CVE-2024-26690: In the Linux kernel, the following vulnerability has been resolved: net: stmmac: protect updates of 64-bit statistics counters As explained by a com...

Description

In the Linux kernel, the following vulnerability has been resolved: net: stmmac: protect updates of 64-bit statistics counters As explained by a comment in <linux/u64_stats_sync.h>, write side of struct u64_stats_sync must ensure mutual exclusion, or one seqcount update could be lost on 32-bit platforms, thus blocking readers forever. Such lockups have been observed in real world after stmmac_xmit() on one CPU raced with stmmac_napi_poll_tx() on another CPU. To fix the issue without introducing a new lock, split the statics into three parts: 1. fields updated only under the tx queue lock, 2. fields updated only during NAPI poll, 3. fields updated only from interrupt context, Updates to fields in the first two groups are already serialized through other locks. It is sufficient to split the existing struct u64_stats_sync so that each group has its own. Note that tx_set_ic_bit is updated from both contexts. Split this counter so that each context gets its own, and calculate their sum to get the total value in stmmac_get_ethtool_stats(). For the third group, multiple interrupts may be processed by different CPUs at the same time, but interrupts on the same CPU will not nest. Move fields from this group to a newly created per-cpu struct stmmac_pcpu_stats.

Metrics

CVSS 3.1

6.5/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

EPSS Probability

0.71%

48.8th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions	Update
Linux	Linux Kernel	>= 6.6, < 6.6.18	—
Linux	Linux Kernel	>= 6.7, < 6.7.6	—
Linux	Linux Kernel	6.8	Rc1

References

Timeline

Published: Apr 3, 2024
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2024-26690?

In the Linux kernel, the following vulnerability has been resolved: net: stmmac: protect updates of 64-bit statistics counters As explained by a comment in <linux/u64_stats_sync.h>, write side of struct u64_stats_sync must ensure mutual exclusion, or one seqcount update could be lost on 32-bit platforms, thus blocking readers forever. Such lockups have been observed in real world after stmmac_xmit() on one CPU raced with stmmac_napi_poll_tx() on another CPU. To fix the issue without introducing a new lock, split the statics into three parts: 1. fields updated only under the tx queue lock, 2. fields updated only during NAPI poll, 3. fields updated only from interrupt context, Updates to fields in the first two groups are already serialized through other locks. It is sufficient to split the existing struct u64_stats_sync so that each group has its own. Note that tx_set_ic_bit is updated from both contexts. Split this counter so that each context gets its own, and calculate their sum to get the total value in stmmac_get_ethtool_stats(). For the third group, multiple interrupts may be processed by different CPUs at the same time, but interrupts on the same CPU will not nest. Move fields from this group to a newly created per-cpu struct stmmac_pcpu_stats.

How severe is CVE-2024-26690?

CVE-2024-26690 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.71% probability of exploitation in the next 30 days.

How do I fix CVE-2024-26690?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.