CVE-2024-49977: net: stmmac: Fix zero-division error when disabling tc cbs

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-10-21 · updated 2026-10-15
Weakness: CWE-369

Description

In the Linux kernel, the following vulnerability has been resolved: net: stmmac: Fix zero-division error when disabling tc cbs The commit b8c43360f6e4 ("net: stmmac: No need to calculate speed divider when offload is disabled") allows the "port_transmit_rate_kbps" to be set to a value of 0, which is then passed to the "div_s64" function when tc-cbs is disabled. This leads to a zero-division error. When tc-cbs is disabled, the idleslope, sendslope, and credit values the credit values are not required to be configured. Therefore, adding a return statement after setting the txQ mode to DCB when tc-cbs is disabled would prevent a zero-division error.

Affected products

Linux kernel: from 5.10.221 before 5.10.227; from 5.15.162 before 5.15.168; from 6.1.96 before 6.1.113; from 6.6.36 before 6.6.55; from 6.9.7 before 6.10; from 6.10 before 6.10.14 — fixed in 5.10.227, 5.15.168, 6.1.113, 6.10, 6.10.14, 6.11.3

How to fix

Upgrade to a fixed version: Linux kernel 5.10.227, 5.15.168, 6.1.113, 6.10. Check the vendor advisory for mitigations.

References

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