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CVE-2021-47556 is a NULL pointer dereference in the Linux kernel ethtool legacy ioctl path for changing network-interface interrupt-coalescing settings. The ethtool_set_coalesce() logic uses both driver get_coalesce and set_coalesce callbacks, but its availability check does not ensure that both callbacks are implemented. A driver implementing only one required callback can therefore cause ethtool to invoke a NULL callback rather than return an unsupported-operation error.
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Linux kernel vulnerability addressed by this kernel-rt update; no issue description is provided in the content.
A Linux kernel vulnerability addressed by this advisory; technical details are not provided in the content.
A moderate-severity Linux kernel ethtool ioctl flaw (CWE-476) in coalesce-settings handling. Missing validation of required callbacks can cause a NULL-pointer dereference and local denial of service through system instability or crashes during network operations.
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Every observed campaign linking this CVE to a named adversary.
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Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.