FKIE_CVE-2026-46110
Vulnerability from fkie_nvd - Published: 2026-05-28 10:16 - Updated: 2026-06-24 18:28
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
net: stmmac: Prevent NULL deref when RX memory exhausted
The CPU receives frames from the MAC through conventional DMA: the CPU
allocates buffers for the MAC, then the MAC fills them and returns
ownership to the CPU. For each hardware RX queue, the CPU and MAC
coordinate through a shared ring array of DMA descriptors: one
descriptor per DMA buffer. Each descriptor includes the buffer's
physical address and a status flag ("OWN") indicating which side owns
the buffer: OWN=0 for CPU, OWN=1 for MAC. The CPU is only allowed to set
the flag and the MAC is only allowed to clear it, and both must move
through the ring in sequence: thus the ring is used for both
"submissions" and "completions."
In the stmmac driver, stmmac_rx() bookmarks its position in the ring
with the `cur_rx` index. The main receive loop in that function checks
for rx_descs[cur_rx].own=0, gives the corresponding buffer to the
network stack (NULLing the pointer), and increments `cur_rx` modulo the
ring size. After the loop exits, stmmac_rx_refill(), which bookmarks its
position with `dirty_rx`, allocates fresh buffers and rearms the
descriptors (setting OWN=1). If it fails any allocation, it simply stops
early (leaving OWN=0) and will retry where it left off when next called.
This means descriptors have a three-stage lifecycle (terms my own):
- `empty` (OWN=1, buffer valid)
- `full` (OWN=0, buffer valid and populated)
- `dirty` (OWN=0, buffer NULL)
But because stmmac_rx() only checks OWN, it confuses `full`/`dirty`. In
the past (see 'Fixes:'), there was a bug where the loop could cycle
`cur_rx` all the way back to the first descriptor it dirtied, resulting
in a NULL dereference when mistaken for `full`. The aforementioned
commit resolved that *specific* failure by capping the loop's iteration
limit at `dma_rx_size - 1`, but this is only a partial fix: if the
previous stmmac_rx_refill() didn't complete, then there are leftover
`dirty` descriptors that the loop might encounter without needing to
cycle fully around. The current code therefore panics (see 'Closes:')
when stmmac_rx_refill() is memory-starved long enough for `cur_rx` to
catch up to `dirty_rx`.
Fix this by explicitly checking, before advancing `cur_rx`, if the next
entry is dirty; exit the loop if so. This prevents processing of the
final, used descriptor until stmmac_rx_refill() succeeds, but
fully prevents the `cur_rx == dirty_rx` ambiguity as the previous bugfix
intended: so remove the clamp as well. Since stmmac_rx_zc() is a
copy-paste-and-tweak of stmmac_rx() and the code structure is identical,
any fix to stmmac_rx() will also need a corresponding fix for
stmmac_rx_zc(). Therefore, apply the same check there.
In stmmac_rx() (not stmmac_rx_zc()), a related bug remains: after the
MAC sets OWN=0 on the final descriptor, it will be unable to send any
further DMA-complete IRQs until it's given more `empty` descriptors.
Currently, the driver simply *hopes* that the next stmmac_rx_refill()
succeeds, risking an indefinite stall of the receive process if not. But
this is not a regression, so it can be addressed in a future change.
References
Impacted products
| Vendor | Product | Version | |
|---|---|---|---|
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | 6.7 | |
| linux | linux_kernel | 6.7 | |
| linux | linux_kernel | 6.7 | |
| linux | linux_kernel | 6.7 | |
| linux | linux_kernel | 6.7 | |
| linux | linux_kernel | 6.7 | |
| linux | linux_kernel | 6.7 | |
| linux | linux_kernel | 6.7 | |
| linux | linux_kernel | 7.1 |
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/net/ethernet/stmicro/stmmac/stmmac_main.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "fdeb95b1fc7de25c9362990efb9996a8d761055c",
"status": "affected",
"version": "7414a28de1b3b028714859078c00a874f9feff52",
"versionType": "git"
},
{
"lessThan": "e1c50b273298c7cd9b08b113e7a7598b531a02f5",
"status": "affected",
"version": "779334e59850f863bf34665e0ff0b6faf126873b",
"versionType": "git"
},
{
"lessThan": "5c910f7708e3c507b037ca91ca5b09f8cfe71e65",
"status": "affected",
"version": "b6cb4541853c7ee512111b0e7ddf3cb66c99c137",
"versionType": "git"
},
{
"lessThan": "4af2e62cbcda575a174acd230c3f3a208135e16d",
"status": "affected",
"version": "b6cb4541853c7ee512111b0e7ddf3cb66c99c137",
"versionType": "git"
},
{
"lessThan": "950cb436165aad0f8f2cd49da3cd07677465bcde",
"status": "affected",
"version": "b6cb4541853c7ee512111b0e7ddf3cb66c99c137",
"versionType": "git"
},
{
"lessThan": "0bb05e6adfa99a2ea1fee1125cc0953409f83ed8",
"status": "affected",
"version": "b6cb4541853c7ee512111b0e7ddf3cb66c99c137",
"versionType": "git"
},
{
"status": "affected",
"version": "b435b4573240b5530830a1a60e005c6fcfd928a0",
"versionType": "git"
},
{
"lessThan": "6.1.176",
"status": "affected",
"version": "6.1.64",
"versionType": "semver"
},
{
"lessThan": "6.6.140",
"status": "affected",
"version": "6.6.3",
"versionType": "semver"
},
{
"lessThan": "6.6",
"status": "affected",
"version": "6.5.13",
"versionType": "semver"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/net/ethernet/stmicro/stmmac/stmmac_main.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.7"
},
{
"lessThan": "6.7",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.176",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.140",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.88",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.30",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.0.*",
"status": "unaffected",
"version": "7.0.7",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "7D2385BE-AA5B-4108-986E-94FE78869E0B",
"versionEndExcluding": "6.1.176",
"versionStartIncluding": "6.1.64",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "3B6AC16B-2F1C-4FDF-8F49-09FC11C3F5B0",
"versionEndExcluding": "6.6",
"versionStartIncluding": "6.5.13",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "5BEAFABA-7E5B-445F-93D8-C490B82429EC",
"versionEndExcluding": "6.6.140",
"versionStartIncluding": "6.6.3",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "269B1B34-9934-4742-8224-E11B647B979B",
"versionEndExcluding": "6.12.88",
"versionStartIncluding": "6.7.1",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "BF39AE08-AE6D-4410-8FBE-76F6BF5BF55B",
"versionEndExcluding": "6.18.30",
"versionStartIncluding": "6.13",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "D0893CA7-9AE6-4DFE-AC75-48967D73AD8E",
"versionEndExcluding": "7.0.7",
"versionStartIncluding": "6.19",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.7:-:*:*:*:*:*:*",
"matchCriteriaId": "62B55B1B-7D3E-499B-9C42-E9F1EF05A54A",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.7:rc2:*:*:*:*:*:*",
"matchCriteriaId": "E31AD4FC-436C-44AB-BCAB-3A0B37F69EE0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.7:rc3:*:*:*:*:*:*",
"matchCriteriaId": "C56C6E04-4F04-44A3-8DB8-93899903CFCF",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.7:rc4:*:*:*:*:*:*",
"matchCriteriaId": "5C78EDA4-8BE6-42FC-9512-49032D525A55",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.7:rc5:*:*:*:*:*:*",
"matchCriteriaId": "32F2E5CA-13C6-4601-B530-D465CBF73D1C",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.7:rc6:*:*:*:*:*:*",
"matchCriteriaId": "5ED5AF93-F831-48BC-9545-CCB344E814FC",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.7:rc7:*:*:*:*:*:*",
"matchCriteriaId": "81A7ABCB-0807-4AA2-8F4E-75E38D2E3FD4",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.7:rc8:*:*:*:*:*:*",
"matchCriteriaId": "B01471D6-2DB4-4AF2-8BE0-B5082B4B9253",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*",
"matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: stmmac: Prevent NULL deref when RX memory exhausted\n\nThe CPU receives frames from the MAC through conventional DMA: the CPU\nallocates buffers for the MAC, then the MAC fills them and returns\nownership to the CPU. For each hardware RX queue, the CPU and MAC\ncoordinate through a shared ring array of DMA descriptors: one\ndescriptor per DMA buffer. Each descriptor includes the buffer\u0027s\nphysical address and a status flag (\"OWN\") indicating which side owns\nthe buffer: OWN=0 for CPU, OWN=1 for MAC. The CPU is only allowed to set\nthe flag and the MAC is only allowed to clear it, and both must move\nthrough the ring in sequence: thus the ring is used for both\n\"submissions\" and \"completions.\"\n\nIn the stmmac driver, stmmac_rx() bookmarks its position in the ring\nwith the `cur_rx` index. The main receive loop in that function checks\nfor rx_descs[cur_rx].own=0, gives the corresponding buffer to the\nnetwork stack (NULLing the pointer), and increments `cur_rx` modulo the\nring size. After the loop exits, stmmac_rx_refill(), which bookmarks its\nposition with `dirty_rx`, allocates fresh buffers and rearms the\ndescriptors (setting OWN=1). If it fails any allocation, it simply stops\nearly (leaving OWN=0) and will retry where it left off when next called.\n\nThis means descriptors have a three-stage lifecycle (terms my own):\n- `empty` (OWN=1, buffer valid)\n- `full` (OWN=0, buffer valid and populated)\n- `dirty` (OWN=0, buffer NULL)\n\nBut because stmmac_rx() only checks OWN, it confuses `full`/`dirty`. In\nthe past (see \u0027Fixes:\u0027), there was a bug where the loop could cycle\n`cur_rx` all the way back to the first descriptor it dirtied, resulting\nin a NULL dereference when mistaken for `full`. The aforementioned\ncommit resolved that *specific* failure by capping the loop\u0027s iteration\nlimit at `dma_rx_size - 1`, but this is only a partial fix: if the\nprevious stmmac_rx_refill() didn\u0027t complete, then there are leftover\n`dirty` descriptors that the loop might encounter without needing to\ncycle fully around. The current code therefore panics (see \u0027Closes:\u0027)\nwhen stmmac_rx_refill() is memory-starved long enough for `cur_rx` to\ncatch up to `dirty_rx`.\n\nFix this by explicitly checking, before advancing `cur_rx`, if the next\nentry is dirty; exit the loop if so. This prevents processing of the\nfinal, used descriptor until stmmac_rx_refill() succeeds, but\nfully prevents the `cur_rx == dirty_rx` ambiguity as the previous bugfix\nintended: so remove the clamp as well. Since stmmac_rx_zc() is a\ncopy-paste-and-tweak of stmmac_rx() and the code structure is identical,\nany fix to stmmac_rx() will also need a corresponding fix for\nstmmac_rx_zc(). Therefore, apply the same check there.\n\nIn stmmac_rx() (not stmmac_rx_zc()), a related bug remains: after the\nMAC sets OWN=0 on the final descriptor, it will be unable to send any\nfurther DMA-complete IRQs until it\u0027s given more `empty` descriptors.\nCurrently, the driver simply *hopes* that the next stmmac_rx_refill()\nsucceeds, risking an indefinite stall of the receive process if not. But\nthis is not a regression, so it can be addressed in a future change."
}
],
"id": "CVE-2026-46110",
"lastModified": "2026-06-24T18:28:54.623",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 7.5,
"baseSeverity": "HIGH",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"exploitabilityScore": 3.9,
"impactScore": 3.6,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2026-05-28T10:16:26.420",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/0bb05e6adfa99a2ea1fee1125cc0953409f83ed8"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/4af2e62cbcda575a174acd230c3f3a208135e16d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/5c910f7708e3c507b037ca91ca5b09f8cfe71e65"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/950cb436165aad0f8f2cd49da3cd07677465bcde"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/e1c50b273298c7cd9b08b113e7a7598b531a02f5"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/fdeb95b1fc7de25c9362990efb9996a8d761055c"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Undergoing Analysis",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-476"
}
],
"source": "nvd@nist.gov",
"type": "Primary"
}
]
}
Loading…
Loading…
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
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.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
Loading timeline…
Loading…
Loading…
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.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.