IRQ double-free via mismatched device identifier
Published Dec 28, 2024 · Updated Aug 5, 2026
Improper IRQ release in the Linux 9p/Xen transport allows local users to trigger a double-free during affected-kernel device teardown. xen_9pfs_front_free passed the Xen device pointer to unbind_from_irqhandler instead of the ring pointer used when binding the IRQ. The path is limited to Xen guests and requires CAP_SYS_ADMIN; public sources report the double-free warning but no reliable crash or code-execution outcome.
Summary
What happened
Improper IRQ release in the Linux 9p/Xen transport allows local users to trigger a double-free during affected-kernel device teardown. xen_9pfs_front_free passed the Xen device pointer to unbind_from_irqhandler instead of the ring pointer used when binding the IRQ. The path is limited to Xen guests and requires CAP_SYS_ADMIN; public sources report the double-free warning but no reliable crash or code-execution outcome.
The record
- CVE
- CVE-2024-56704
- Published
- Dec 28, 2024
- Updated
- Aug 5, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-415
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Dec 28, 2024CVE publishedPublication date reported by the CVE source.
- Aug 5, 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?
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- Affected versionversion=4.12
- Affected versionversion=71ebd71921e451f0f942ddfe85d01e31ddc6eb88 <2bb3ee1bf237557daea1d58007d2e1d4a6502ccf
- Affected versionversion=71ebd71921e451f0f942ddfe85d01e31ddc6eb88 <4950408793b118cb8075bcee1f033b543fb719fa
- Affected versionversion=71ebd71921e451f0f942ddfe85d01e31ddc6eb88 <530bc9f03a102fac95b07cda513bfc16ff69e0ee
- Affected versionversion=71ebd71921e451f0f942ddfe85d01e31ddc6eb88 <692eb06703afc3e24d889d77e94a0e20229f6a4a
- Affected versionversion=71ebd71921e451f0f942ddfe85d01e31ddc6eb88 <7f5a2ed5c1810661e6b03f5a4ebf17682cdea850
- Affected versionversion=71ebd71921e451f0f942ddfe85d01e31ddc6eb88 <b9e26059664bd9ebc64a0e8f5216266fc9f84265
- Affected versionversion=71ebd71921e451f0f942ddfe85d01e31ddc6eb88 <d74b4b297097bd361b8a9abfde9b521ff464ea9c
- Affected versionversion=71ebd71921e451f0f942ddfe85d01e31ddc6eb88 <d888f5f5d76b2722c267e6bdf51d445d60647b7b
- Affected versionversion=71ebd71921e451f0f942ddfe85d01e31ddc6eb88 <e43c608f40c065b30964f0a806348062991b802d
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
Public exploit references
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Technologies
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Your stack
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