CVE-2024-40931

mptcp: ensure snd_una is properly initialized on connect

MEDIUM
5.5
CVSS Score
Published: July 12, 2024 at 12:25 PM UTC
Updated: June 17, 2026 at 07:46 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: mptcp: ensure snd_una is properly initialized on connect This is strictly related to commit fb7a0d334894 ("mptcp: ensure snd_nxt is properly initialized on connect"). It turns out that syzkaller can trigger the retransmit after fallback and before processing any other incoming packet - so that snd_una is still left uninitialized. Address the issue explicitly initializing snd_una together with snd_nxt and write_seq.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

5.11 ≤ v < 5.15.1625.16 ≤ v < 6.1.955.9 ≤ v < 5.10.2215.9 ≤ v < 5.15.1625.9 ≤ v < 6.1.955.9 ≤ v < 6.105.9 ≤ v < 6.6.355.9 ≤ v < 6.9.66.2 ≤ v < 6.6.356.7 ≤ v < 6.9.66.10 rc16.10 rc26.10 rc38fd738049ac3d67a937d36577763b47180aae1ad
Vendor states this is fixed in 208cd22ef5e57f82d38ec11c1a1703f9401d6dde (fixed)
Vendor states this is fixed in 7b9c7fc8600b64a86e4b47b2d190bba380267726 (fixed)
Vendor states this is fixed in 8031b58c3a9b1db3ef68b3bd749fbee2e1e1aaa3 (fixed)
Vendor states this is fixed in ef473bf1dd7e8dd08bcc04b9e2d1bfed69a0a7ce (fixed)
Vendor states this is fixed in f03c46eabb3a67bd2993e237ab5517f00a5f1813 (fixed)
Vendor states this is fixed in f1f0a46f8bb8890b90ab7194f0a0c8fe2a3fb57f (fixed)
Vendor states this is fixed in 5.10.221 (unaffected)
Vendor states this is fixed in 5.15.162 (unaffected)
Vendor states this is fixed in 5.9 (unaffected)
Vendor states this is fixed in 6.1.95 (unaffected)
Vendor states this is fixed in 6.10 (unaffected)
Vendor states this is fixed in 6.6.35 (unaffected)
Vendor states this is fixed in 6.9.6 (unaffected)

References (7)

Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/208cd22ef5e57f82d38ec11c1a1703f9401d6dde
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/7b9c7fc8600b64a86e4b47b2d190bba380267726
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/8031b58c3a9b1db3ef68b3bd749fbee2e1e1aaa3
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/ef473bf1dd7e8dd08bcc04b9e2d1bfed69a0a7ce
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/f03c46eabb3a67bd2993e237ab5517f00a5f1813
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/f1f0a46f8bb8890b90ab7194f0a0c8fe2a3fb57f
Source: af854a3a-2127-422b-91ae-364da2661108
https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-908

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