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CVE Record

CVE-2021-46931: net/mlx5e: Wrap the tx reporter dump callback to extract the sq

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Wrap the tx reporter dump callback to extract the sq Function mlx5e_tx_reporter_dump_sq() casts its void * argument to struct mlx5e_txqsq *, but in TX-timeout-recovery flow the argument is actually of type struct mlx5e_tx_timeout_ctx *. mlx5_core 0000:08:00.1 enp8s0f1: TX timeout detected mlx5_core 0000:08:00.1 enp8s0f1: TX timeout on queue: 1, SQ: 0x11ec, CQ: 0x146d, SQ Cons: 0x0 SQ Prod: 0x1, usecs since last trans: 21565000 BUG: stack guard page was hit at 0000000093f1a2de (stack is 00000000b66ea0dc..000000004d932dae) kernel stack overflow (page fault): 0000 [#1] SMP NOPTI CPU: 5 PID: 95 Comm: kworker/u20:1 Tainted: G W OE 5.13.0_mlnx #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Workqueue: mlx5e mlx5e_tx_timeout_work [mlx5_core] RIP: 0010:mlx5e_tx_reporter_dump_sq+0xd3/0x180 [mlx5_core] Call Trace: mlx5e_tx_reporter_dump+0x43/0x1c0 [mlx5_core] devlink_health_do_dump.part.91+0x71/0xd0 devlink_health_report+0x157/0x1b0 mlx5e_reporter_tx_timeout+0xb9/0xf0 [mlx5_core] ? mlx5e_tx_reporter_err_cqe_recover+0x1d0/0x1d0 [mlx5_core] ? mlx5e_health_queue_dump+0xd0/0xd0 [mlx5_core] ? update_load_avg+0x19b/0x550 ? set_next_entity+0x72/0x80 ? pick_next_task_fair+0x227/0x340 ? finish_task_switch+0xa2/0x280 mlx5e_tx_timeout_work+0x83/0xb0 [mlx5_core] process_one_work+0x1de/0x3a0 worker_thread+0x2d/0x3c0 ? process_one_work+0x3a0/0x3a0 kthread+0x115/0x130 ? kthread_park+0x90/0x90 ret_from_fork+0x1f/0x30 --[ end trace 51ccabea504edaff ]--- RIP: 0010:mlx5e_tx_reporter_dump_sq+0xd3/0x180 PKRU: 55555554 Kernel panic - not syncing: Fatal exception Kernel Offset: disabled end Kernel panic - not syncing: Fatal exception To fix this bug add a wrapper for mlx5e_tx_reporter_dump_sq() which extracts the sq from struct mlx5e_tx_timeout_ctx and set it as the TX-timeout-recovery flow dump callback.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

A Linux kernel bug in the mlx5e network driver can crash the kernel during TX-timeout recovery. The failure comes from treating diagnostic callback data as the wrong structure type, leading to stack overflow and panic. Business impact is primarily availability loss on affected Linux systems using this driver path.

Executive priority

Treat as an availability risk for Linux infrastructure using mlx5e networking. Patch during the next appropriate maintenance window, sooner for critical hosts with matching drivers or prior TX-timeout instability. There is no source-backed evidence of active exploitation in this bundle.

Technical view

mlx5e_tx_reporter_dump_sq() casts a void pointer to struct mlx5e_txqsq, but TX-timeout recovery passes struct mlx5e_tx_timeout_ctx. The fix adds a wrapper that extracts the queue object before invoking the dump callback. The supplied trace shows devlink health reporting, stack guard hit, kernel stack overflow, and panic.

Likely exposure

Exposure appears limited to Linux kernels with the mlx5e driver and TX-timeout recovery path reachable. The bundle lists Linux kernel affected versions including 5.7, 5.10.90, 5.15.13, and 5.16, but complete version-range semantics are not provided here.

Exploitation context

No active exploitation is reported in the provided bundle, and KEV is false. The source evidence describes a kernel crash during TX timeout handling, not a public exploit chain. Practical risk depends on whether affected systems use the mlx5e driver and can enter this recovery path.

Researcher notes

The root issue is type confusion in a devlink health dump callback during TX-timeout recovery. Evidence is limited to the CVE text and stable kernel references. Do not assume remote exploitability from the provided data; validate driver presence, kernel lineage, and backported fixes.

Mitigation direction

  • Apply vendor kernel updates containing the referenced stable fixes.
  • Prioritize hosts using the mlx5e network driver in production paths.
  • Check distribution advisories for exact fixed package versions.
  • Reduce exposure to untrusted network fault conditions where operationally feasible.

Validation and detection

  • Inventory Linux kernel versions on systems using mlx5e.
  • Confirm whether mlx5_core or mlx5e modules are loaded.
  • Check vendor kernel changelogs for the referenced stable commits.
  • Review logs for TX timeout, devlink health, stack overflow, or kernel panic events.
Prepared
Confidence
medium
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
2ADP providers
4Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

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ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux5f29458b77d51c104554575b73184c243930aa87, 5f29458b77d51c104554575b73184c243930aa87, 5f29458b77d51c104554575b73184c243930aa87unaffected
LinuxLinux5.7, 0, 5.10.90, 5.15.13, 5.16affected
Weakness

CWE details

No CWE listed

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