Bug 2320574 (CVE-2024-49977)

Summary: CVE-2024-49977 kernel: net: stmmac: Fix zero-division error when disabling tc cbs
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
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Hardware: All   
OS: Linux   
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Bug Depends On: 2320950    
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Description OSIDB Bzimport 2024-10-21 19:11:53 UTC
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.

Comment 1 Avinash Hanwate 2024-10-22 12:08:53 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2024102135-CVE-2024-49977-b657@gregkh/T

Comment 2 errata-xmlrpc 2025-05-13 08:30:55 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2025:6966 https://access.redhat.com/errata/RHSA-2025:6966