UBUNTU-CVE-2026-89986: High severity ubuntu/linux-hwe-edge vulnerability

In the Linux kernel, the following vulnerability has been resolved: mm/mempolicy: fix sleeping allocation in allocpagesbulkweightedinterleave() syzbot reported a sleeping function called from invalid context splat in buckettablealloc(). When rhashtableinsertslow() rehashes the table under rcureadlock(), it calls buckettablealloc(..., GFPATOMIC | GFPNOWARN). If the bucket table allocation uses vmalloc, vmallocnoderangenoprof() invokes vmareaallocpages() -> allocpagesbulkmempolicynoprof() with the passed GFPATOMIC flags. If the current task has an MPOLWEIGHTEDINTERLEAVE mempolicy, allocpagesbulkweightedinterleave() is called and currently hardcodes GFPKERNEL when allocating the temporary weights array, triggering a mightalloc() splat in atomic/RCU contexts. Pass the gfp flags (masked with GFPRECLAIMMASK to strip page-allocator zone modifiers like GFPHIGHMEM) received by allocpagesbulkweightedinterleave() to kmalloc() instead of hardcoding GFPKERNEL. Since the weights buffer is immediately initialized in full, kmalloc() is sufficient.