CVE-2026-80555 (GCVE-0-2026-80555)
Vulnerability from cvelistv5
Published
2026-08-26 14:37
Modified
2026-08-27 12:40
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
s390/vfio_ccw: Free all memory if cp_init() fails
The routine cp_free() is called to unpin/free any memory once an I/O
is completed successfully, or if cp_prefetch() fails. But if cp_init()
fails, and cp->initialized is not enabled, the same routine cannot be
used to free all the memory.
An attempt to address this exists in ccwchain_handle_ccw(), where a
single call to ccwchain_free() is made for the currently-processed
CCW segment. But this will leak other segments (created as a result
of a Transfer in Channel) that had been allocated as part of the same
channel program.
Address this by performing the cleanup outside of the recursive
ccwchain_handle_ccw()/ccwchain_loop_tic() logic.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: 8b515be512a2435bb8aedc6390cbe140167f9eb9 Version: 8b515be512a2435bb8aedc6390cbe140167f9eb9 Version: 8b515be512a2435bb8aedc6390cbe140167f9eb9 Version: 8b515be512a2435bb8aedc6390cbe140167f9eb9 Version: 8b515be512a2435bb8aedc6390cbe140167f9eb9 Version: 8b515be512a2435bb8aedc6390cbe140167f9eb9 Version: 8b515be512a2435bb8aedc6390cbe140167f9eb9 Version: 8b515be512a2435bb8aedc6390cbe140167f9eb9 |
||
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/s390/cio/vfio_ccw_cp.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "276bd7ed34d56c48c65c43c0b08f2ee77029b2fa",
"status": "affected",
"version": "8b515be512a2435bb8aedc6390cbe140167f9eb9",
"versionType": "git"
},
{
"lessThan": "f9bcff265556796834122f95de16d52a8375206c",
"status": "affected",
"version": "8b515be512a2435bb8aedc6390cbe140167f9eb9",
"versionType": "git"
},
{
"lessThan": "17e01e342af74de12899c206dcc9ec90684703aa",
"status": "affected",
"version": "8b515be512a2435bb8aedc6390cbe140167f9eb9",
"versionType": "git"
},
{
"lessThan": "152fcb74a26804b70909381c6acc90595a0ae1c1",
"status": "affected",
"version": "8b515be512a2435bb8aedc6390cbe140167f9eb9",
"versionType": "git"
},
{
"lessThan": "6a917199aaf97904f5619afe3dfdacb155b03e8c",
"status": "affected",
"version": "8b515be512a2435bb8aedc6390cbe140167f9eb9",
"versionType": "git"
},
{
"lessThan": "32e3d364a7b8295120d37e6a6bd433d2de26f748",
"status": "affected",
"version": "8b515be512a2435bb8aedc6390cbe140167f9eb9",
"versionType": "git"
},
{
"lessThan": "4699b54fada156534cbb39834d47fc9374d7a1f5",
"status": "affected",
"version": "8b515be512a2435bb8aedc6390cbe140167f9eb9",
"versionType": "git"
},
{
"lessThan": "74186c2968f8f756ac3226b545b598457c910c75",
"status": "affected",
"version": "8b515be512a2435bb8aedc6390cbe140167f9eb9",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/s390/cio/vfio_ccw_cp.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.3"
},
{
"lessThan": "5.3",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.267",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.218",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.185",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.154",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.105",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.46",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.10",
"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": "5.10.267",
"versionStartIncluding": "5.3",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.15.218",
"versionStartIncluding": "5.3",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.1.185",
"versionStartIncluding": "5.3",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.154",
"versionStartIncluding": "5.3",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.105",
"versionStartIncluding": "5.3",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.46",
"versionStartIncluding": "5.3",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.10",
"versionStartIncluding": "5.3",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "5.3",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/vfio_ccw: Free all memory if cp_init() fails\n\nThe routine cp_free() is called to unpin/free any memory once an I/O\nis completed successfully, or if cp_prefetch() fails. But if cp_init()\nfails, and cp-\u003einitialized is not enabled, the same routine cannot be\nused to free all the memory.\n\nAn attempt to address this exists in ccwchain_handle_ccw(), where a\nsingle call to ccwchain_free() is made for the currently-processed\nCCW segment. But this will leak other segments (created as a result\nof a Transfer in Channel) that had been allocated as part of the same\nchannel program.\n\nAddress this by performing the cleanup outside of the recursive\nccwchain_handle_ccw()/ccwchain_loop_tic() logic."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.1,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The bug is reached when userspace writes the vfio-ccw io_region (VFIO device mmap/write), triggering fsm_io_request() -\u003e cp_init(); on s390 KVM this is driven by QEMU forwarding guest channel-I/O channel programs, requiring local VFIO/device interaction rather than any network protocol.\nAC:L - An attacker can deterministically fail cp_init() after allocating multiple TIC-linked ccwchain segments by crafting a channel program whose early TIC targets succeed and a later one fails (invalid CPA, chain-length/count limit, or dma_rw error), leaking prior segments on every attempt without races.\nPR:N - On s390 KVM with CCW passthrough, a malicious guest can submit crafted multi-TIC channel programs through normal guest I/O; QEMU forwards them to vfio-ccw without the attacker holding host CAP_SYS_ADMIN, root, or other real init-namespace privileges beyond the assigned device.\nUI:N - No victim interaction is required beyond the attacker (or their guest) issuing channel-I/O start requests with a malicious channel program; exploitation does not depend on another user mounting media, accepting prompts, or performing administrative actions at trigger time.\nS:C - The leaked ccwchain, CCW, and page_array allocations are host kernel slab memory; a guest VM triggering this through passthrough crosses the guest-host virtualization boundary by consuming host resources the guest security domain should not affect.\nC:N - This is a kernel memory leak on the cp_init() error path, not a use-after-free, out-of-bounds read, or other memory corruption; leaked objects are orphaned in kernel heap and are not returned to userspace or the guest, so no information disclosure occurs.\nI:N - The flaw only fails to free kernel allocations when cp_init() errors; it does not corrupt memory, modify guest or host data, or provide write or control-flow primitives, and cp-\u003einitialized stays false so cp_free() never runs on the error or close paths.\nA:H - Each failed cp_init() permanently orphans up to CCWCHAIN_COUNT_MAX ccwchain segments (large GFP_DMA allocations), and subsequent cp_init() calls INIT_LIST_HEAD without freeing prior leaks; repeated guest or VFIO I/O requests can exhaust host memory and cause system-wide OOM or severe denial of service."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-27T12:40:15.211Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/276bd7ed34d56c48c65c43c0b08f2ee77029b2fa"
},
{
"url": "https://git.kernel.org/stable/c/f9bcff265556796834122f95de16d52a8375206c"
},
{
"url": "https://git.kernel.org/stable/c/17e01e342af74de12899c206dcc9ec90684703aa"
},
{
"url": "https://git.kernel.org/stable/c/152fcb74a26804b70909381c6acc90595a0ae1c1"
},
{
"url": "https://git.kernel.org/stable/c/6a917199aaf97904f5619afe3dfdacb155b03e8c"
},
{
"url": "https://git.kernel.org/stable/c/32e3d364a7b8295120d37e6a6bd433d2de26f748"
},
{
"url": "https://git.kernel.org/stable/c/4699b54fada156534cbb39834d47fc9374d7a1f5"
},
{
"url": "https://git.kernel.org/stable/c/74186c2968f8f756ac3226b545b598457c910c75"
}
],
"title": "s390/vfio_ccw: Free all memory if cp_init() fails",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-80555",
"datePublished": "2026-08-26T14:37:22.969Z",
"dateReserved": "2026-08-26T14:34:25.766Z",
"dateUpdated": "2026-08-27T12:40:15.211Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
Loading…
Loading…
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.
Loading…
Loading…