Bug 2541211 (CVE-2026-97613)

Summary: CVE-2026-97613 kernel: net: mana: Reserve extra CQ slot for the fence completion CQE
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: low Docs Contact:
Priority: low    
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 Microsoft Azure Network Adapter (MANA) driver. Under heavy network traffic, incoming packet processing can completely fill the receive completion queue, leaving no reserved space for hardware fence synchronization events. This issue causes the completion notification to be dropped and forces the driver to hang while holding the core network configuration lock until a timeout expires, resulting in a denial of service (DoS).
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Description OSIDB Bzimport 2026-09-25 11:02:18 UTC 
In the Linux kernel, the following vulnerability has been resolved:

net: mana: Reserve extra CQ slot for the fence completion CQE

The RX completion queue is sized to hold exactly one CQE per posted RX WQE.
MANA_FENCE_RQ makes hardware post an additional CQE_RX_OBJECT_FENCE after
the packet CQEs. The current sizing reserves no extra slot for it and in
rare cases, CQ has no guaranteed slot for the fence CQE when it is full of
packet CQEs. This can lead to dropping the fence completion while the
driver waits holding RTNL lock throughout the timeout duration.
Reserve one extra CQE slot for CQE_RX_OBJECT_FENCE. mana_gd_alloc_memory()
requires queue_size to be a power-of-two and at least MANA_PAGE_SIZE;
the reservation pushes cq_size past a power-of-two, so round up the CQ size
in mana_create_rxq().
Comment 1 Keith Grant 2026-09-29 15:01:24 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97613.mbox