CVE-2025-38162

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nftsetpipapo: prevent overflow in lookup table allocation

When calculating the lookup table size, ensure the following multiplication does not overflow:

• desc->fieldlen[] maximum value is U8MAX multiplied by NFTPIPAPOGROUPSPERBYTE(f) that can be 2, worst case.
• NFTPIPAPOBUCKETS(f->bb) is 2^8, worst case.
• sizeof(unsigned long), from sizeof(*f->lt), lt in struct nftpipapofield.

Then, use checkmuloverflow() to multiply by bucket size and then use checkaddoverflow() to the alignment for avx2 (if needed). Finally, add ltsizecheck_overflow() helper and use it to consolidate this.

While at it, replace leftover allocation using the GFPKERNEL to GFPKERNELACCOUNT for consistency, in pipaporesize().