Bug 2532222 (CVE-2026-89617)

Summary: CVE-2026-89617 kernel: fs/ntfs3: validate dirty page table on log replay
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   
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A flaw was found in the Linux kernel's NTFS3 filesystem driver. An attacker with local access could craft a malicious NTFS log file. During log replay, insufficient validation of the `lcns_follow` field in a `DIR_PAGE_ENTRY` could lead to an out-of-bounds write. This memory corruption could result in a system crash (denial of service) or potentially allow for further exploitation.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-09-11 21:29:01 UTC 
In the Linux kernel, the following vulnerability has been resolved:

fs/ntfs3: validate dirty page table on log replay

Each DIR_PAGE_ENTRY ends in a page_lcns[] array whose length is the on-disk
lcns_follow field. check_rstbl() validates the table bookkeeping but never
checks that this array fits in the entry, so a crafted lcns_follow lets the
v0->v1 conversion memmove and later replay passes run off the entry.

Add check_dp_table() to reject, right after check_rstbl(), any entry larger
than its size claims via struct_size() (the same expression used to allocate
these entries, so the check is overflow-safe by construction). All consumers
can then trust lcns_follow as the real capacity. This covers every
page_lcns[] access whose index is bounded by the entry itself (the
conversion memmove, the HotFix store via find_dp(), and the self-bounded
scan loops). Accesses whose index comes from the log record need a separate
bound and are handled in a follow-up patch.
Comment 1 Keith Grant 2026-09-18 19:16:24 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89617.mbox