Bug 2541224 (CVE-2026-98030)

Summary:	CVE-2026-98030 kernel: net: dsa: bcm_sf2: bound the CFP rule dump by the caller's buffer size
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel's Broadcom Starfighter 2 (bcm_sf2) network switch driver. An unprivileged local user can exploit this vulnerability by issuing a network control request to retrieve classification rules while providing a buffer size smaller than the number of active rules. Because the driver does not validate the user-supplied buffer limit, it can write data beyond the allocated memory or dereference a null pointer, leading to kernel memory corruption or a Denial of Service (DoS).	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-09-25 11:05:02 UTC

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

net: dsa: bcm_sf2: bound the CFP rule dump by the caller's buffer size

bcm_sf2_cfp_rule_get_all() walks the whole cfp.unique bitmap into
rule_locs[] without consulting nfc->rule_cnt, which is how many entries
the caller had room for.  ETHTOOL_GRXCLSRLALL requires no CAP_NET_ADMIN
and the ioctl sizes the buffer from the rule_cnt userspace passes in, so
once an admin has installed CFP rules any user can ask for fewer slots
than there are rules and run off the end of the allocation.  A rule_cnt
of 0 leaves the buffer pointer NULL and the walk dereferences it.

Comment 1 Keith Grant 2026-09-28 21:46:22 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98030.mbox