493aa6cec56d177b14df6b29188d5 cve-icon cve-icon
https://git.kernel.org/stable/c/ea094f38d387d1b0ded5dee4a3e5720aa4ce0139 cve-icon cve-icon
https://git.kernel.org/stable/c/fc66772607101bd2030a4332b3bd0ea3b3605250 cve-icon cve-icon
https://git.kernel.org/stable/c/fd60d8a086191fe33c2d719732d2482052fa6805 cve-icon cve-icon
https://lore.kernel.org/linux-cve-announce/2025090459-CVE-2025-38718-5bb6@gregkh/T cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2025-38718 cve-icon
https://www.cve.org/CVERecord?id=CVE-2025-38718 cve-icon
History

Fri, 05 Sep 2025 14:15:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Vendors & Products Linux
Linux linux Kernel

Fri, 05 Sep 2025 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

 cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Important

Thu, 04 Sep 2025 15:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: sctp: linearize cloned gso packets in sctp_rcv A cloned head skb still shares these frag skbs in fraglist with the original head skb. It's not safe to access these frag skbs. syzbot reported two use-of-uninitialized-memory bugs caused by this: BUG: KMSAN: uninit-value in sctp_inq_pop+0x15b7/0x1920 net/sctp/inqueue.c:211 sctp_inq_pop+0x15b7/0x1920 net/sctp/inqueue.c:211 sctp_assoc_bh_rcv+0x1a7/0xc50 net/sctp/associola.c:998 sctp_inq_push+0x2ef/0x380 net/sctp/inqueue.c:88 sctp_backlog_rcv+0x397/0xdb0 net/sctp/input.c:331 sk_backlog_rcv+0x13b/0x420 include/net/sock.h:1122 __release_sock+0x1da/0x330 net/core/sock.c:3106 release_sock+0x6b/0x250 net/core/sock.c:3660 sctp_wait_for_connect+0x487/0x820 net/sctp/socket.c:9360 sctp_sendmsg_to_asoc+0x1ec1/0x1f00 net/sctp/socket.c:1885 sctp_sendmsg+0x32b9/0x4a80 net/sctp/socket.c:2031 inet_sendmsg+0x25a/0x280 net/ipv4/af_inet.c:851 sock_sendmsg_nosec net/socket.c:718 [inline] and BUG: KMSAN: uninit-value in sctp_assoc_bh_rcv+0x34e/0xbc0 net/sctp/associola.c:987 sctp_assoc_bh_rcv+0x34e/0xbc0 net/sctp/associola.c:987 sctp_inq_push+0x2a3/0x350 net/sctp/inqueue.c:88 sctp_backlog_rcv+0x3c7/0xda0 net/sctp/input.c:331 sk_backlog_rcv+0x142/0x420 include/net/sock.h:1148 __release_sock+0x1d3/0x330 net/core/sock.c:3213 release_sock+0x6b/0x270 net/core/sock.c:3767 sctp_wait_for_connect+0x458/0x820 net/sctp/socket.c:9367 sctp_sendmsg_to_asoc+0x223a/0x2260 net/sctp/socket.c:1886 sctp_sendmsg+0x3910/0x49f0 net/sctp/socket.c:2032 inet_sendmsg+0x269/0x2a0 net/ipv4/af_inet.c:851 sock_sendmsg_nosec net/socket.c:712 [inline] This patch fixes it by linearizing cloned gso packets in sctp_rcv().
Title sctp: linearize cloned gso packets in sctp_rcv
References
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-09-29T05:56:42.147Z

Reserved: 2025-04-16T04:51:24.033Z

Link: CVE-2025-38718

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-09-04T16:15:41.413

Modified: 2025-09-05T17:47:24.833

Link: CVE-2025-38718

cve-icon Redhat

Severity : Important

Publid Date: 2025-09-04T00:00:00Z

Links: CVE-2025-38718 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2025-09-05T14:02:35Z