Bug 2540337 (CVE-2026-93283)

Summary: CVE-2026-93283 kernel: i3c: master: Fix device_register() error path
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: 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   
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A flaw was found in the Linux kernel's I3C (Improved Inter-Integrated Circuit) master subsystem. This issue can result in a Denial of Service (DoS) caused by a system crash. When device registration fails, the driver frees the device object but fails to clear internal pointers referencing the freed memory. A local user could exploit this dangling reference during subsequent device unregistration to trigger a use-after-free condition.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-09-24 16:22:10 UTC 
In the Linux kernel, the following vulnerability has been resolved:

i3c: master: Fix device_register() error path

When device_register() fails in i3c_master_register_new_i3c_devs(),
put_device() is called to drop the reference taken by
device_register().  That drops the last reference, so the device's
release callback i3c_device_release() runs and frees the i3c_device.

Two problems follow from that:

i3c_device_release() does WARN_ON(i3cdev->desc), so it warns because
desc->dev->desc still points back at the descriptor.  Clear it before
calling put_device().

After put_device() frees the i3c_device, desc->dev is left pointing at
freed memory, so clear desc->dev as well.  That prevents, for example,
i3c_master_unregister_i3c_devs() seeing desc->dev as non-NULL and
dereferencing it.
Comment 1 gkamathe 2026-09-28 13:55:04 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-93283.mbox