CVE-2026-90389

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux78f57ef9d50a75326da73d352d7c27828495229a < 72ebfdf507ede7d7f2b7ca0a5634811a0e4bf045affected
LinuxLinux78f57ef9d50a75326da73d352d7c27828495229a < 28fdea874f68cac6c36651b1fc7272fd2199c48daffected
LinuxLinux78f57ef9d50a75326da73d352d7c27828495229a < a58923756b0f8e71032070c23ae0b167e46731daaffected
LinuxLinux78f57ef9d50a75326da73d352d7c27828495229a < bace2010dd7ac07bc980575afb135c406730a7feaffected
LinuxLinux5.8affected
LinuxLinux0 < 5.8unaffected
LinuxLinux6.12.110 <= 6.12.*unaffected
LinuxLinux6.18.52 <= 6.18.*unaffected
LinuxLinux7.2.6 <= 7.2.*unaffected
LinuxLinux7.3-rc1 <= *unaffected

Weaknesses

References