mptcp: fix NULL pointer in can_accept_new_subflow

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2025-23145
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2025-05-01 13:15:50 UTC
Updated2026-07-30 06:22:16 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: mptcp: fix NULL pointer in can_accept_new_subflow When testing valkey benchmark tool with MPTCP, the kernel panics in 'mptcp_can_accept_new_subflow' because subflow_req->msk is NULL. Call trace: mptcp_can_accept_new_subflow (./net/mptcp/subflow.c:63 (discriminator 4)) (P) subflow_syn_recv_sock (./net/mptcp/subflow.c:854) tcp_check_req (./net/ipv4/tcp_minisocks.c:863) tcp_v4_rcv (./net/ipv4/tcp_ipv4.c:2268) ip_protocol_deliver_rcu (./net/ipv4/ip_input.c:207) ip_local_deliver_finish (./net/ipv4/ip_input.c:234) ip_local_deliver (./net/ipv4/ip_input.c:254) ip_rcv_finish (./net/ipv4/ip_input.c:449) ... According to the debug log, the same req received two SYN-ACK in a very short time, very likely because the client retransmits the syn ack due to multiple reasons. Even if the packets are transmitted with a relevant time interval, they can be processed by the server on different CPUs concurrently). The 'subflow_req->msk' ownership is transferred to the subflow the first, and there will be a risk of a null pointer dereference here. This patch fixes this issue by moving the 'subflow_req->msk' under the `own_req == true` conditional. Note that the !msk check in subflow_hmac_valid() can be dropped, because the same check already exists under the own_req mpj branch where the code has been moved to.

Risk And Classification

Primary CVSS: v3.1 5.5 MEDIUM from [email protected]

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Problem Types: CWE-476

VersionSourceTypeScoreSeverityVector
3.1[email protected]Primary5.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
3.1416baaa9-dc9f-4396-8d5f-8c081fb06d67Secondary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
3.1CNADECLARED7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Linux Linux Kernel All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 9466a1ccebbe54ac57fb8a89c2b4b854826546a8 8cf7fef1bb2ffea7792bcbf71ca00216cecc725d git Not specified
CNA Linux Linux affected 9466a1ccebbe54ac57fb8a89c2b4b854826546a8 b3088bd2a6790c8efff139d86d7a9d0b1305977b git Not specified
CNA Linux Linux affected 9466a1ccebbe54ac57fb8a89c2b4b854826546a8 855bf0aacd51fced11ea9aa0d5101ee0febaeadb git Not specified
CNA Linux Linux affected 9466a1ccebbe54ac57fb8a89c2b4b854826546a8 7f9ae060ed64aef8f174c5f1ea513825b1be9af1 git Not specified
CNA Linux Linux affected 9466a1ccebbe54ac57fb8a89c2b4b854826546a8 dc81e41a307df523072186b241fa8244fecd7803 git Not specified
CNA Linux Linux affected 9466a1ccebbe54ac57fb8a89c2b4b854826546a8 efd58a8dd9e7a709a90ee486a4247c923d27296f git Not specified
CNA Linux Linux affected 9466a1ccebbe54ac57fb8a89c2b4b854826546a8 4b2649b9717678aeb097893cc49f59311a1ecab0 git Not specified
CNA Linux Linux affected 9466a1ccebbe54ac57fb8a89c2b4b854826546a8 443041deb5ef6a1289a99ed95015ec7442f141dc git Not specified
CNA Linux Linux affected 5.9 Not specified
CNA Linux Linux unaffected 5.9 semver Not specified
CNA Linux Linux unaffected 5.10.237 5.10.* semver Not specified
CNA Linux Linux unaffected 5.15.181 5.15.* semver Not specified
CNA Linux Linux unaffected 6.1.135 6.1.* semver Not specified
CNA Linux Linux unaffected 6.6.88 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.24 6.12.* semver Not specified
CNA Linux Linux unaffected 6.13.12 6.13.* semver Not specified
CNA Linux Linux unaffected 6.14.3 6.14.* semver Not specified
CNA Linux Linux unaffected 6.15 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
lists.debian.org/debian-lts-announce/2025/05/msg00030.html af854a3a-2127-422b-91ae-364da2661108 lists.debian.org Mailing List
git.kernel.org/stable/c/8cf7fef1bb2ffea7792bcbf71ca00216cecc725d 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/7f9ae060ed64aef8f174c5f1ea513825b1be9af1 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/b3088bd2a6790c8efff139d86d7a9d0b1305977b 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/855bf0aacd51fced11ea9aa0d5101ee0febaeadb 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/efd58a8dd9e7a709a90ee486a4247c923d27296f 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/443041deb5ef6a1289a99ed95015ec7442f141dc 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
lists.debian.org/debian-lts-announce/2025/05/msg00045.html af854a3a-2127-422b-91ae-364da2661108 lists.debian.org Mailing List
git.kernel.org/stable/c/4b2649b9717678aeb097893cc49f59311a1ecab0 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/dc81e41a307df523072186b241fa8244fecd7803 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
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