CVE-2024-56592

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 6.6.74

Description The issue arises when a map is removed from the htab, potentially holding the last reference of the map. This triggers a lockdep warning due to the acquisition of map idr lock while holding a bucket lock. The warning is caused by bpf map fd put ptr() invoking bpf map free id() under a raw spin lock, which attempts to acquire map idr lock. To fix this, htab put fd value() is invoked after htab unlock bucket(), and free htab elem() is also deferred to link to-be-freed elements together.

Recommendations For Linux kernel versions prior to 6.6.74, update to version 6.6.74 or later to resolve the issue. As a temporary workaround, consider deferring the invocation of htab put fd value() and free htab elem() after htab unlock bucket() to prevent the lockdep warning.