net: ifb: report ethtool stats over num_tx_queues
Summary
| CVE | CVE-2026-64121 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-19 16:17:53 UTC |
| Updated | 2026-08-13 15:11:43 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 7.1 HIGH from [email protected]
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
EPSS: 0.001730000 probability, percentile 0.069130000 (date 2026-08-02)
Problem Types: CWE-125
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
NoneAvailability
HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Operating System | Linux | Linux Kernel | All | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1 6afdb8113cb007f9332f59a9b7fd45731b8a9de5 git | Not specified |
| CNA | Linux | Linux | affected a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1 16bd798cb6d8337d7c3eea1adc412f31b5181d5b git | Not specified |
| CNA | Linux | Linux | affected a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1 301a554e458e2f5ec47f2c336a7cb03b877f9fd6 git | Not specified |
| CNA | Linux | Linux | affected a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1 f8a5a76b4a683043c6eff2a060bcaa17f9316ad5 git | Not specified |
| CNA | Linux | Linux | affected a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1 2638e1773904d7aa8f24c6e7fda2ed7d69df6fa4 git | Not specified |
| CNA | Linux | Linux | affected a21ee5b2fcb8d6d3973446c5039e966c4cfe40d1 5db89c99566fc4728cc92e941d8e1975711e24b5 git | Not specified |
| CNA | Linux | Linux | affected 5.17 | Not specified |
| CNA | Linux | Linux | unaffected 5.17 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.1.175 6.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.142 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.92 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.34 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.0.11 7.0.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/5db89c99566fc4728cc92e941d8e1975711e24b5 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/f8a5a76b4a683043c6eff2a060bcaa17f9316ad5 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/16bd798cb6d8337d7c3eea1adc412f31b5181d5b | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/2638e1773904d7aa8f24c6e7fda2ed7d69df6fa4 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/301a554e458e2f5ec47f2c336a7cb03b877f9fd6 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/6afdb8113cb007f9332f59a9b7fd45731b8a9de5 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.