CVE-2026-64207

net/sched: dualpi2: fix GSO backlog accounting

MEDIUM
5.5
CVSS Score
Published: July 20, 2026 at 04:27 PM UTC
Updated: August 17, 2026 at 05:17 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.2%

Description

In the Linux kernel, the following vulnerability has been resolved: net/sched: dualpi2: fix GSO backlog accounting When DualPI2 splits a GSO skb into N segments, it propagates N additional packets to its parent before returning NET_XMIT_SUCCESS. The parent then accounts for the original skb once more, leaving its qlen one larger than the number of packets actually queued. With QFQ as the parent, after all real packets are dequeued, QFQ still has a non-zero qlen while its in-service aggregate has no active classes. qfq_choose_next_agg() returns NULL and qfq_dequeue() passes the result to qfq_peek_skb(), causing a NULL pointer dereference. Follow the same pattern used by tbf_segment() and taprio: count only successfully queued segments, propagate the difference between the original skb and those segments, and return NET_XMIT_SUCCESS whenever at least one segment was queued.

Affected

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

6.17 ≤ v < 6.18.396.17 ≤ v < 7.1.46.17 ≤ v < 7.26.19 ≤ v < 7.1.46.178f9516daedd67097a0c6e463fcb7a42b5ee9d477
Vendor states this is fixed in 05ed733b65ab977dd931e7f7ac0f62fdb81205c2 (fixed)
Vendor states this is fixed in 806586e33891066487db1f002be3d455cda6b516 (fixed)
Vendor states this is fixed in c4b70c1512b8f9f33f23c2c8196dfd1210207681 (fixed)
Vendor states this is fixed in 6.17 (unaffected)
Vendor states this is fixed in 6.18.39 (unaffected)
Vendor states this is fixed in 7.1.4 (unaffected)
Vendor states this is fixed in 7.2 (unaffected)

CVSS

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

Quick Info

StatusANALYZED
CWE
CWE-476

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