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vuln-cve/data/2025/71xxx/CVE-2025-71074.json
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{
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"cveMetadata": {
"cveId": "CVE-2025-71074",
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"state": "PUBLISHED",
"assignerShortName": "Linux",
"dateReserved": "2026-01-13T15:30:19.647Z",
"datePublished": "2026-01-13T15:31:27.413Z",
"dateUpdated": "2026-10-30T12:23:24.377Z"
},
"containers": {
"cna": {
"providerMetadata": {
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux",
"dateUpdated": "2026-10-30T12:23:24.377Z"
},
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfunctionfs: fix the open/removal races\n\nffs_epfile_open() can race with removal, ending up with file->private_data\npointing to freed object.\n\nThere is a total count of opened files on functionfs (both ep0 and\ndynamic ones) and when it hits zero, dynamic files get removed.\nUnfortunately, that removal can happen while another thread is\nin ffs_epfile_open(), but has not incremented the count yet.\nIn that case open will succeed, leaving us with UAF on any subsequent\nread() or write().\n\nThe root cause is that ffs->opened is misused; atomic_dec_and_test() vs.\natomic_add_return() is not a good idea, when object remains visible all\nalong.\n\nTo untangle that\n\t* serialize openers on ffs->mutex (both for ep0 and for dynamic files)\n\t* have dynamic ones use atomic_inc_not_zero() and fail if we had\nzero ->opened; in that case the file we are opening is doomed.\n\t* have the inodes of dynamic files marked on removal (from the\ncallback of simple_recursive_removal()) - clear ->i_private there.\n\t* have open of dynamic ones verify they hadn't been already removed,\nalong with checking that state is FFS_ACTIVE."
}
],
"metrics": [
{
"cvssV3_1": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"baseScore": 7.8,
"baseSeverity": "HIGH"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The race is reached through local open, close, read, write, or ioctl operations on FunctionFS endpoint files. A USB host cannot directly invoke ffs_epfile_open(), so this is local rather than physical or network access.\nAC:L - The attacker can race opening a dynamic endpoint against closing the sole remaining ep0 descriptor and repeat the attempt with controlled threads. Both race sides and the freed allocation's endpoint-controlled size are attacker-controlled.\nPR:L - Mounting FunctionFS requires CAP_SYS_ADMIN in the initial user namespace, but endpoint opening has no capability check and uid/gid/fmode options permit delegation to non-root service accounts, as in [AOSP FunctionFS mounts](https://android.googlesource.com/device/google/gs201/%2B/587 5d29f/conf/init.gs201.usb.rc). A low-privileged local account with delegated endpoint access can therefore trigger the race.\nUI:N - The attacker independently performs endpoint configuration, concurrent open and close operations, and subsequent use of the stale descriptor without victim interaction.\nS:U - Exploitation corrupts memory within the kernel's existing security authority and constitutes ordinary local kernel compromise rather than crossing a VM or IOMMU boundary.\nC:H - The attacker-sized heap object contains numerous pointers and can be reclaimed before stale read, ioctl, or release operations, making kernel-memory disclosure through the UAF defensible.\nI:H - The stale object reaches mutex and list operations, atomic modification, xchg and kfree operations, and USB request handling, providing plausible arbitrary-write, arbitrary-free, and control-flow-hijacking primitives.\nA:H - Dereferencing the freed object, locking reclaimed mutexes, freeing attacker-influenced pointers, or triggering warnings under panic-on-warn can crash or panic the kernel."
}
]
}
],
"affected": [
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "unaffected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"drivers/usb/gadget/function/f_fs.c"
],
"versions": [
{
"version": "ddf8abd2599491cbad959c700b90ba72a5dce8d0",
"lessThan": "e002b3c1e6a0faa53329ef0d21e6351bcece6edb",
"status": "affected",
"versionType": "git"
},
{
"version": "ddf8abd2599491cbad959c700b90ba72a5dce8d0",
"lessThan": "585a656283c954337036422afcd9cb70dd4135e7",
"status": "affected",
"versionType": "git"
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{
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"lessThan": "75240e5e51c6e6d67a3039384125fa54259a3926",
"status": "affected",
"versionType": "git"
},
{
"version": "ddf8abd2599491cbad959c700b90ba72a5dce8d0",
"lessThan": "e5bf5ee266633cb18fff6f98f0b7d59a62819eee",
"status": "affected",
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},
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "affected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"drivers/usb/gadget/function/f_fs.c"
],
"versions": [
{
"version": "2.6.35",
"status": "affected"
},
{
"version": "0",
"lessThan": "2.6.35",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "6.1.191",
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "6.6.160",
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "6.12.114",
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "6.19",
"lessThanOrEqual": "*",
"status": "unaffected",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"operator": "OR",
"negate": false,
"cpeMatch": [
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"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "2.6.35",
"versionEndExcluding": "6.1.191"
},
{
"vulnerable": true,
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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"references": [
{
"url": "https://git.kernel.org/stable/c/e002b3c1e6a0faa53329ef0d21e6351bcece6edb"
},
{
"url": "https://git.kernel.org/stable/c/585a656283c954337036422afcd9cb70dd4135e7"
},
{
"url": "https://git.kernel.org/stable/c/75240e5e51c6e6d67a3039384125fa54259a3926"
},
{
"url": "https://git.kernel.org/stable/c/e5bf5ee266633cb18fff6f98f0b7d59a62819eee"
}
],
"title": "functionfs: fix the open/removal races",
"x_generator": {
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