CVE-2026-90390: md/bitmap: resume array on backlog_store() error path
In the Linux kernel, the following vulnerability has been resolved:
md/bitmap: resume array on backlogstore() error path
backlogstore() suspends the array before checking whether a write-mostly device exists. If no such device exists, the error path only unlocks reconfigmutex and leaves the array suspended, blocking subsequent I/O.
Use mddevunlockandresume() to release both states.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 6.1.176-1Fixed in 6.1.190-1Fixed in 6.12.115-2Fixed in 7.2.12-1Fixed in 7.2.15-1 - Upgrade
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debian/linux-6.12to a version that resolves this vulnerability.Fixed in 6.12.113-1~deb12u1 - Upgrade
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ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42~24.04.1 - Upgrade
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ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1~24.04.1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-42.42 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1016.17 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1016.18 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1015.16 - Upgrade
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ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1
Event History
Frequently Asked Questions
Which systems are exposed to this issue?
Systems using Linux md arrays are exposed when backlog_store() is invoked on an array that has no write-mostly device. The described failure leaves that array suspended and blocks subsequent I/O.
What action triggers the affected error path?
The trigger is an attempt to use backlog_store() when no write-mostly device exists in the array. The array is suspended before that condition is checked, and the pre-fix error path does not resume it.
How can administrators tell whether an array has been affected?
An affected array will remain suspended after the backlog_store() operation fails because no write-mostly device exists. Subsequent I/O to that array is blocked.