Bug 2513242 (CVE-2026-68144)

Summary:	CVE-2026-68144 kernel: phonet: pep: fix use-after-free in pep_get_sb()
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
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 Phonet subsystem. When processing Phonet packets, a use-after-free vulnerability exists in the `pep_get_sb()` function. This occurs because the function does not correctly handle situations where packet data might be relocated in memory, leading to the use of an outdated memory address. A local attacker could exploit this to cause a system crash (denial of service) or potentially execute arbitrary code, leading to a compromise of the system.	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 2026-08-10 12:26:40 UTC

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

phonet: pep: fix use-after-free in pep_get_sb()

pep_get_sb() doesn't consider that pskb_may_pull() might have relocated
the skb data, and continue to access the older pointer, causing UAF.

Reproduced under KASAN:

  BUG: KASAN: slab-use-after-free in pep_get_sb+0x234/0x3b0
  Read of size 1 at addr ff11000105510f50 by task repro/157
   pep_get_sb+0x234/0x3b0
   pipe_handler_do_rcv+0x5f7/0xa10
   pep_do_rcv+0x203/0x410
   __sk_receive_skb+0x471/0x4a0
   phonet_rcv+0x5b3/0x6c0
   __netif_receive_skb+0xcc/0x1d0

Refetch the header with skb_header_pointer() after pskb_may_pull(), so
the possibly stale pointer is no longer dereferenced. There are better
ways to solve this, but, this is the less instrusive one.

Comment 6 Mauro Matteo Cascella 2026-08-21 20:52:08 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081000-CVE-2026-68144-39ce@gregkh/T