{
    "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": "2026-08-05T12:11:53.356Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-05T12:11:53.356Z"
            },
            "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": "e5bf5ee266633cb18fff6f98f0b7d59a62819eee",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "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": "6.19",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "2.6.35",
                                    "versionEndExcluding": "6.19"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/e5bf5ee266633cb18fff6f98f0b7d59a62819eee"
                }
            ],
            "title": "functionfs: fix the open/removal races",
            "x_generator": {
                "engine": "bippy-1.2.0"
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    }
}