CVE-2026-74396 (GCVE-0-2026-74396)
Vulnerability from cvelistv5
Published
2026-08-15 05:59
Modified
2026-08-17 05:46
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
RDMA/mlx5: Fix UMR XLT cleanup on ODP populate failure
mlx5r_umr_update_xlt() allocates and DMA maps an XLT buffer with
mlx5r_umr_create_xlt(). The buffer is released by the common cleanup path
through mlx5r_umr_unmap_free_xlt().
After mlx5_odp_populate_xlt() became fallible, its error path returned
directly and skipped that cleanup. This leaks the XLT DMA mapping and
buffer. If the emergency XLT page was used, it also leaves
xlt_emergency_page_mutex locked.
Break out of the loop so execution falls through the existing cleanup path.
References
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/infiniband/hw/mlx5/umr.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "ffa85a2c197935ace6f1634ad9eb0a44bc615670",
"status": "affected",
"version": "1efe8c0670d6a6883faa09c9abc746c741f5664a",
"versionType": "git"
},
{
"lessThan": "9619909d4869afe720904c6888a289b9ac3055b8",
"status": "affected",
"version": "1efe8c0670d6a6883faa09c9abc746c741f5664a",
"versionType": "git"
},
{
"lessThan": "1eae35b37923cb71b0cb5136d00671440d488b9f",
"status": "affected",
"version": "1efe8c0670d6a6883faa09c9abc746c741f5664a",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/infiniband/hw/mlx5/umr.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.16"
},
{
"lessThan": "6.16",
"status": "unaffected",
"version": "0",
"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"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.40",
"versionStartIncluding": "6.16",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.5",
"versionStartIncluding": "6.16",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "6.16",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/mlx5: Fix UMR XLT cleanup on ODP populate failure\n\nmlx5r_umr_update_xlt() allocates and DMA maps an XLT buffer with\nmlx5r_umr_create_xlt(). The buffer is released by the common cleanup path\nthrough mlx5r_umr_unmap_free_xlt().\n\nAfter mlx5_odp_populate_xlt() became fallible, its error path returned\ndirectly and skipped that cleanup. This leaks the XLT DMA mapping and\nbuffer. If the emergency XLT page was used, it also leaves\nxlt_emergency_page_mutex locked.\n\nBreak out of the loop so execution falls through the existing cleanup path."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.5,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:N - Remote RDMA peers trigger mlx5 ODP hardware page faults over RoCE/InfiniBand (mlx5_ib_mr_rdma_pfault_handler \u2192 pagefault_real_mr \u2192 mlx5r_umr_update_xlt), reaching the buggy cleanup on mlx5 AI/HPC/cloud servers without local syscalls.\nAC:L - An attacker can repeatedly drive ODP page faults, exhaust memory to force the emergency XLT page path, and retry until mlx5_odp_populate_xlt()/hmm_dma_map_pfn() fails; no uncontrollable race or memory layout is required.\nPR:N - The RDMA responder page-fault path executes in kernel workqueues on packets from a connected remote peer and performs no Linux capability or credential check before calling mlx5r_umr_update_xlt().\nUI:N - Exploitation requires only attacker-generated RDMA traffic against exported ODP memory regions once a queue pair exists; no additional victim action beyond normal RDMA service operation is needed.\nS:U - The DMA mapping leak and permanent xlt_emergency_page_mutex lock affect mlx5 driver resources within the same host kernel security authority; there is no VM escape or IOMMU-boundary bypass.\nC:N - The bug skips unmap/free of an XLT translation buffer; it does not corrupt memory, dereference freed objects, or provide an arbitrary kernel read primitive.\nI:N - No out-of-bounds write, use-after-free, or control-flow corruption occurs; the defect only leaks resources rather than enabling arbitrary data modification.\nA:H - Each failure leaks a DMA mapping and buffer, and on the emergency-page path permanently locks xlt_emergency_page_mutex, deadlocking subsequent UMR XLT updates and disabling ODP/RDMA on the mlx5 device."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-17T05:46:40.931Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/ffa85a2c197935ace6f1634ad9eb0a44bc615670"
},
{
"url": "https://git.kernel.org/stable/c/9619909d4869afe720904c6888a289b9ac3055b8"
},
{
"url": "https://git.kernel.org/stable/c/1eae35b37923cb71b0cb5136d00671440d488b9f"
}
],
"title": "RDMA/mlx5: Fix UMR XLT cleanup on ODP populate failure",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-74396",
"datePublished": "2026-08-15T05:59:08.694Z",
"dateReserved": "2026-08-15T05:44:03.891Z",
"dateUpdated": "2026-08-17T05:46:40.931Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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