CVE-2026-74712 (GCVE-0-2026-74712)
Vulnerability from cvelistv5
Published
2026-08-22 15:33
Modified
2026-08-25 05:41
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
vdpa/mlx5: Fix buffer length in create_direct_keys()
We have seen in our CI the following KASAN message:
BUG: KASAN: slab-out-of-bounds in cmd_exec+0x550/0xca0 [mlx5_core]
Read of size 272 at addr 0000000176795020 by task qemu-system-s39/82764
[...]
[<000011388ab3a7a0>] cmd_exec+0x550/0xca0 [mlx5_core]
[<000011388ab3b61c>] mlx5_cmd_exec_cb+0x25c/0x4f0 [mlx5_core]
[<000011388b21e82e>] mlx5_vdpa_exec_async_cmds+0x22e/0x5e0 [mlx5_vdpa]
[<000011388b21fd44>] create_direct_keys+0x954/0xef0 [mlx5_vdpa]
[...]
The buggy address is located 4128 bytes inside of
allocated 4384-byte region [0000000176794000, 0000000176795120)
So in essence we read 16 bytes beyond 4384-byte allocation.
create_direct_keys calculates the pointer and length for in and out
buffers.
The size calculation for in includes the entire structure
size (out + in + mtt[]) but the pointer passed to cmd_exec points only
to the 'in' field, skipping the 'out' field.
This causes mlx5_copy_to_msg() to read beyond the allocated buffer
by sizeof(out) bytes when copying command data.
Properly calculate the input size to match the pointer and allocation size.
References
| URL | Tags | |
|---|---|---|
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/vdpa/mlx5/core/mr.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "ec3bb289cf19d526224117d5d450a5fd9cbd5ab2",
"status": "affected",
"version": "0071b138d44af4296bf871e6624369ce697b4b15",
"versionType": "git"
},
{
"lessThan": "cde8931a25392670dd59a0acfcab87a830ab66c5",
"status": "affected",
"version": "0071b138d44af4296bf871e6624369ce697b4b15",
"versionType": "git"
},
{
"lessThan": "6c8a9f7bc00301e533a5366384f3070a8e7f8430",
"status": "affected",
"version": "0071b138d44af4296bf871e6624369ce697b4b15",
"versionType": "git"
},
{
"lessThan": "727e1f569855df83579edbd73dcb4a0723543a12",
"status": "affected",
"version": "0071b138d44af4296bf871e6624369ce697b4b15",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/vdpa/mlx5/core/mr.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.12"
},
{
"lessThan": "6.12",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.104",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.45",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.9",
"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": "6.12.104",
"versionStartIncluding": "6.12",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.45",
"versionStartIncluding": "6.12",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.9",
"versionStartIncluding": "6.12",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "6.12",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvdpa/mlx5: Fix buffer length in create_direct_keys()\n\nWe have seen in our CI the following KASAN message:\nBUG: KASAN: slab-out-of-bounds in cmd_exec+0x550/0xca0 [mlx5_core]\nRead of size 272 at addr 0000000176795020 by task qemu-system-s39/82764\n[...]\n[\u003c000011388ab3a7a0\u003e] cmd_exec+0x550/0xca0 [mlx5_core]\n[\u003c000011388ab3b61c\u003e] mlx5_cmd_exec_cb+0x25c/0x4f0 [mlx5_core]\n[\u003c000011388b21e82e\u003e] mlx5_vdpa_exec_async_cmds+0x22e/0x5e0 [mlx5_vdpa]\n[\u003c000011388b21fd44\u003e] create_direct_keys+0x954/0xef0 [mlx5_vdpa]\n[...]\nThe buggy address is located 4128 bytes inside of\nallocated 4384-byte region [0000000176794000, 0000000176795120)\n\nSo in essence we read 16 bytes beyond 4384-byte allocation.\ncreate_direct_keys calculates the pointer and length for in and out\nbuffers.\nThe size calculation for in includes the entire structure\nsize (out + in + mtt[]) but the pointer passed to cmd_exec points only\nto the \u0027in\u0027 field, skipping the \u0027out\u0027 field.\n\nThis causes mlx5_copy_to_msg() to read beyond the allocated buffer\nby sizeof(out) bytes when copying command data.\n\nProperly calculate the input size to match the pointer and allocation size."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 9.3,
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The bug is reached when host vDPA memory keys are created during IOTLB/set_map handling on /dev/vhost-vdpa (ioctl/write from QEMU/vhost), not from remote network packet processing; worst case is a co-tenant VM guest driving host QEMU virtio memory updates on the same mlx5 vDPA host.\nAC:L - Once mlx5 vDPA user MR setup runs, create_direct_keys() always passes an oversized inlen to mlx5_cmd_exec_cb(), deterministically causing mlx5_copy_to_msg() to read past the slab allocation; no race or victim state is required beyond normal virtio memory mapping.\nPR:N - In cloud mlx5 virtio-vDPA deployments a malicious VM tenant needs no host credentials\u2014normal guest virtio-net bring-up causes QEMU to issue vhost IOTLB updates that invoke mlx5_vdpa_set_map() and create_user_mr() on the host without CAP_NET_ADMIN or root in the host init namespace.\nUI:N - Exploitation requires only automated virtio driver initialization and memory table updates; no additional victim clicks, mounts, or manual actions are needed beyond provisioning a vDPA-backed VM, which is the intended operational path.\nS:C - The vulnerable mlx5 vDPA code runs in the hypervisor host kernel while the practical attacker is a guest VM tenant; successful slab out-of-bounds reads and corrupted firmware commands cross the guest/host virtualization boundary per KVM guest-to-host guidance.\nC:H - Incorrect inlen makes mlx5_copy_to_msg() perform a slab out-of-bounds read (KASAN-reported) of adjacent kernel heap memory, copying leaked bytes into CREATE_MKEY commands and enabling arbitrary kernel information disclosure, not a bounded benign leak.\nI:H - The over-read injects adjacent heap contents into firmware CREATE_MKEY command buffers, corrupting memory-key setup data sent to the mlx5 device; this is exploitable kernel memory corruption that can alter device DMA mappings and enable further control, not a read-only crash.\nA:H - The flaw triggers a KASAN slab-out-of-bounds fault in mlx5_core cmd_exec() during normal MR creation; such heap corruption commonly causes kernel oops/panic and can also destabilize vDPA networking on repeated virtio memory remaps."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-25T05:41:54.897Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/ec3bb289cf19d526224117d5d450a5fd9cbd5ab2"
},
{
"url": "https://git.kernel.org/stable/c/cde8931a25392670dd59a0acfcab87a830ab66c5"
},
{
"url": "https://git.kernel.org/stable/c/6c8a9f7bc00301e533a5366384f3070a8e7f8430"
},
{
"url": "https://git.kernel.org/stable/c/727e1f569855df83579edbd73dcb4a0723543a12"
}
],
"title": "vdpa/mlx5: Fix buffer length in create_direct_keys()",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-74712",
"datePublished": "2026-08-22T15:33:08.392Z",
"dateReserved": "2026-08-15T05:44:03.928Z",
"dateUpdated": "2026-08-25T05:41:54.897Z",
"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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