Bug 2532294 (CVE-2026-89636)

Summary: CVE-2026-89636 kernel: smb: client: clear ce->tgthint in free_tgts()
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   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the Linux kernel's Server Message Block (SMB) client. When the `free_tgts()` function frees data structures, a pointer (`ce->tgthint`) is not properly reset, leaving it pointing to a memory location that has already been deallocated. If this pointer is subsequently used, it can lead to a use-after-free vulnerability. This could potentially allow a local attacker to cause a denial of service or escalate privileges.
 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 22:11:07 UTC 
In the Linux kernel, the following vulnerability has been resolved:

smb: client: clear ce->tgthint in free_tgts()

When free_tgts() frees all structures in ce->tlist, ce->tgthint
is left pointing to one of the freed cache_dfs_tgt structures.

If ce->tgthint is not reset before it is used later, it results
in a use-after-free.

Set ce->tgthint to NULL in free_tgts() after the elements are
freed to reflect that no elements remain.
Comment 1 Keith Grant 2026-09-18 20:14:29 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89636.mbox