Bug 2536714 (CVE-2026-93200)

Summary: CVE-2026-93200 kernel: i3c: master: Fix use-after-free of master->this
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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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Doc Text:
A flaw was found in the Linux kernel's i3c master driver. This use-after-free vulnerability occurs because sysfs attribute callbacks can attempt to access memory that has already been deallocated. An attacker could potentially exploit this to cause system instability or a denial of service.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-09-17 19:15:33 UTC 
In the Linux kernel, the following vulnerability has been resolved:

i3c: master: Fix use-after-free of master->this

sysfs attribute callbacks for the master controller device dereference
master->this.  However, master->this is freed in
i3c_master_detach_free_devs() before the master device itself is
released.

As a result, sysfs accesses can dereference a freed master->this
pointer, leading to a use-after-free.

Keep master->this alive until i3c_masterdev_release(), which is called
after the master device and its sysfs state are being torn down. Do not
free master->this as part of the normal device detach path.

On the error path in i3c_master_set_info(), reset master->this and
bus.cur_master to NULL before freeing the allocated device.
Comment 1 gkamathe 2026-09-18 09:59:32 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-93200.mbox