Bug 2481969 (CVE-2026-46045)

Summary: CVE-2026-46045 kernel: md/md-llbitmap: skip reading rdevs that are not in_sync
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: 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, specifically within the multiple device (MD) driver's bitmap handling. This vulnerability allows the system to read outdated or incomplete data from storage devices that are not fully synchronized. This can lead to errors in tracking changes to data, which may result in data corruption during system recovery or regular operations.
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Description OSIDB Bzimport 2026-05-27 15:04:51 UTC 
In the Linux kernel, the following vulnerability has been resolved:

md/md-llbitmap: skip reading rdevs that are not in_sync

When reading bitmap pages from member disks, the code iterates through
all rdevs and attempts to read from the first available one. However,
it only checks for raid_disk assignment and Faulty flag, missing the
In_sync flag check.

This can cause bitmap data to be read from spare disks that are still
being rebuilt and don't have valid bitmap information yet. Reading
stale or uninitialized bitmap data from such disks can lead to
incorrect dirty bit tracking, potentially causing data corruption
during recovery or normal operation.

Add the In_sync flag check to ensure bitmap pages are only read from
fully synchronized member disks that have valid bitmap data.
Comment 1 Keith Grant 2026-05-27 19:26:33 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026052752-CVE-2026-46045-ce33@gregkh/T