CVE-2026-63889

Published: July 22, 2026Last modified: July 22, 2026

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.

Severity score breakdown

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References

• https://git.kernel.org/stable/c/07776b7779c9426982c1ad74aad91bd531593790
• https://git.kernel.org/stable/c/163bd704d7515c3df6c2e03bcba93d1db79edbff
• https://git.kernel.org/stable/c/29f126f09e34a425b376b3646c89aa7cc18b142c
• https://git.kernel.org/stable/c/35461d23744175a78b6280293892cca357c22793
• https://git.kernel.org/stable/c/a9a39233ec1fc9f97ea1340a4d09bb7ec2be5153
• https://git.kernel.org/stable/c/bdff76dff6ec23d6fe35812fa33e5c4ce2cdb770
• https://git.kernel.org/stable/c/ee57b89e5da9fffbe0d26647e4ff0750dacb9943