Bug 2507216 (CVE-2026-64386)

Summary: CVE-2026-64386 kernel: smb: client: fix query_info() replay double-free
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's Server Message Block (SMB) client. This vulnerability, a double-free error, occurs when the `query_info()` replay mechanism attempts to free a response buffer that has already been released. This can happen if an error occurs during the initialization of an SMB2 query before the next data send, leading to the same memory being freed twice. Such an issue can result in memory corruption, potentially causing a denial of service (DoS) condition for the system.
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Description OSIDB Bzimport 2026-07-25 10:11:08 UTC 
In the Linux kernel, the following vulnerability has been resolved:

smb: client: fix query_info() replay double-free

A response-bearing attempt can return a replayable error and free its
response buffer. If SMB2_query_info_init() fails before the next send,
cleanup retains the previous buffer type and frees that response again.

Reset response bookkeeping before each attempt to prevent the stale free.
Comment 1 Mauro Matteo Cascella 2026-08-02 13:25:55 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026072526-CVE-2026-64386-9e73@gregkh/T
Comment 5 errata-xmlrpc 2026-08-20 05:13:34 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:57252 https://access.redhat.com/errata/RHSA-2026:57252
Comment 6 errata-xmlrpc 2026-08-20 05:22:36 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:57251 https://access.redhat.com/errata/RHSA-2026:57251