FKIE_CVE-2026-63964
Vulnerability from fkie_nvd - Published: 2026-07-19 16:17 - Updated: 2026-07-30 14:51
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
usb: typec: ucsi: ccg: reject firmware images without a ':' record header
do_flash() locates the first .cyacd record with
p = strnchr(fw->data, fw->size, ':');
while (p < eof) {
s = strnchr(p + 1, eof - p - 1, ':');
...
}
If the firmware image contains no ':' byte, strnchr() returns NULL.
NULL compares less than the valid kernel pointer eof, so the loop body
runs and strnchr() is called with p + 1 == (void *)1 and a length of
roughly (unsigned long)eof, causing a wonderful crash.
The not_signed_fw fallthrough earlier in do_flash() and the chip-state
branches in ccg_fw_update_needed() allow an unsigned blob to reach this
loop, so a root user who can place a crafted file under /lib/firmware
and write the do_flash sysfs attribute can trigger the oops.
Bail out with -EINVAL when the initial strnchr() returns NULL.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/usb/typec/ucsi/ucsi_ccg.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "b41dfc033fe594e152648050e95b9489cd53e9e3",
"status": "affected",
"version": "5c9ae5a87573d38cfc4c740aafda2fa6ce06e401",
"versionType": "git"
},
{
"lessThan": "2f395ca1263bd181995eb829f5943a83a20db213",
"status": "affected",
"version": "5c9ae5a87573d38cfc4c740aafda2fa6ce06e401",
"versionType": "git"
},
{
"lessThan": "6526f8684f72391138353642af908803ba70795e",
"status": "affected",
"version": "5c9ae5a87573d38cfc4c740aafda2fa6ce06e401",
"versionType": "git"
},
{
"lessThan": "3f432b8203066c26770fe6ea591361f10021dd6b",
"status": "affected",
"version": "5c9ae5a87573d38cfc4c740aafda2fa6ce06e401",
"versionType": "git"
},
{
"lessThan": "c4ee519b06389e59ba2d6aa722fcc4a02a8bbcbb",
"status": "affected",
"version": "5c9ae5a87573d38cfc4c740aafda2fa6ce06e401",
"versionType": "git"
},
{
"lessThan": "a38ed87818b2419090fb1a6338ddce6842b65dfa",
"status": "affected",
"version": "5c9ae5a87573d38cfc4c740aafda2fa6ce06e401",
"versionType": "git"
},
{
"lessThan": "c8460de584fe5415d212cfdd127d4db90835a450",
"status": "affected",
"version": "5c9ae5a87573d38cfc4c740aafda2fa6ce06e401",
"versionType": "git"
},
{
"lessThan": "d7486952bf74e546ee3748fb14b2d07881fa6273",
"status": "affected",
"version": "5c9ae5a87573d38cfc4c740aafda2fa6ce06e401",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/usb/typec/ucsi/ucsi_ccg.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.2"
},
{
"lessThan": "5.2",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.259",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.210",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.176",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.143",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.93",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.35",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.0.*",
"status": "unaffected",
"version": "7.0.12",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nusb: typec: ucsi: ccg: reject firmware images without a \u0027:\u0027 record header\n\ndo_flash() locates the first .cyacd record with\n\n\tp = strnchr(fw-\u003edata, fw-\u003esize, \u0027:\u0027);\n\twhile (p \u003c eof) {\n\t\ts = strnchr(p + 1, eof - p - 1, \u0027:\u0027);\n\t\t...\n\t}\n\nIf the firmware image contains no \u0027:\u0027 byte, strnchr() returns NULL.\nNULL compares less than the valid kernel pointer eof, so the loop body\nruns and strnchr() is called with p + 1 == (void *)1 and a length of\nroughly (unsigned long)eof, causing a wonderful crash.\n\nThe not_signed_fw fallthrough earlier in do_flash() and the chip-state\nbranches in ccg_fw_update_needed() allow an unsigned blob to reach this\nloop, so a root user who can place a crafted file under /lib/firmware\nand write the do_flash sysfs attribute can trigger the oops.\n\nBail out with -EINVAL when the initial strnchr() returns NULL."
}
],
"id": "CVE-2026-63964",
"lastModified": "2026-07-30T14:51:11.223",
"metrics": {},
"published": "2026-07-19T16:17:15.370",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/2f395ca1263bd181995eb829f5943a83a20db213"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/3f432b8203066c26770fe6ea591361f10021dd6b"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/6526f8684f72391138353642af908803ba70795e"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/a38ed87818b2419090fb1a6338ddce6842b65dfa"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/b41dfc033fe594e152648050e95b9489cd53e9e3"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/c4ee519b06389e59ba2d6aa722fcc4a02a8bbcbb"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/c8460de584fe5415d212cfdd127d4db90835a450"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/d7486952bf74e546ee3748fb14b2d07881fa6273"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Awaiting Analysis"
}
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Browse all ATT&CK techniques and the vulnerabilities related to each.
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