{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-53161", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-06-09T07:44:35.388Z", "datePublished": "2026-06-25T08:38:42.789Z", "dateUpdated": "2026-08-05T12:33:36.090Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:33:36.090Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmisc: fastrpc: fix use-after-free of fastrpc_user in workqueue context\n\nThere is a race between fastrpc_device_release() and the workqueue\nthat processes DSP responses. When the user closes the file descriptor,\nfastrpc_device_release() frees the fastrpc_user structure. Concurrently,\nan in-flight DSP invocation can complete and fastrpc_rpmsg_callback()\nschedules context cleanup via schedule_work(&ctx->put_work). If the\nworkqueue runs fastrpc_context_free() in parallel with or after\nfastrpc_device_release() has freed the user structure, it dereferences\nthe freed fastrpc_user. Depending on the state of the context at the\ntime of the race, any one of the following accesses can be hit:\n\n 1. fastrpc_buf_free() calls fastrpc_ipa_to_dma_addr(buf->fl->cctx, ...)\n to strip the SID bits from the stored IOVA before passing the\n physical address to dma_free_coherent().\n\n 2. fastrpc_free_map() reads map->fl->cctx->vmperms[0].vmid to\n reconstruct the source permission bitmask needed for the\n qcom_scm_assign_mem() call that returns memory from the DSP VM\n back to HLOS.\n\n 3. fastrpc_free_map() acquires map->fl->lock to safely remove the\n map node from the fl->maps list.\n\nThe resulting use-after-free manifests as:\n\n pc : fastrpc_buf_free+0x38/0x80 [fastrpc]\n lr : fastrpc_context_free+0xa8/0x1b0 [fastrpc]\n fastrpc_context_free+0xa8/0x1b0 [fastrpc]\n fastrpc_context_put_wq+0x78/0xa0 [fastrpc]\n process_one_work+0x180/0x450\n worker_thread+0x26c/0x388\n\nAdd kref-based reference counting to fastrpc_user. Have each invoke\ncontext take a reference on the user at allocation time and release it\nwhen the context is freed. Release the initial reference in\nfastrpc_device_release() at file close. Move the teardown of the user\nstructure — freeing pending contexts, maps, mmaps, and the channel\ncontext reference — into the kref release callback fastrpc_user_free(),\nso that it runs only when the last reference is dropped, regardless of\nwhether that happens at device close or after the final in-flight\ncontext completes." } ], "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 vulnerable code is reached through local FastRPC misc-device file operations and ioctls on /dev/fastrpc-* rather than by network or physical input.\nAC:L - The attacker can create in-flight DSP invokes and race close/interruption against DSP response workqueue cleanup, and the race can be retried under attacker control.\nPR:L - No in-driver capability check gates open or invoke; in plausible Qualcomm/Android deployments an unprivileged local app can reach FastRPC directly or through a HAL-provided fd.\nUI:N - Exploitation requires only attacker-controlled local ioctls, close, and timing; no separate victim action is needed.\nS:U - The memory corruption affects the kernel driver and kernel memory within the same OS security authority, with no VM or sandbox boundary escape inherent to the bug.\nC:H - This is a kernel use-after-free of fastrpc_user reachable from deferred context cleanup, and UAF conditions can be shaped into kernel memory disclosure primitives.\nI:H - The UAF can dereference attacker-reclaimed kernel heap state through buffer/map cleanup paths, making kernel memory corruption and potential control-flow or arbitrary-write exploitation defensible.\nA:H - At minimum the stale fastrpc_user dereference can crash or oops the kernel during workqueue cleanup, causing high availability impact." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/misc/fastrpc.c" ], "versions": [ { "version": "6cffd79504ce040f460831030d3069fa1c99bb71", "lessThan": "c6e5c2be09f814377d7f1ce97370a5b7b3e02814", "status": "affected", "versionType": "git" }, { "version": "6cffd79504ce040f460831030d3069fa1c99bb71", "lessThan": "e1e3a05efe5954d5bad01157d79429d39a67a7ae", "status": "affected", "versionType": "git" }, { "version": "6cffd79504ce040f460831030d3069fa1c99bb71", "lessThan": "d42679eef34dd590b694ce3b666c5e2ba10cd4bf", "status": "affected", "versionType": "git" }, { "version": "6cffd79504ce040f460831030d3069fa1c99bb71", "lessThan": "df08fadcf0e5f3708365ec3b6d30b5aafd98bea1", "status": "affected", "versionType": "git" }, { "version": "6cffd79504ce040f460831030d3069fa1c99bb71", "lessThan": "ecea4967c2bff92c2fafbc59893f711b39f7b152", "status": "affected", "versionType": "git" }, { "version": "6cffd79504ce040f460831030d3069fa1c99bb71", "lessThan": "5278ccd357e0d7aeeb1e76c0f3e0e02894a9897c", "status": "affected", "versionType": "git" }, { "version": "6cffd79504ce040f460831030d3069fa1c99bb71", "lessThan": "fbe0947420eec18a84638d29468c2d563ce4e6a3", "status": "affected", "versionType": "git" }, { "version": "6cffd79504ce040f460831030d3069fa1c99bb71", "lessThan": "e85eb5feca8e254905ffa6c57a3c99c89a674a0f", "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/misc/fastrpc.c" ], "versions": [ { "version": "5.1", "status": "affected" }, { "version": "0", "lessThan": "5.1", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.259", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.210", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.176", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.143", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.94", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.36", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.13", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "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": "5.1", "versionEndExcluding": "5.10.259" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "5.15.210" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.1.176" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.6.143" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.12.94" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.18.36" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "7.0.13" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/c6e5c2be09f814377d7f1ce97370a5b7b3e02814" }, { "url": "https://git.kernel.org/stable/c/e1e3a05efe5954d5bad01157d79429d39a67a7ae" }, { "url": "https://git.kernel.org/stable/c/d42679eef34dd590b694ce3b666c5e2ba10cd4bf" }, { "url": "https://git.kernel.org/stable/c/df08fadcf0e5f3708365ec3b6d30b5aafd98bea1" }, { "url": "https://git.kernel.org/stable/c/ecea4967c2bff92c2fafbc59893f711b39f7b152" }, { "url": "https://git.kernel.org/stable/c/5278ccd357e0d7aeeb1e76c0f3e0e02894a9897c" }, { "url": "https://git.kernel.org/stable/c/fbe0947420eec18a84638d29468c2d563ce4e6a3" }, { "url": "https://git.kernel.org/stable/c/e85eb5feca8e254905ffa6c57a3c99c89a674a0f" } ], "title": "misc: fastrpc: fix use-after-free of fastrpc_user in workqueue context", "x_generator": { "engine": "bippy-1.2.0" } } } }