Description

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.

Classification

CVE ID: CVE-2024-57947

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.05% (probability of being exploited)

EPSS Percentile: 17.97% (scored less or equal to compared to others)

EPSS Date: 2025-02-21 (when was this score calculated)

References

https://git.kernel.org/stable/c/957a4d1c4c5849e4515c9fb4db21bf85318103dc
https://git.kernel.org/stable/c/9625c46ce6fd4f922595a4b32b1de5066d70464f
https://git.kernel.org/stable/c/69b6a67f7052905e928d75a0c5871de50e686986
https://git.kernel.org/stable/c/8058c88ac0df21239daee54b5934d5c80ca9685f
https://git.kernel.org/stable/c/791a615b7ad2258c560f91852be54b0480837c93

Timeline