In the Linux kernel, the following vulnerability has been resolved:

scsi: fcoe: Reject FIP descriptors with zero fip_dlen in CVL walker

drivers/scsi/fcoe/fcoe_ctlr.c::fcoe_ctlr_recv_clr_vlink() advanced the
descriptor cursor by an attacker-supplied fip_dlen without ever
requiring dlen >= sizeof(struct fip_desc) in the default branch. The
named descriptor cases (FIP_DT_MAC, FIP_DT_NAME, FIP_DT_VN_ID) checked
their per-type minimum lengths, but a FIP_DT_NON_CRITICAL descriptor
(fip_dtype >= 128, which the standard requires receivers to silently
ignore) skipped that check entirely.

An unauthenticated L2 peer on the FCoE control VLAN could hang
fcoe_ctlr_recv_work on an fcoe, qedf, or bnx2fc initiator indefinitely
by emitting one FIP CVL frame whose single descriptor had fip_dtype ==
FIP_DT_NON_CRITICAL and fip_dlen == 0: the cursor advanced zero bytes
per iteration and the loop condition rlen >= sizeof(*desc) stayed true
forever, blocking every subsequent FIP frame on that controller.

Tighten the outer dlen guard to also reject dlen < sizeof(struct
fip_desc), so a malformed descriptor whose length cannot even cover the
descriptor header is rejected before the switch. This is the same
lower-bound the named cases already apply and is the minimum scope that
closes the loop.

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Advisories
Source ID Title
Ubuntu USN Ubuntu USN USN-8593-1 Linux kernel vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 22 Jul 2026 19:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-20
CWE-718

Wed, 22 Jul 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-835
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate


Sun, 19 Jul 2026 15:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: scsi: fcoe: Reject FIP descriptors with zero fip_dlen in CVL walker drivers/scsi/fcoe/fcoe_ctlr.c::fcoe_ctlr_recv_clr_vlink() advanced the descriptor cursor by an attacker-supplied fip_dlen without ever requiring dlen >= sizeof(struct fip_desc) in the default branch. The named descriptor cases (FIP_DT_MAC, FIP_DT_NAME, FIP_DT_VN_ID) checked their per-type minimum lengths, but a FIP_DT_NON_CRITICAL descriptor (fip_dtype >= 128, which the standard requires receivers to silently ignore) skipped that check entirely. An unauthenticated L2 peer on the FCoE control VLAN could hang fcoe_ctlr_recv_work on an fcoe, qedf, or bnx2fc initiator indefinitely by emitting one FIP CVL frame whose single descriptor had fip_dtype == FIP_DT_NON_CRITICAL and fip_dlen == 0: the cursor advanced zero bytes per iteration and the loop condition rlen >= sizeof(*desc) stayed true forever, blocking every subsequent FIP frame on that controller. Tighten the outer dlen guard to also reject dlen < sizeof(struct fip_desc), so a malformed descriptor whose length cannot even cover the descriptor header is rejected before the switch. This is the same lower-bound the named cases already apply and is the minimum scope that closes the loop.
Title scsi: fcoe: Reject FIP descriptors with zero fip_dlen in CVL walker
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-07-19T14:55:02.195Z

Reserved: 2026-07-19T07:54:57.018Z

Link: CVE-2026-63890

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-07-19T00:00:00Z

Links: CVE-2026-63890 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-07-22T18:45:02Z

Weaknesses