CVE-2026-68287

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

drop_monitor: fix size calculations for 64-bit attributes

netdmpacketreportfill() and netdmhwpacketreportfill() use nlaputu6464bit() to append 64-bit attributes (NETDMATTRPC and NETDMATTRTIMESTAMP).

On 32-bit architectures without CONFIGHAVEEFFICIENTUNALIGNEDACCESS, nlaputu6464bit() may append a 4-byte NETDMATTRPAD attribute for 64-bit alignment.

However, netdmpacketreportsize() and netdmhwpacketreportsize() used nlatotalsize(sizeof(u64)) instead of nlatotalsize64bit(sizeof(u64)), budgeting 12 bytes instead of up to 16 bytes.

This under-estimation of SKB size can lead to an skboverpanic() when __nlareserve() or skbput() is subsequently called.

Fix this by using nlatotalsize_64bit(sizeof(u64)) in both size calculations.