CVE-2026-80862

A flaw was found in the Linux kernel's nvme-tcp component. When block devices are created in parallel threads, the page_frag_cache is used in a manner that is not thread-safe. This can lead to incorrect reference counting of memory pages and premature freeing, potentially causing a system crash (Denial of Service).

A race in the NVMe TCP host path can occur because page_frag_cache is used without serialization while block devices and preallocated requests are initialized in parallel. This can corrupt page reference accounting for PDU backing pages and may cause premature free, followed by warnings in skb_splice_from_iter and random kernel panic. For the CVSS the PR:N is used for the paranoid score because a malicious or compromised NVMe TCP target may influence namespace discovery and request initialization without local code execution on the victim. The issue is best treated as adjacent network reachable in storage fabric deployments rather than a public Internet bug. Impact is at least denial of service via kernel crash and in worst case may allow confidentiality or integrity impact due to memory lifetime corruption and should be reviewed manually.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.