Bug 2555017 (CVE-2026-98557)

Summary: CVE-2026-98557 kernel: gve: DQO: fix header length used by gve_can_send_tso() for UDP GSO
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 Google Virtual Ethernet (gve) driver in the Linux kernel. This vulnerability may allow a local attacker to cause a Denial of Service (DoS) by transmitting network traffic that uses User Datagram Protocol (UDP) Generic Segmentation Offload (GSO). Because the driver improperly attempts to read Transmission Control Protocol (TCP) headers on UDP packets, it miscalculates packet header lengths and can submit oversized packet segments to the network device, leading to transmission failures or device stalls.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-10-18 15:39:28 UTC 
In the Linux kernel, the following vulnerability has been resolved:

gve: DQO: fix header length used by gve_can_send_tso() for UDP GSO

gve_can_send_tso() computes how many buffers each segment of a GSO
packet would span, and for this it needs the length of the headers
that the device replicates in front of every segment.

It unconditionally uses skb_tcp_all_headers(), which reads the doff
field of the TCP header. SKB_GSO_UDP_L4 packets have no TCP header:
tcp_hdrlen() then reads one byte of the UDP payload, and header_len
can be anything in [0, 60] instead of the transport offset plus the
eight bytes of the UDP header that gve_prep_tso() programs into the
TSO context descriptor.

A wrong header length shifts all the segment boundaries computed in
the loop, so the number of buffers per segment can be over or under
estimated. In the first case, GSO is needlessly disabled for this
packet by gve_features_check_dqo() and the stack has to segment it.
In the second case, the driver hands the device a packet whose
segments span more than GVE_TX_MAX_DATA_DESCS buffers.

Use the UDP header length for SKB_GSO_UDP_L4 packets, matching what
gve_prep_tso() does.