Bug 2568424 (CVE-2026-100082)

Summary: CVE-2026-100082 kernel: kernel: xen-blkback: Denial of Service via race condition reading I/O statistics
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's Xen block backend (xen-blkback) driver. A race condition occurs when input/output (I/O) statistics are read through the sysfs interface while a frontend device is being disconnected. Because reading the statistics is not synchronized with freeing device memory, a local user could trigger a use-after-free (UAF) or null-pointer dereference. This flaw primarily leads to a system crash resulting in a Denial of Service (DoS).
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Description OSIDB Bzimport 2026-11-06 18:31:32 UTC 
In the Linux kernel, the following vulnerability has been resolved:

xen-blkback: Avoid UAF when reading I/O statistics

Reading I/O statistics via sysfs concurrently with tearing down a
frontend device might result in UAF or a NULL dereference, as the
reading of the statistics data is not synchronized with freeing the
data.

Use a rwlock for synchronizing.

This is XSA-528 / CVE-2026-100082