{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-90045", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.783Z", "datePublished": "2026-09-16T10:33:42.411Z", "dateUpdated": "2026-10-21T12:49:37.631Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-21T12:49:37.631Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nUSB: gadget: ffs: fix mm lifetime handling\n\nio_data stores a pointer to the submitting task's mm_struct,\nbut does not currently hold a reference to it while async\nrequests are pending.\n\nThis can result in a use-after-free if the task exits before\ncompletion handling finishes.\n\nTake a reference with mmgrab() when queuing the read request\nand release it with mmdrop() on request completion." } ], "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 UAF is reached via local aio_read/io_submit on FunctionFS ep files (ffs_epfile_read_iter → ffs_epfile_io), not by parsing USB host packets. This is the gadget userspace API; prior f_fs AIO UAFs (CVE-2024-36894, CVE-2025-71074) are scored Local, which is also the higher-severity vector versus Physical.\nAC:L - The attacker submits the AIO read, can complete it locally (dummy_hcd or an already-bound gadget) and exit while the ordered io_completion_wq worker is still pending. Both sides of the mm-lifetime race are attacker-driven and freely retryable, so this is not AC:H.\nPR:L - ffs_epfile_open has no capability check. FunctionFS mounts commonly set uid=/gid=/fmode= so unprivileged gadget daemons (adbd/shell, MTP) can open ep files; mounting needs init-namespace CAP_SYS_ADMIN, but using already-mounted endpoints does not.\nUI:N - The attacker performs io_submit and process exit itself. No separate victim action is required beyond an already-deployed FunctionFS gadget.\nS:U - The mm_struct use-after-free corrupts host kernel state within the same security authority. This is standard local kernel privilege escalation, not a VM, IOMMU, or sandbox escape.\nC:H - Use-after-free of mm_struct lets kthread_use_mm/switch_mm consume a reclaimed mm (including mm->pgd) and copy_to_iter through attacker-influenced page tables, yielding an arbitrary read primitive. Per scoring guidance, UAF is Confidentiality High.\nI:H - kthread_use_mm on a sprayed mm_struct can install attacker-controlled page tables, and ffs_copy_to_iter then writes the USB payload through them, giving an arbitrary write and control-flow hijack primitive. Per scoring guidance, UAF is Integrity High.\nA:H - Using a freed mm_struct in kthread_use_mm/switch_mm and copy_to_iter reliably oopses or panics the kernel even without a full exploit, so availability impact is High." } ] } ], "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": "2e4c7553cd6f9c68bb741582dcb614edcbeca70f", "lessThan": "aee2fde0f39e2b667084f4d5cc323a5c5543d733", "status": "affected", "versionType": "git" }, { "version": "2e4c7553cd6f9c68bb741582dcb614edcbeca70f", "lessThan": "1625827648f4e1595ea6ba5521bc87ee5088b32b", "status": "affected", "versionType": "git" }, { "version": "2e4c7553cd6f9c68bb741582dcb614edcbeca70f", "lessThan": "f3d31484b3f26d63c09e5569ebfaa1079a17f171", "status": "affected", "versionType": "git" }, { "version": "2e4c7553cd6f9c68bb741582dcb614edcbeca70f", "lessThan": "7411de0ce3b45286de1de82526795658ea6eacb0", "status": "affected", "versionType": "git" }, { "version": "2e4c7553cd6f9c68bb741582dcb614edcbeca70f", "lessThan": "5eb5c72c72fef76cb765ef1669b62b6a3ba1bfc8", "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": "3.15", "status": "affected" }, { "version": "0", "lessThan": "3.15", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.111", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.51", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.5", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "3.15", "versionEndExcluding": "6.6.160" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.15", "versionEndExcluding": "6.12.111" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.15", "versionEndExcluding": "6.18.51" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.15", "versionEndExcluding": "7.2.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.15", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/aee2fde0f39e2b667084f4d5cc323a5c5543d733" }, { "url": "https://git.kernel.org/stable/c/1625827648f4e1595ea6ba5521bc87ee5088b32b" }, { "url": "https://git.kernel.org/stable/c/f3d31484b3f26d63c09e5569ebfaa1079a17f171" }, { "url": "https://git.kernel.org/stable/c/7411de0ce3b45286de1de82526795658ea6eacb0" }, { "url": "https://git.kernel.org/stable/c/5eb5c72c72fef76cb765ef1669b62b6a3ba1bfc8" } ], "title": "USB: gadget: ffs: fix mm lifetime handling", "x_generator": { "engine": "bippy-1.2.0" } } } }