CVE-2026-63889

scsi: scsi_transport_fc: Widen FPIN pname walker counter to u32

HIGH
8.1
CVSS Score
Published: July 19, 2026 at 02:55 PM UTC
Updated: October 29, 2026 at 07:16 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH8.1
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: scsi: scsi_transport_fc: Widen FPIN pname walker counter to u32 An adjacent Fibre Channel fabric actor that can deliver an FPIN ELS frame to an lpfc or qla2xxx Linux initiator can trigger a non-return in the generic FC transport. This is not a local userspace or IP network path; the attacker must be able to inject fabric traffic, for example as a compromised switch or fabric controller, or as a same-zone N_Port on a fabric that permits source spoofing. The Link-Integrity and Peer-Congestion FPIN walkers used a u8 loop counter against the 32-bit on-wire pname_count field, and did not bound pname_count by the descriptor body already validated by the TLV walker. A pname_count of 256 therefore wraps the counter and keeps the loop condition true indefinitely. Factor the shared pname_list[] walk into one helper, widen the counter to u32, and clamp pname_count against the entries that fit in the descriptor body before iterating.

Affected

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

5.11 ≤ v < 5.15.2105.16 ≤ v < 6.1.1766.13 ≤ v < 6.18.356.19 ≤ v < 7.0.126.2 ≤ v < 6.6.1436.7 ≤ v < 6.12.933dcfe0de5a9752e646a61f4ce513ac059960c7c35.117.1
Vendor states this is fixed in 07776b7779c9426982c1ad74aad91bd531593790 (fixed)
Vendor states this is fixed in 163bd704d7515c3df6c2e03bcba93d1db79edbff (fixed)
Vendor states this is fixed in 29f126f09e34a425b376b3646c89aa7cc18b142c (fixed)
Vendor states this is fixed in 35461d23744175a78b6280293892cca357c22793 (fixed)
Vendor states this is fixed in a9a39233ec1fc9f97ea1340a4d09bb7ec2be5153 (fixed)
Vendor states this is fixed in bdff76dff6ec23d6fe35812fa33e5c4ce2cdb770 (fixed)
Vendor states this is fixed in ee57b89e5da9fffbe0d26647e4ff0750dacb9943 (fixed)
Vendor states this is fixed in 5.11 (unaffected)
Vendor states this is fixed in 5.15.210 (unaffected)
Vendor states this is fixed in 6.1.176 (unaffected)
Vendor states this is fixed in 6.12.93 (unaffected)
Vendor states this is fixed in 6.18.35 (unaffected)
Vendor states this is fixed in 6.6.143 (unaffected)
Vendor states this is fixed in 7.0.12 (unaffected)
Vendor states this is fixed in 7.1 (unaffected)

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

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

CVSS

8.1HIGHLinux
Vector?

Quick Info

StatusANALYZED
CWE
CWE-190CWE-835

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