Bug 2546413 (CVE-2026-98365)

Summary: CVE-2026-98365 kernel: RDMA/rxe: Fix integer overflow in mr_check_range() leading to OOB access
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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Doc Text:
A flaw was found in the Linux kernel's Remote Direct Memory Access (RDMA) software driver. An unauthenticated remote attacker can cause a Denial of Service (DoS) or out-of-bounds memory access by sending specially crafted network requests that trigger an integer overflow during memory range validation. This flaw allows invalid requests to bypass boundary checks, resulting in a system crash.
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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 2026-10-06 09:16:55 UTC
In the Linux kernel, the following vulnerability has been resolved:

RDMA/rxe: Fix integer overflow in mr_check_range() leading to OOB access

mr_check_range() validates that [iova, iova+length) falls within the
registered MR range using wraparound-prone arithmetic:

    if (iova < mr->ibmr.iova ||
        iova + length > mr->ibmr.iova + mr->ibmr.length)

A remote peer can craft an RDMA-Write/Read RETH so that iova + length
wraps to 0 (e.g. iova=0xfffffffffffffff8, length=8), bypassing the
check. rxe_mr_iova_to_index() then computes a huge index (int idx, only
guarded by WARN_ON) and rxe_mr_copy_xarray() dereferences
mr->page_info[huge], causing an out-of-bounds read/write and a kernel
oops that is triggerable by an unauthenticated remote peer.

Rewrite the check in overflow-safe form; the first two clauses guarantee
that the subsequent subtractions do not underflow:

    if (iova < mr->ibmr.iova ||
        length > mr->ibmr.length ||
        iova - mr->ibmr.iova > mr->ibmr.length - length)

With the fix, mr_check_range() returns -EINVAL for the crafted iova and
the responder reports REMOTE_ACCESS_ERROR instead of triggering the OOB.