Bug 2532494 (CVE-2026-89556)

Summary: CVE-2026-89556 kernel: module: validate string table section types
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. This vulnerability arises from insufficient validation of string table section types within ELF (Executable and Linkable Format) files. A local attacker could exploit this by providing a specially crafted ELF module, leading to the kernel attempting to access memory outside of its allocated boundaries. This out-of-bounds memory access could result in system instability, causing a denial of service, or potentially lead to the disclosure of sensitive information.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-09-11 23:27:44 UTC 
In the Linux kernel, the following vulnerability has been resolved:

module: validate string table section types

In elf_validity_cache_sechdrs, section sizes and offsets are validated,
unless the section type is SHT_NULL or SHT_NOBITS.

Later, elf_validity_cache_secstrings and elf_validity_cache_index_str
access the section name table (.shstrtab) and symbol string table
(.strtab) headers without first ensuring that their types are
SHT_STRTAB. If a section type is SHT_NULL or SHT_NOBITS, sh_offset has
not been validated and may reference out-of-bounds memory when
dereferenced in elf_validity_cache_secstrings or
elf_validity_cache_strtab.

Validate that both string section headers are of type SHT_STRTAB before
caching them.
Comment 1 Mauro Matteo Cascella 2026-09-15 11:30:31 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89556.mbox