Bug 2532457 (CVE-2026-80999)

Summary:	CVE-2026-80999 kernel: net: dsa: realtek: use gpiod_set_value_cansleep for reset GPIO
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
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 Realtek Digital Subscriber Line (DSA) driver. The driver incorrectly uses gpiod_set_value() instead of gpiod_set_value_cansleep() for reset GPIO operations. This can lead to system warnings when the reset GPIO is managed by a sleeping controller, potentially causing unexpected behavior or instability during the probe path.	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 2026-09-11 23:20:41 UTC

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

net: dsa: realtek: use gpiod_set_value_cansleep for reset GPIO

rtl83xx_reset_assert() and rtl83xx_reset_deassert() are only called from
the probe path, which may sleep and is not timing-critical.  When the
reset GPIO is provided by a sleeping controller such as an I2C I/O
expander, gpiod_set_value() warns:

  WARNING: drivers/gpio/gpiolib.c:4030 at gpiod_set_value+0x44/0x80, CPU#1: kworker/u16:4/61
  Hardware name: B&O MAP CA33 Rev f (UNKNOWN) (DT)
  Workqueue: events_unbound deferred_probe_work_func
  pc : gpiod_set_value+0x44/0x80
  lr : rtl83xx_probe+0x1d8/0x3a0
  Call trace:
   gpiod_set_value+0x44/0x80 (P)
   rtl83xx_probe+0x1d8/0x3a0
   realtek_mdio_probe+0x24/0xa0
   mdio_probe+0x38/0x78
   really_probe+0xc4/0x3e0
   __driver_probe_device+0x15c/0x1b8
   driver_probe_device+0xb4/0x120
   __device_attach_driver+0xb8/0x1a0
   bus_for_each_drv+0x88/0xf0
   __device_attach+0xa0/0x1d8
   device_initial_probe+0x54/0x68
   bus_probe_device+0x38/0xa0
   deferred_probe_work_func+0xb8/0x120
   process_one_work+0x184/0x4e8
   worker_thread+0x188/0x308
   kthread+0x130/0x150
   ret_from_fork+0x10/0x20

Switch both helpers to gpiod_set_value_cansleep() so such a reset GPIO can
be used without triggering the warning.

The reset GPIO has been driven with the non-sleeping gpiod_set_value()
since the driver was added in v4.19.  The call has since been refactored
across several files - from realtek-smi.c / realtek-mdio.c into the common
rtl83xx.c module and then into the rtl83xx_reset_assert() and
rtl83xx_reset_deassert() helpers (both in v6.9).  This patch therefore
applies as-is only to kernels that carry those helpers (v6.9+); older
stable kernels need the same gpiod_set_value_cansleep() conversion at the
corresponding open-coded call sites.

Comment 1 Keith Grant 2026-09-14 20:13:13 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-80999.mbox