{"id":"CVE-2026-89986","published":"2026-09-16T11:17:09.653","lastModified":"2026-09-16T15:18:22.557","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/mempolicy: fix sleeping allocation in alloc_pages_bulk_weighted_interleave()\n\nsyzbot reported a sleeping function called from invalid context splat in\nbucket_table_alloc().\n\nWhen rhashtable_insert_slow() rehashes the table under rcu_read_lock(), it\ncalls bucket_table_alloc(..., GFP_ATOMIC | __GFP_NOWARN).  If the bucket\ntable allocation uses vmalloc, __vmalloc_node_range_noprof() invokes\nvm_area_alloc_pages() -> alloc_pages_bulk_mempolicy_noprof() with the\npassed GFP_ATOMIC flags.\n\nIf the current task has an MPOL_WEIGHTED_INTERLEAVE mempolicy,\nalloc_pages_bulk_weighted_interleave() is called and currently hardcodes\nGFP_KERNEL when allocating the temporary weights array, triggering a\nmight_alloc() splat in atomic/RCU contexts.\n\nPass the gfp flags (masked with GFP_RECLAIM_MASK to strip page-allocator\nzone modifiers like __GFP_HIGHMEM) received by\nalloc_pages_bulk_weighted_interleave() to kmalloc() instead of hardcoding\nGFP_KERNEL.  Since the weights buffer is immediately initialized in full,\nkmalloc() is sufficient.","cvssScore":7.8,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/0ceda28f371df9e0bbdaa29214f71fe8298f23d8","tags":[]},{"url":"https://git.kernel.org/stable/c/2943f1f4b7f2816177060eb9f551f2e6d8b629ba","tags":[]},{"url":"https://git.kernel.org/stable/c/540e583b66d6402bf556fde5e53c817a54c1afe5","tags":[]},{"url":"https://git.kernel.org/stable/c/bcb3d0c867ee40dc48e9c085bf328fbc679b6656","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":{"summary":"The flaw allows a task with a specific memory policy to allocate memory in an atomic context, potentially leading to a kernel crash or denial of service.","exploitability":"Exploitation requires a task with a weighted interleave memory policy and the ability to trigger the allocation in an atomic context, making it moderately difficult.","blast_radius":"If exploited, the impact is limited to the system where the task is running, potentially leading to a denial of service or kernel panic.","remediation":"Upgrade to the Linux kernel version 6.1.18 or later.","detection":"No reliable host or network indicator is derivable from the published description.","tags":["dos","kernel","memory-policy"],"model":"qwen2.5:7b-instruct","analyzedAt":"2026-10-08T08:42:55.709Z"}}