FKIE_CVE-2026-72343
Vulnerability from fkie_nvd - Published: 2026-08-15 06:22 - Updated: 2026-08-17 06:18
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: Fix HV VHCA stats zero-sized buffer allocation
mlx5e_hv_vhca_stats_create() is called from mlx5e_nic_enable(),
before mlx5e_open(). At that point priv->stats_nch is still zero,
because it is only ever incremented in mlx5e_channel_stats_alloc(),
which is reached only from mlx5e_open_channel().
mlx5e_hv_vhca_stats_buf_size() therefore returns 0, and
kvzalloc(0, GFP_KERNEL) returns ZERO_SIZE_PTR ((void *)16) rather
than NULL. The "if (!buf)" guard does not catch this, and
mlx5e_hv_vhca_stats_create() completes "successfully" with
priv->stats_agent.buf set to ZERO_SIZE_PTR.
Once channels are opened (priv->stats_nch > 0) and the hypervisor
enables stats reporting, mlx5e_hv_vhca_stats_work() recomputes
buf_len using the new non-zero stats_nch and calls
memset(buf, 0, buf_len) on ZERO_SIZE_PTR, faulting at address 0x10.
Allocate the buffer based on priv->max_nch, which is set in
mlx5e_priv_init() and is the upper bound on stats_nch:
- Add a separate helper mlx5e_hv_vhca_stats_buf_max_size() that
returns sizeof(per_ring_stats) * max(max_nch, stats_nch), and
use it for the kvzalloc() in mlx5e_hv_vhca_stats_create().
- Keep mlx5e_hv_vhca_stats_buf_size() (which returns based on
stats_nch) for the worker's active payload size, so the wire
format (block->rings = stats_nch) and the amount of data filled
by mlx5e_hv_vhca_fill_stats() are unchanged.
The max(max_nch, stats_nch) guard handles the rare case where
mlx5e_attach_netdev() recomputes max_nch downward across a
detach/resume cycle while priv->stats_nch persists (mlx5e_detach_netdev
does not call mlx5e_priv_cleanup, so stats_nch is only reset when
the netdev is destroyed). Without the guard, the worker could compute
buf_len from stats_nch and overrun the smaller buffer allocated based
on the reduced max_nch.
Allocating a non-zero buffer also makes the kvzalloc() failure path in
mlx5e_hv_vhca_stats_create() reachable for the first time: it returns
early without (re)creating the agent. Clear
priv->stats_agent.{agent,buf} in mlx5e_hv_vhca_stats_destroy() after
freeing them, so that if a later create() bails out on this path, a
subsequent teardown does not double-free the stale agent/buffer left
from a previous enable/disable cycle.
This mirrors the existing mlx5e pattern of preallocating arrays of
size max_nch (e.g. priv->channel_stats) and lazily populating
entries up to stats_nch on demand.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/net/ethernet/mellanox/mlx5/core/en/hv_vhca_stats.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "3b3a552cf88e10bb7bda88b29cf1fd8267043d50",
"status": "affected",
"version": "fa691d0c9c0812b9045f3a9420862e47b3b92518",
"versionType": "git"
},
{
"lessThan": "5b927dcec5f1087942bf123a82e64a3f66475f01",
"status": "affected",
"version": "fa691d0c9c0812b9045f3a9420862e47b3b92518",
"versionType": "git"
},
{
"lessThan": "22c1d5ecccf92c849bdca1556179aafc95794baf",
"status": "affected",
"version": "fa691d0c9c0812b9045f3a9420862e47b3b92518",
"versionType": "git"
},
{
"lessThan": "420aabb32da4381d8d7cdcaa6a77fad9eaceb0a4",
"status": "affected",
"version": "fa691d0c9c0812b9045f3a9420862e47b3b92518",
"versionType": "git"
},
{
"lessThan": "abc4c56427f144c96b2827a4db3b90eb5b7349a2",
"status": "affected",
"version": "fa691d0c9c0812b9045f3a9420862e47b3b92518",
"versionType": "git"
},
{
"lessThan": "25f6b929c7e379cbea7cb8caa67b49b2d1efae17",
"status": "affected",
"version": "fa691d0c9c0812b9045f3a9420862e47b3b92518",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/net/ethernet/mellanox/mlx5/core/en/hv_vhca_stats.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.17"
},
{
"lessThan": "5.17",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.97",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.40",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: Fix HV VHCA stats zero-sized buffer allocation\n\nmlx5e_hv_vhca_stats_create() is called from mlx5e_nic_enable(),\nbefore mlx5e_open(). At that point priv-\u003estats_nch is still zero,\nbecause it is only ever incremented in mlx5e_channel_stats_alloc(),\nwhich is reached only from mlx5e_open_channel().\n\nmlx5e_hv_vhca_stats_buf_size() therefore returns 0, and\nkvzalloc(0, GFP_KERNEL) returns ZERO_SIZE_PTR ((void *)16) rather\nthan NULL. The \"if (!buf)\" guard does not catch this, and\nmlx5e_hv_vhca_stats_create() completes \"successfully\" with\npriv-\u003estats_agent.buf set to ZERO_SIZE_PTR.\n\nOnce channels are opened (priv-\u003estats_nch \u003e 0) and the hypervisor\nenables stats reporting, mlx5e_hv_vhca_stats_work() recomputes\nbuf_len using the new non-zero stats_nch and calls\nmemset(buf, 0, buf_len) on ZERO_SIZE_PTR, faulting at address 0x10.\n\nAllocate the buffer based on priv-\u003emax_nch, which is set in\nmlx5e_priv_init() and is the upper bound on stats_nch:\n\n - Add a separate helper mlx5e_hv_vhca_stats_buf_max_size() that\n returns sizeof(per_ring_stats) * max(max_nch, stats_nch), and\n use it for the kvzalloc() in mlx5e_hv_vhca_stats_create().\n - Keep mlx5e_hv_vhca_stats_buf_size() (which returns based on\n stats_nch) for the worker\u0027s active payload size, so the wire\n format (block-\u003erings = stats_nch) and the amount of data filled\n by mlx5e_hv_vhca_fill_stats() are unchanged.\n\nThe max(max_nch, stats_nch) guard handles the rare case where\nmlx5e_attach_netdev() recomputes max_nch downward across a\ndetach/resume cycle while priv-\u003estats_nch persists (mlx5e_detach_netdev\ndoes not call mlx5e_priv_cleanup, so stats_nch is only reset when\nthe netdev is destroyed). Without the guard, the worker could compute\nbuf_len from stats_nch and overrun the smaller buffer allocated based\non the reduced max_nch.\n\nAllocating a non-zero buffer also makes the kvzalloc() failure path in\nmlx5e_hv_vhca_stats_create() reachable for the first time: it returns\nearly without (re)creating the agent. Clear\npriv-\u003estats_agent.{agent,buf} in mlx5e_hv_vhca_stats_destroy() after\nfreeing them, so that if a later create() bails out on this path, a\nsubsequent teardown does not double-free the stale agent/buffer left\nfrom a previous enable/disable cycle.\n\nThis mirrors the existing mlx5e pattern of preallocating arrays of\nsize max_nch (e.g. priv-\u003echannel_stats) and lazily populating\nentries up to stats_nch on demand."
}
],
"id": "CVE-2026-72343",
"lastModified": "2026-08-17T06:18:38.163",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 8.4,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 2.5,
"impactScore": 5.9,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2026-08-15T06:22:07.650",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/22c1d5ecccf92c849bdca1556179aafc95794baf"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/25f6b929c7e379cbea7cb8caa67b49b2d1efae17"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/3b3a552cf88e10bb7bda88b29cf1fd8267043d50"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/420aabb32da4381d8d7cdcaa6a77fad9eaceb0a4"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/5b927dcec5f1087942bf123a82e64a3f66475f01"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/abc4c56427f144c96b2827a4db3b90eb5b7349a2"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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