Kernel crash via absent-VF bridge operation
Published Sep 27, 2024 · Updated May 11, 2026
NULL pointer dereference in the Linux kernel mlx5 driver allows local users to crash the kernel through an mlx5 bridge mode request. When no virtual functions exist, the bridge set/get path dereferences the uninitialized esw->fdb_table.legacy.vepa_fdb pointer while handling the PF interface. Reachability requires local low-privileged access to a system using the mlx5 driver with an SR-IOV physical function configured with zero virtual functions; triggering the write operation causes a host-wide service interrupt.
Summary
What happened
NULL pointer dereference in the Linux kernel mlx5 driver allows local users to crash the kernel through an mlx5 bridge mode request. When no virtual functions exist, the bridge set/get path dereferences the uninitialized esw->fdb_table.legacy.vepa_fdb pointer while handling the PF interface. Reachability requires local low-privileged access to a system using the mlx5 driver with an SR-IOV physical function configured with zero virtual functions; triggering the write operation causes a host-wide service interrupt.
The record
- CVE
- CVE-2024-46857
- Published
- Sep 27, 2024
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-476, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 27, 2024CVE publishedPublication date reported by the CVE source.
- May 11, 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=4b89251de024fb85329e4cbd8fbea551ae6c665c <505ae01f75f839b54329164bbfecf24cc1361b31
- Affected versionversion=4b89251de024fb85329e4cbd8fbea551ae6c665c <52c4beb79e095e0631b5cac46ed48a2aefe51985
- Affected versionversion=4b89251de024fb85329e4cbd8fbea551ae6c665c <65feee671e37f3b6eda0b6af28f204b5bcf7fa50
- Affected versionversion=4b89251de024fb85329e4cbd8fbea551ae6c665c <b1d305abef4640af1b4f1b4774d513cd81b10cfc
- Affected versionversion=5.1
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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Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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