CVE-2026-64121net: ifb: report ethtool stats over num_tx_queues
- 7.1HighCVSS base score
- 0.13%Exploitation in 30 daysEPSS · top 98% 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: ifb: report ethtool stats over num_tx_queues ifb_dev_init() allocates dp->tx_private to dev->num_tx_queues entries via kzalloc_objs(*txp, dev->num_tx_queues). Both IFB per-queue RX and TX stats live in those entries: ifb_xmit() updates txp->rx_stats using the skb queue mapping, ifb_ri_tasklet() updates txp->tx_stats, and ifb_stats64() aggregates both over dev->num_tx_queues. The ethtool stats callbacks instead size and walk the per-queue stats with dev->real_num_rx_queues and dev->real_num_tx_queues. With an asymmetric device where the RX queue count exceeds the TX queue count, for example: ip link add name ifb10 numtxqueues 1 numrxqueues 8 type ifb ethtool -S ifb10 ifb_get_ethtool_stats() indexes past the tx_private allocation and copies adjacent slab data through ETHTOOL_GSTATS. Use dev->num_tx_queues consistently for the stats strings, the stats count, and the stats data walks. This reports one RX stats group and one TX stats group for each backing ifb_q_private entry, which is the queue set IFB can actually populate. Reproduced under UML+KASAN at v7.1-rc2: BUG: KASAN: slab-out-of-bounds in ifb_fill_stats_data+0x3c/0xae Read of size 8 at addr 0000000062dbd228 by task ethtool/36 ifb_fill_stats_data+0x3c/0xae ifb_get_ethtool_stats+0xc0/0x129 __dev_ethtool+0x1ca5/0x363c dev_ethtool+0x123/0x1b3 dev_ioctl+0x56c/0x744 sock_do_ioctl+0x15f/0x1b2 sock_ioctl+0x4d5/0x50a sys_ioctl+0xd8b/0xde9 With the patch applied, the same UML+KASAN repro is silent and ethtool -S ifb10 reports only the stats backed by the single allocated tx_private entry.
Timeline
ID reserved
By Linux
Published
- 4 months later
· 4 months 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 |
|---|---|---|---|
| NVDNVD · Analyzed | 3.1 | High7.1 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.13% · top 98% of all CVEs (14 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: High 7.1.
Affected products
- affected a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1 – < 6afdb8113cb007f9332f59a9b7fd45731b8a9de5
- affected a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1 – < 16bd798cb6d8337d7c3eea1adc412f31b5181d5b
- affected a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1 – < 301a554e458e2f5ec47f2c336a7cb03b877f9fd6
- affected a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1 – < f8a5a76b4a683043c6eff2a060bcaa17f9316ad5
- affected a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1 – < 2638e1773904d7aa8f24c6e7fda2ed7d69df6fa4
- affected a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1 – < 5db89c99566fc4728cc92e941d8e1975711e24b5
- affected 5.17
- unaffected < 5.17
- unaffected 6.1.175 – ≤ 6.1.*
- unaffected 6.6.142 – ≤ 6.6.*
- unaffected 6.12.92 – ≤ 6.12.*
- unaffected 6.18.34 – ≤ 6.18.*
- unaffected 7.0.11 – ≤ 7.0.*
- unaffected 7.1 – ≤ *
References
References6
- https://git.kernel.org/stable/c/6afdb8113cb007f9332f59a9b7fd45731b8a9de5 (opens in a new tab)
- https://git.kernel.org/stable/c/16bd798cb6d8337d7c3eea1adc412f31b5181d5b (opens in a new tab)
- https://git.kernel.org/stable/c/301a554e458e2f5ec47f2c336a7cb03b877f9fd6 (opens in a new tab)
- https://git.kernel.org/stable/c/f8a5a76b4a683043c6eff2a060bcaa17f9316ad5 (opens in a new tab)
- https://git.kernel.org/stable/c/2638e1773904d7aa8f24c6e7fda2ed7d69df6fa4 (opens in a new tab)
- https://git.kernel.org/stable/c/5db89c99566fc4728cc92e941d8e1975711e24b5 (opens in a new tab)
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-2026-45806 (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-2026-64121)Record last updated .