Bug 2502359 (CVE-2026-63986)

Summary: CVE-2026-63986 kernel: ethtool: tsinfo: don't pass ERR_PTR to genlmsg_cancel on prepare failure
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's `ethtool: tsinfo` component. This vulnerability occurs when the `ethnl_tsinfo_prepare_dump()` function fails to properly initialize a generic netlink message (`genlmsg`) but still attempts to cancel it by passing an error pointer. This improper error handling can lead to a system crash, resulting in a Denial of Service (DoS) for the affected system.
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Description OSIDB Bzimport 2026-07-19 16:03:51 UTC 
In the Linux kernel, the following vulnerability has been resolved:

ethtool: tsinfo: don't pass ERR_PTR to genlmsg_cancel on prepare failure

The goto err label leads to:

	genlmsg_cancel(skb, ehdr);
	return ret;

If ethnl_tsinfo_prepare_dump() failed, it has not started a genlmsg.
There's nothing to cancel, and passing an error pointer to
genlmsg_cancel() would cause a crash.
Comment 1 Keith Grant 2026-07-21 23:38:53 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026071903-CVE-2026-63986-0269@gregkh/T