CVE-2026-97569bnxt_en: Prevent queue stop with deferred completions
- —Not scoredno CVSS score yet
- 0.21%Exploitation in 30 daysEPSS · top 89% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: bnxt_en: Prevent queue stop with deferred completions When the driver receives a burst of packets, it can mark a BD with the NO_CMPL bit to defer completions. The expectation is that the last packet in the ring will have this bit unset and the completion generated by that packet will cleanup that packet and the ones preceding it. This helps to reduce the number of completions fired. The suppressed completions are controlled by the driver and the number of packets with suppressed completions scales with the size of the ring. SW USO packets, on the other hand, have an upper bound on the maximum number of BDs which can be consumed which does not scale with the ring size. So, for small rings it is possible that: a burst of packets is handed to the driver, the driver defers completions for all of the packets because the number of free descriptors stays above the threshold in the driver. Then, a USO packet arrives, but the number of BDs available is not enough and the USO code exits early. In this case, you end up in a state where the ring is full of packets with their completions suppressed, which can cause the queue to stop and never be restarted. Assuming default CONFIG_MAX_SKB_FRAGS, this is only possible for small rings (<= 457 descriptors, below the driver default value) when a burst of packets fills the ring, followed by a large USO packet that can't fit. For larger rings, the delta between the completion suppression threshold and the BDs required for SW USO is large enough that completions will fire and this case is unreachable. This issue was pointed out by Sashiko and while it seems fairly unlikely given that the queue size must be small to trigger this, it is indeed possible. Fix this by tracking the last BD which deferred completions and centralizing the logic for deciding when to ring the doorbell. The NO_CMPL bit is now cleared in bnxt_txr_db_kick(), so every doorbell site is covered, including the SW USO early exit. This guarantees the ring always ends in a BD which generates a completion to clean it and wake the queue.
Timeline
ID reserved
By Linux
- 1 day later
· 1 day later
Published
- 24 days later
· 24 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
No CVSS score yet: neither the CNA, CISA nor NVD has scored this CVE. NVD status: Received.
- EPSS (exploitation in 30 days)
- 0.21% · top 89% of all CVEs (12 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.
Affected products
References
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-86877 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://cveledger.app/cve/CVE-2026-97569)Record last updated .