Bug 2536177 (CVE-2026-90337)

Summary:	CVE-2026-90337 kernel: serial: core: do fallible allocations before the console can be registered
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 serial core component. This vulnerability occurs when the system attempts to allocate resources for a serial port after the console has been registered. If this allocation fails, the driver may improperly handle the port, leading to memory corruption issues such as a NULL dereference or a use-after-free error. This can cause the system to crash, resulting in a denial of service.	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 2026-09-17 16:41:32 UTC

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

serial: core: do fallible allocations before the console can be registered

serial_core_add_one_port() allocates uport->tty_groups after
uart_configure_port(), which may register the console. If the allocation
fails, the driver unwinds the port while its console remains registered.
The earlier uport->name allocation has a related failure path that leaves
state->uart_port linked to a port being freed.

Failslab reproduced a NULL dereference in PL011 console output and a KASAN
use-after-free in i.MX console output after failed binds.

Allocate the name and tty_groups before linking the port and configuring
it. Reserve space for the optional driver attribute group because
config_port() may populate uport->attr_group during configuration.

Comment 1 gkamathe 2026-09-21 20:31:03 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-90337.mbox