Bug 2341755 (CVE-2024-57947)

Summary: CVE-2024-57947 kernel: netfilter: nf_set_pipapo: fix initial map fill
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: dfreiber, drow, jburrell, vkumar
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2025-01-23 14:01:10 UTC 
In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_set_pipapo: fix initial map fill

The initial buffer has to be inited to all-ones, but it must restrict
it to the size of the first field, not the total field size.

After each round in the map search step, the result and the fill map
are swapped, so if we have a set where f->bsize of the first element
is smaller than m->bsize_max, those one-bits are leaked into future
rounds result map.

This makes pipapo find an incorrect matching results for sets where
first field size is not the largest.

Followup patch adds a test case to nft_concat_range.sh selftest script.

Thanks to Stefano Brivio for pointing out that we need to zero out
the remainder explicitly, only correcting memset() argument isn't enough.
Comment 1 Robb Gatica 2025-01-23 15:42:55 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025012322-CVE-2024-57947-480e@gregkh/T