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.
History

Wed, 06 Nov 2024 16:15:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 4.4, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2024-04-03T14:54:51.709Z

Updated: 2024-11-06T15:20:28.318Z

Reserved: 2024-02-19T14:20:24.154Z

Link: CVE-2024-26690

cve-icon Vulnrichment

Updated: 2024-08-02T00:14:12.694Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2024-04-03T15:15:52.487

Modified: 2024-11-06T16:35:13.027

Link: CVE-2024-26690

cve-icon Redhat

Severity : Low

Publid Date: 2024-04-03T00:00:00Z

Links: CVE-2024-26690 - Bugzilla