CVE-2026-63889
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.36%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public 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.
- CVSS 3.1
- 8.1 HIGHCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- EPSS
- 0.36% probability · 29th percentile
- CISA KEV
- Not listed
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.