md: scope memalloc_noio to allocation critical sections

In the Linux kernel, the following vulnerability has been resolved: md: scope memalloc_noio to allocation critical sections Storing a memalloc_noio_save() token in mddev->noio_flags lets one task save the token and another task restore it. With concurrent suspend sysfs writes, task A can enter PF_MEMALLOC_NOIO, return to userspace still in that scope, and later task B can restore A's saved token. Avoid tying the token lifetime to mddev. Keep mddev_suspend() and mddev_resume() only responsible for array suspension, and enter PF_MEMALLOC_NOIO only in the MD paths that allocate memory after the array has been suspended. Restore the token before resuming the array. A reproducer repeatedly writes suspend_lo and suspend_hi from concurrent workers and checks each worker's /proc/self/stat flags before and after the sysfs write.

Source published

17 Sep 2026 16:09:23 UTC

Source modified

19 Oct 2026 09:02:53 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.