Kernel memory corruption via duplicate send cleanup
Published Apr 24, 2026 · Updated Apr 24, 2026
Double free in the Linux kernel SMB Direct client allows remote attackers to corrupt kernel memory during an RDMA batch-flush failure. The smbd_post_send_iter error path frees a send request after smbd_send_batch_flush has already freed the same request moved onto the batch list. The required ib_post_send failure is an internal hardware or driver error that remote attackers cannot cause, so intentional exploitation is not established.
Summary
What happened
Double free in the Linux kernel SMB Direct client allows remote attackers to corrupt kernel memory during an RDMA batch-flush failure. The smbd_post_send_iter error path frees a send request after smbd_send_batch_flush has already freed the same request moved onto the batch list. The required ib_post_send failure is an internal hardware or driver error that remote attackers cannot cause, so intentional exploitation is not established.
The record
- CVE
- CVE-2026-31609
- Published
- Apr 24, 2026
- Updated
- Apr 24, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-415
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 24, 2026CVE publishedPublication date reported by the CVE source.
- Apr 24, 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <22b7c1c619d808aec4cad3dc42103345e370d107
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a9940dcbe5cb92482c04efc7341039ddf7dbf607
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f9a162c2bbcd0ac85bd07c5b37cf20286048b65c
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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