Kernel crash via firmware fallback completion race
Published Sep 17, 2026 · Updated Sep 17, 2026
Use-after-free in Linux 5.14 firmware_loader allows local users to crash the kernel via raced sysfs completion writes. fw_load_sysfs_fallback() publishes the loading interface before queueing the request, so an early completion leaves a freed request in pending_fw_head and a later fallback request faults while validating the list. Triggering requires an enabled sysfs fallback path, write access to its loading attribute, and completion before queue insertion; the published failure is a kernel fault, not demonstrated code execution.
Summary
What happened
Use-after-free in Linux 5.14 firmware_loader allows local users to crash the kernel via raced sysfs completion writes. fw_load_sysfs_fallback() publishes the loading interface before queueing the request, so an early completion leaves a freed request in pending_fw_head and a later fallback request faults while validating the list. Triggering requires an enabled sysfs fallback path, write access to its loading attribute, and completion before queue insertion; the published failure is a kernel fault, not demonstrated code execution.
The record
- CVE
- CVE-2026-90284
- Published
- Sep 17, 2026
- Updated
- Sep 17, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499.004
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 17, 2026CVE publishedPublication date reported by the CVE source.
- Sep 17, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=4.19.203 <4.20
- Affected versionversion=5.10.58 <5.10.270
- Affected versionversion=5.13.10 <5.14
- Affected versionversion=5.14
- Affected versionversion=5.4.140 <5.5
- Affected versionversion=67cf0fbcac0d42d4d4686cddc1e39f465bbfec37
- Affected versionversion=75d95e2e39b27f733f21e6668af1c9893a97de5e <5a250bff75a446374c05622973b18b4ab662b504
- Affected versionversion=75d95e2e39b27f733f21e6668af1c9893a97de5e <6eaa632d0ed7bbb84f9cb670e5ec4e2cecf4cc7b
- Affected versionversion=75d95e2e39b27f733f21e6668af1c9893a97de5e <85aeb8fc61839098ae0942ccba86e669c08e75d4
- Affected versionversion=75d95e2e39b27f733f21e6668af1c9893a97de5e <93a2385730540105df8524447dcc11309ad280f9
- Affected versionversion=75d95e2e39b27f733f21e6668af1c9893a97de5e <b48373c901951fad1a26bd7c33ad91172b3945b5
- Affected versionversion=75d95e2e39b27f733f21e6668af1c9893a97de5e <ea33fac0df7fe7b49a4b27acb83e227b82317d1d
- Affected versionversion=75d95e2e39b27f733f21e6668af1c9893a97de5e <fb4824880b0dba0e7b3a497c46c642f979630392
- Affected versionversion=c14a54675db7131791402fa22fb0fa6da1f5fb66
- Affected versionversion=d09639528b66b5c7c20dc8f7fb8928aacabd40bb
- Affected versionversion=ecb739cf15a9bae040ce6b60209b78b92512d120 <c8b97c5130f27b64fa2cfe1aa4bebb13f724c6c7
What conditions does exploitation require?
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Published CVSS scores
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Attacks
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Activity data is delayed. The latest report is Sep 28, 2026.
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