Bug 2536488 (CVE-2026-90327)

Summary: CVE-2026-90327 kernel: phonet: pep: do not write beyond optlen in getsockopt
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: 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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Doc Text:
A flaw was found in the Linux kernel's `phonet: pep` component. A local attacker could exploit an out-of-bounds write vulnerability in the `pep_getsockopt()` function. This occurs when a `getsockopt()` call provides an `optlen` smaller than `sizeof(int)`, causing the function to write a full integer beyond the user-provided buffer. This could lead to memory corruption and potentially information disclosure or denial of service.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-09-17 18:11:43 UTC 
In the Linux kernel, the following vulnerability has been resolved:

phonet: pep: do not write beyond optlen in getsockopt

pep_getsockopt() clamps the reported length to the caller's buffer with
min_t(), but then stores the value with put_user(val, (int __user *)
optval), which always writes sizeof(int) bytes. A getsockopt() call with
an optlen smaller than sizeof(int) thus reports the clamped length yet
writes a full int, one to three bytes past the user buffer.

Write the value with copy_to_user() bounded by len, so at most optlen
bytes are copied, matching the length reported back to userspace.
Comment 1 gkamathe 2026-09-23 10:43:51 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-90327.mbox