CVE-2021-47587net: systemport: Add global locking for descriptor lifecycle
- 9.8CriticalCVSS base score
- 0.55%Exploitation in 30 daysEPSS · top 54% 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: net: systemport: Add global locking for descriptor lifecycle The descriptor list is a shared resource across all of the transmit queues, and the locking mechanism used today only protects concurrency across a given transmit queue between the transmit and reclaiming. This creates an opportunity for the SYSTEMPORT hardware to work on corrupted descriptors if we have multiple producers at once which is the case when using multiple transmit queues. This was particularly noticeable when using multiple flows/transmit queues and it showed up in interesting ways in that UDP packets would get a correct UDP header checksum being calculated over an incorrect packet length. Similarly TCP packets would get an equally correct checksum computed by the hardware over an incorrect packet length. The SYSTEMPORT hardware maintains an internal descriptor list that it re-arranges when the driver produces a new descriptor anytime it writes to the WRITE_PORT_{HI,LO} registers, there is however some delay in the hardware to re-organize its descriptors and it is possible that concurrent TX queues eventually break this internal allocation scheme to the point where the length/status part of the descriptor gets used for an incorrect data buffer. The fix is to impose a global serialization for all TX queues in the short section where we are writing to the WRITE_PORT_{HI,LO} registers which solves the corruption even with multiple concurrent TX queues being used.
Timeline
ID reserved
By Linux
- 26 days later
· 26 days later
Published
- 2 years later
· 2 years 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
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.55% · top 54% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Affected products
- affected 80105befdb4b8cea924711b40b2462b87df65b62 – < 8ed2f5d08d6e59f8c78b2869bfb95d0be32c094c
- affected 80105befdb4b8cea924711b40b2462b87df65b62 – < de57f62f76450b934de8203711bdc4f7953c3421
- affected 80105befdb4b8cea924711b40b2462b87df65b62 – < f3fde37d3f0d429f0fcce214cb52588a9e21260e
- affected 80105befdb4b8cea924711b40b2462b87df65b62 – < 595a684fa6f23b21958379a18cfa83862c73c2e1
- affected 80105befdb4b8cea924711b40b2462b87df65b62 – < c675256a7f131f5ba3f331efb715e8f31ea0e392
- affected 80105befdb4b8cea924711b40b2462b87df65b62 – < 6e1011cd183faae8daff275c72444edcdfe0d473
- affected 80105befdb4b8cea924711b40b2462b87df65b62 – < eb4687c7442942e115420a30185f8d83faf37696
- affected 80105befdb4b8cea924711b40b2462b87df65b62 – < 8b8e6e782456f1ce02a7ae914bbd5b1053f0b034
- affected 3.16
- unaffected < 3.16
- unaffected 4.4.296 – ≤ 4.4.*
- unaffected 4.9.294 – ≤ 4.9.*
- unaffected 4.14.259 – ≤ 4.14.*
- unaffected 4.19.222 – ≤ 4.19.*
- unaffected 5.4.168 – ≤ 5.4.*
- unaffected 5.10.88 – ≤ 5.10.*
- unaffected 5.15.11 – ≤ 5.15.*
- unaffected 5.16 – ≤ *
References
References8
- https://git.kernel.org/stable/c/8ed2f5d08d6e59f8c78b2869bfb95d0be32c094c (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/de57f62f76450b934de8203711bdc4f7953c3421 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/f3fde37d3f0d429f0fcce214cb52588a9e21260e (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/595a684fa6f23b21958379a18cfa83862c73c2e1 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/c675256a7f131f5ba3f331efb715e8f31ea0e392 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/6e1011cd183faae8daff275c72444edcdfe0d473 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/eb4687c7442942e115420a30185f8d83faf37696 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/8b8e6e782456f1ce02a7ae914bbd5b1053f0b034 (opens in a new tab)x_transferred
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-2021-34589 (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)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2021-47587)Record last updated .