Vulnerability-Lookup

CVE-2026-64456 (GCVE-0-2026-64456)

Vulnerability from cvelistv5 – Published: 2026-07-25 08:51 – Updated: 2026-07-25 08:51

Title

hwrng: virtio: clamp device-reported used.len at copy_data()

Summary

In the Linux kernel, the following vulnerability has been resolved: hwrng: virtio: clamp device-reported used.len at copy_data() random_recv_done() stores the device-reported used.len directly into vi->data_avail. copy_data() then indexes vi->data[] using vi->data_idx (advanced by previous copy_data() calls) and issues a memcpy() without re-validating either value against the posted buffer size sizeof(vi->data) (SMP_CACHE_BYTES bytes, typically 32 or 64). A malicious or buggy virtio-rng backend can set used.len beyond sizeof(vi->data), steering the memcpy() past the end of the inline array into adjacent kmalloc-1k slab bytes. hwrng_fillfn() mixes those bytes into the guest RNG, and guest root can also observe them directly via /dev/hwrng. Concrete impact is inside the guest: - Memory-safety / hardening: any virtio-rng backend that over-reports used.len causes the driver to read past vi->data into unrelated slab contents. hwrng_fillfn() is a kernel thread that runs as soon as the device is probed; no guest userspace interaction is required to first-trigger the OOB. - Cross-boundary leak (confidential-compute threat model): a malicious hypervisor cooperating with a malicious or compromised guest root userspace can use /dev/hwrng as a leak channel for guest-kernel heap data. The host sets a large used.len, guest root reads /dev/hwrng, and the returned bytes contain guest kernel slab contents that were adjacent to vi->data. In practice, confidential-compute guests (SEV-SNP, TDX) usually disable virtio-rng entirely, so this path is narrow, but the fix is still worth carrying because the underlying memory-safety bug contaminates the guest RNG on any host. KASAN confirms the OOB on a 7.1-rc4 guest whose virtio-rng backend has been patched to report used.len = 0x10000: BUG: KASAN: slab-out-of-bounds in virtio_read+0x394/0x5d0 Read of size 64 at addr ffff88800ae0ba20 by task hwrng/52 Call Trace: __asan_memcpy+0x23/0x60 virtio_read+0x394/0x5d0 hwrng_fillfn+0xb2/0x470 kthread+0x2cc/0x3a0 Allocated by task 1: probe_common+0xa5/0x660 virtio_dev_probe+0x549/0xbc0 The buggy address belongs to the object at ffff88800ae0b800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 0 bytes to the right of allocated 544-byte region [ffff88800ae0b800, ffff88800ae0ba20) Same class of bug as commit c04db81cd028 ("net/9p: Fix buffer overflow in USB transport layer"), which hardened usb9pfs_rx_complete() against unchecked device-reported length in the USB 9p transport. With the clamp at point of use and array_index_nospec() in place, the same harness boots cleanly: copy_data() returns zero for the bogus report, the device-supplied bytes after data_idx are discarded, and the driver issues a fresh request.

Severity

No CVSS data available.

Assigner

Linux

References

8 references

URL	Tags
https://git.kernel.org/stable/c/3aa3e89cf80721c8d…
https://git.kernel.org/stable/c/63335e7b638ae7002…
https://git.kernel.org/stable/c/2e788948ff2a13358…
https://git.kernel.org/stable/c/fde19b0d4eeabae04…
https://git.kernel.org/stable/c/81dd21b5f0c299cc7…
https://git.kernel.org/stable/c/285e17c44e3873a73…
https://git.kernel.org/stable/c/92d5736a62040ec1c…
https://git.kernel.org/stable/c/e3046eeada299f917…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: f7f510ec195781c857ab76366a3e1c59e1caae42 , < 3aa3e89cf80721c8d382b4c1a2b70a0449dad4a5 (git) Affected: f7f510ec195781c857ab76366a3e1c59e1caae42 , < 63335e7b638ae70028ae285bb95153874a8bc852 (git) Affected: f7f510ec195781c857ab76366a3e1c59e1caae42 , < 2e788948ff2a13358a303af112497a63201c5739 (git) Affected: f7f510ec195781c857ab76366a3e1c59e1caae42 , < fde19b0d4eeabae042519313c843fe6f27d41e9d (git) Affected: f7f510ec195781c857ab76366a3e1c59e1caae42 , < 81dd21b5f0c299cc7b5bf84f04a61938559d20e6 (git) Affected: f7f510ec195781c857ab76366a3e1c59e1caae42 , < 285e17c44e3873a73460f294acbd64018ff64385 (git) Affected: f7f510ec195781c857ab76366a3e1c59e1caae42 , < 92d5736a62040ec1cfff23ea57e6599301690ad5 (git) Affected: f7f510ec195781c857ab76366a3e1c59e1caae42 , < e3046eeada299f917a8ad883af4434bfb86556b1 (git)
Linux	Linux	Affected: 2.6.26 Unaffected: 0 , < 2.6.26 (semver) Unaffected: 5.10.261 , ≤ 5.10.* (semver) Unaffected: 5.15.212 , ≤ 5.15.* (semver) Unaffected: 6.1.178 , ≤ 6.1.* (semver) Unaffected: 6.6.145 , ≤ 6.6.* (semver) Unaffected: 6.12.96 , ≤ 6.12.* (semver) Unaffected: 6.18.39 , ≤ 6.18.* (semver) Unaffected: 7.1.4 , ≤ 7.1.* (semver) Unaffected: 7.2-rc1 , ≤ * (original_commit_for_fix)

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              "status": "unaffected",
              "version": "5.15.212",
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              "status": "unaffected",
              "version": "6.12.96",
              "versionType": "semver"
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              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
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              "status": "unaffected",
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nhwrng: virtio: clamp device-reported used.len at copy_data()\n\nrandom_recv_done() stores the device-reported used.len directly into\nvi-\u003edata_avail.  copy_data() then indexes vi-\u003edata[] using\nvi-\u003edata_idx (advanced by previous copy_data() calls) and issues a\nmemcpy() without re-validating either value against the posted\nbuffer size sizeof(vi-\u003edata) (SMP_CACHE_BYTES bytes, typically 32\nor 64).\n\nA malicious or buggy virtio-rng backend can set used.len beyond\nsizeof(vi-\u003edata), steering the memcpy() past the end of the inline\narray into adjacent kmalloc-1k slab bytes.  hwrng_fillfn() mixes\nthose bytes into the guest RNG, and guest root can also observe\nthem directly via /dev/hwrng.\n\nConcrete impact is inside the guest:\n\n - Memory-safety / hardening: any virtio-rng backend that\n   over-reports used.len causes the driver to read past vi-\u003edata\n   into unrelated slab contents.  hwrng_fillfn() is a kernel thread\n   that runs as soon as the device is probed; no guest userspace\n   interaction is required to first-trigger the OOB.\n\n - Cross-boundary leak (confidential-compute threat model): a\n   malicious hypervisor cooperating with a malicious or compromised\n   guest root userspace can use /dev/hwrng as a leak channel for\n   guest-kernel heap data.  The host sets a large used.len, guest\n   root reads /dev/hwrng, and the returned bytes contain guest\n   kernel slab contents that were adjacent to vi-\u003edata.  In\n   practice, confidential-compute guests (SEV-SNP, TDX) usually\n   disable virtio-rng entirely, so this path is narrow, but the\n   fix is still worth carrying because the underlying\n   memory-safety bug contaminates the guest RNG on any host.\n\nKASAN confirms the OOB on a 7.1-rc4 guest whose virtio-rng backend\nhas been patched to report used.len = 0x10000:\n\n  BUG: KASAN: slab-out-of-bounds in virtio_read+0x394/0x5d0\n  Read of size 64 at addr ffff88800ae0ba20 by task hwrng/52\n  Call Trace:\n   __asan_memcpy+0x23/0x60\n   virtio_read+0x394/0x5d0\n   hwrng_fillfn+0xb2/0x470\n   kthread+0x2cc/0x3a0\n  Allocated by task 1:\n   probe_common+0xa5/0x660\n   virtio_dev_probe+0x549/0xbc0\n  The buggy address belongs to the object at ffff88800ae0b800\n   which belongs to the cache kmalloc-1k of size 1024\n  The buggy address is located 0 bytes to the right of\n   allocated 544-byte region [ffff88800ae0b800, ffff88800ae0ba20)\n\nSame class of bug as commit c04db81cd028 (\"net/9p: Fix buffer\noverflow in USB transport layer\"), which hardened\nusb9pfs_rx_complete() against unchecked device-reported length in\nthe USB 9p transport.\n\nWith the clamp at point of use and array_index_nospec() in place,\nthe same harness boots cleanly: copy_data() returns zero for the\nbogus report, the device-supplied bytes after data_idx are\ndiscarded, and the driver issues a fresh request."
        }
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      ],
      "title": "hwrng: virtio: clamp device-reported used.len at copy_data()",
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    "cveId": "CVE-2026-64456",
    "datePublished": "2026-07-25T08:51:24.659Z",
    "dateReserved": "2026-07-19T15:36:31.789Z",
    "dateUpdated": "2026-07-25T08:51:24.659Z",
    "state": "PUBLISHED"
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    "nvd": "{\"cve\":{\"id\":\"CVE-2026-64456\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-07-25T10:17:30.677\",\"lastModified\":\"2026-07-25T10:17:30.677\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nhwrng: virtio: clamp device-reported used.len at copy_data()\\n\\nrandom_recv_done() stores the device-reported used.len directly into\\nvi-\u003edata_avail.  copy_data() then indexes vi-\u003edata[] using\\nvi-\u003edata_idx (advanced by previous copy_data() calls) and issues a\\nmemcpy() without re-validating either value against the posted\\nbuffer size sizeof(vi-\u003edata) (SMP_CACHE_BYTES bytes, typically 32\\nor 64).\\n\\nA malicious or buggy virtio-rng backend can set used.len beyond\\nsizeof(vi-\u003edata), steering the memcpy() past the end of the inline\\narray into adjacent kmalloc-1k slab bytes.  hwrng_fillfn() mixes\\nthose bytes into the guest RNG, and guest root can also observe\\nthem directly via /dev/hwrng.\\n\\nConcrete impact is inside the guest:\\n\\n - Memory-safety / hardening: any virtio-rng backend that\\n   over-reports used.len causes the driver to read past vi-\u003edata\\n   into unrelated slab contents.  hwrng_fillfn() is a kernel thread\\n   that runs as soon as the device is probed; no guest userspace\\n   interaction is required to first-trigger the OOB.\\n\\n - Cross-boundary leak (confidential-compute threat model): a\\n   malicious hypervisor cooperating with a malicious or compromised\\n   guest root userspace can use /dev/hwrng as a leak channel for\\n   guest-kernel heap data.  The host sets a large used.len, guest\\n   root reads /dev/hwrng, and the returned bytes contain guest\\n   kernel slab contents that were adjacent to vi-\u003edata.  In\\n   practice, confidential-compute guests (SEV-SNP, TDX) usually\\n   disable virtio-rng entirely, so this path is narrow, but the\\n   fix is still worth carrying because the underlying\\n   memory-safety bug contaminates the guest RNG on any host.\\n\\nKASAN confirms the OOB on a 7.1-rc4 guest whose virtio-rng backend\\nhas been patched to report used.len = 0x10000:\\n\\n  BUG: KASAN: slab-out-of-bounds in virtio_read+0x394/0x5d0\\n  Read of size 64 at addr ffff88800ae0ba20 by task hwrng/52\\n  Call Trace:\\n   __asan_memcpy+0x23/0x60\\n   virtio_read+0x394/0x5d0\\n   hwrng_fillfn+0xb2/0x470\\n   kthread+0x2cc/0x3a0\\n  Allocated by task 1:\\n   probe_common+0xa5/0x660\\n   virtio_dev_probe+0x549/0xbc0\\n  The buggy address belongs to the object at ffff88800ae0b800\\n   which belongs to the cache kmalloc-1k of size 1024\\n  The buggy address is located 0 bytes to the right of\\n   allocated 544-byte region [ffff88800ae0b800, ffff88800ae0ba20)\\n\\nSame class of bug as commit c04db81cd028 (\\\"net/9p: Fix buffer\\noverflow in USB transport layer\\\"), which hardened\\nusb9pfs_rx_complete() against unchecked device-reported length in\\nthe USB 9p transport.\\n\\nWith the clamp at point of use and array_index_nospec() in place,\\nthe same harness boots cleanly: copy_data() returns zero for the\\nbogus report, the device-supplied bytes after data_idx are\\ndiscarded, and the driver issues a fresh request.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"drivers/char/hw_random/virtio-rng.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"f7f510ec195781c857ab76366a3e1c59e1caae42\",\"lessThan\":\"3aa3e89cf80721c8d382b4c1a2b70a0449dad4a5\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"f7f510ec195781c857ab76366a3e1c59e1caae42\",\"lessThan\":\"63335e7b638ae70028ae285bb95153874a8bc852\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"f7f510ec195781c857ab76366a3e1c59e1caae42\",\"lessThan\":\"2e788948ff2a13358a303af112497a63201c5739\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"f7f510ec195781c857ab76366a3e1c59e1caae42\",\"lessThan\":\"fde19b0d4eeabae042519313c843fe6f27d41e9d\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"f7f510ec195781c857ab76366a3e1c59e1caae42\",\"lessThan\":\"81dd21b5f0c299cc7b5bf84f04a61938559d20e6\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"f7f510ec195781c857ab76366a3e1c59e1caae42\",\"lessThan\":\"285e17c44e3873a73460f294acbd64018ff64385\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"f7f510ec195781c857ab76366a3e1c59e1caae42\",\"lessThan\":\"92d5736a62040ec1cfff23ea57e6599301690ad5\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"f7f510ec195781c857ab76366a3e1c59e1caae42\",\"lessThan\":\"e3046eeada299f917a8ad883af4434bfb86556b1\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"drivers/char/hw_random/virtio-rng.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"2.6.26\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"2.6.26\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.10.261\",\"lessThanOrEqual\":\"5.10.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.212\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.178\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.145\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.96\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.39\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.4\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2-rc1\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/285e17c44e3873a73460f294acbd64018ff64385\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/2e788948ff2a13358a303af112497a63201c5739\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/3aa3e89cf80721c8d382b4c1a2b70a0449dad4a5\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/63335e7b638ae70028ae285bb95153874a8bc852\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/81dd21b5f0c299cc7b5bf84f04a61938559d20e6\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/92d5736a62040ec1cfff23ea57e6599301690ad5\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/e3046eeada299f917a8ad883af4434bfb86556b1\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/fde19b0d4eeabae042519313c843fe6f27d41e9d\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "suse_vex": {
      "aggregate_severity": "not set",
      "current_release_date": "2026-07-25T15:58:58Z",
      "cve": "CVE-2026-64456",
      "id": "CVE-2026-64456",
      "initial_release_date": "2026-07-25T15:58:58Z",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-64456",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-64456.json",
      "version": "2"
    }
  }
}

GHSA-7VRC-RFF8-P548

Vulnerability from github – Published: 2026-07-25 12:31 – Updated: 2026-07-25 12:31

Details

In the Linux kernel, the following vulnerability has been resolved:

hwrng: virtio: clamp device-reported used.len at copy_data()

random_recv_done() stores the device-reported used.len directly into vi->data_avail. copy_data() then indexes vi->data[] using vi->data_idx (advanced by previous copy_data() calls) and issues a memcpy() without re-validating either value against the posted buffer size sizeof(vi->data) (SMP_CACHE_BYTES bytes, typically 32 or 64).

A malicious or buggy virtio-rng backend can set used.len beyond sizeof(vi->data), steering the memcpy() past the end of the inline array into adjacent kmalloc-1k slab bytes. hwrng_fillfn() mixes those bytes into the guest RNG, and guest root can also observe them directly via /dev/hwrng.

Concrete impact is inside the guest:

Memory-safety / hardening: any virtio-rng backend that over-reports used.len causes the driver to read past vi->data into unrelated slab contents. hwrng_fillfn() is a kernel thread that runs as soon as the device is probed; no guest userspace interaction is required to first-trigger the OOB.
Cross-boundary leak (confidential-compute threat model): a malicious hypervisor cooperating with a malicious or compromised guest root userspace can use /dev/hwrng as a leak channel for guest-kernel heap data. The host sets a large used.len, guest root reads /dev/hwrng, and the returned bytes contain guest kernel slab contents that were adjacent to vi->data. In practice, confidential-compute guests (SEV-SNP, TDX) usually disable virtio-rng entirely, so this path is narrow, but the fix is still worth carrying because the underlying memory-safety bug contaminates the guest RNG on any host.

KASAN confirms the OOB on a 7.1-rc4 guest whose virtio-rng backend has been patched to report used.len = 0x10000:

BUG: KASAN: slab-out-of-bounds in virtio_read+0x394/0x5d0 Read of size 64 at addr ffff88800ae0ba20 by task hwrng/52 Call Trace: __asan_memcpy+0x23/0x60 virtio_read+0x394/0x5d0 hwrng_fillfn+0xb2/0x470 kthread+0x2cc/0x3a0 Allocated by task 1: probe_common+0xa5/0x660 virtio_dev_probe+0x549/0xbc0 The buggy address belongs to the object at ffff88800ae0b800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 0 bytes to the right of allocated 544-byte region [ffff88800ae0b800, ffff88800ae0ba20)

Same class of bug as commit c04db81cd028 ("net/9p: Fix buffer overflow in USB transport layer"), which hardened usb9pfs_rx_complete() against unchecked device-reported length in the USB 9p transport.

With the clamp at point of use and array_index_nospec() in place, the same harness boots cleanly: copy_data() returns zero for the bogus report, the device-supplied bytes after data_idx are discarded, and the driver issues a fresh request.

Show details on source website

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{
  "affected": [],
  "aliases": [
    "CVE-2026-64456"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-25T10:17:30Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nhwrng: virtio: clamp device-reported used.len at copy_data()\n\nrandom_recv_done() stores the device-reported used.len directly into\nvi-\u003edata_avail.  copy_data() then indexes vi-\u003edata[] using\nvi-\u003edata_idx (advanced by previous copy_data() calls) and issues a\nmemcpy() without re-validating either value against the posted\nbuffer size sizeof(vi-\u003edata) (SMP_CACHE_BYTES bytes, typically 32\nor 64).\n\nA malicious or buggy virtio-rng backend can set used.len beyond\nsizeof(vi-\u003edata), steering the memcpy() past the end of the inline\narray into adjacent kmalloc-1k slab bytes.  hwrng_fillfn() mixes\nthose bytes into the guest RNG, and guest root can also observe\nthem directly via /dev/hwrng.\n\nConcrete impact is inside the guest:\n\n - Memory-safety / hardening: any virtio-rng backend that\n   over-reports used.len causes the driver to read past vi-\u003edata\n   into unrelated slab contents.  hwrng_fillfn() is a kernel thread\n   that runs as soon as the device is probed; no guest userspace\n   interaction is required to first-trigger the OOB.\n\n - Cross-boundary leak (confidential-compute threat model): a\n   malicious hypervisor cooperating with a malicious or compromised\n   guest root userspace can use /dev/hwrng as a leak channel for\n   guest-kernel heap data.  The host sets a large used.len, guest\n   root reads /dev/hwrng, and the returned bytes contain guest\n   kernel slab contents that were adjacent to vi-\u003edata.  In\n   practice, confidential-compute guests (SEV-SNP, TDX) usually\n   disable virtio-rng entirely, so this path is narrow, but the\n   fix is still worth carrying because the underlying\n   memory-safety bug contaminates the guest RNG on any host.\n\nKASAN confirms the OOB on a 7.1-rc4 guest whose virtio-rng backend\nhas been patched to report used.len = 0x10000:\n\n  BUG: KASAN: slab-out-of-bounds in virtio_read+0x394/0x5d0\n  Read of size 64 at addr ffff88800ae0ba20 by task hwrng/52\n  Call Trace:\n   __asan_memcpy+0x23/0x60\n   virtio_read+0x394/0x5d0\n   hwrng_fillfn+0xb2/0x470\n   kthread+0x2cc/0x3a0\n  Allocated by task 1:\n   probe_common+0xa5/0x660\n   virtio_dev_probe+0x549/0xbc0\n  The buggy address belongs to the object at ffff88800ae0b800\n   which belongs to the cache kmalloc-1k of size 1024\n  The buggy address is located 0 bytes to the right of\n   allocated 544-byte region [ffff88800ae0b800, ffff88800ae0ba20)\n\nSame class of bug as commit c04db81cd028 (\"net/9p: Fix buffer\noverflow in USB transport layer\"), which hardened\nusb9pfs_rx_complete() against unchecked device-reported length in\nthe USB 9p transport.\n\nWith the clamp at point of use and array_index_nospec() in place,\nthe same harness boots cleanly: copy_data() returns zero for the\nbogus report, the device-supplied bytes after data_idx are\ndiscarded, and the driver issues a fresh request.",
  "id": "GHSA-7vrc-rff8-p548",
  "modified": "2026-07-25T12:31:36Z",
  "published": "2026-07-25T12:31:36Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64456"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/285e17c44e3873a73460f294acbd64018ff64385"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2e788948ff2a13358a303af112497a63201c5739"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3aa3e89cf80721c8d382b4c1a2b70a0449dad4a5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/63335e7b638ae70028ae285bb95153874a8bc852"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/81dd21b5f0c299cc7b5bf84f04a61938559d20e6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/92d5736a62040ec1cfff23ea57e6599301690ad5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e3046eeada299f917a8ad883af4434bfb86556b1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fde19b0d4eeabae042519313c843fe6f27d41e9d"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

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.

Detection rules are retrieved from Rulezet.

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.

Action not permitted

CVE-2026-64456 (GCVE-0-2026-64456)

GHSA-7VRC-RFF8-P548

Tags

Sightings

Nomenclature