{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2022-48892", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-08-21T06:06:23.290Z", "datePublished": "2024-08-21T06:10:24.407Z", "dateUpdated": "2026-08-05T08:52:49.416Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:52:49.416Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsched/core: Fix use-after-free bug in dup_user_cpus_ptr()\n\nSince commit 07ec77a1d4e8 (\"sched: Allow task CPU affinity to be\nrestricted on asymmetric systems\"), the setting and clearing of\nuser_cpus_ptr are done under pi_lock for arm64 architecture. However,\ndup_user_cpus_ptr() accesses user_cpus_ptr without any lock\nprotection. Since sched_setaffinity() can be invoked from another\nprocess, the process being modified may be undergoing fork() at\nthe same time. When racing with the clearing of user_cpus_ptr in\n__set_cpus_allowed_ptr_locked(), it can lead to user-after-free and\npossibly double-free in arm64 kernel.\n\nCommit 8f9ea86fdf99 (\"sched: Always preserve the user requested\ncpumask\") fixes this problem as user_cpus_ptr, once set, will never\nbe cleared in a task's lifetime. However, this bug was re-introduced\nin commit 851a723e45d1 (\"sched: Always clear user_cpus_ptr in\ndo_set_cpus_allowed()\") which allows the clearing of user_cpus_ptr in\ndo_set_cpus_allowed(). This time, it will affect all arches.\n\nFix this bug by always clearing the user_cpus_ptr of the newly\ncloned/forked task before the copying process starts and check the\nuser_cpus_ptr state of the source task under pi_lock.\n\nNote to stable, this patch won't be applicable to stable releases.\nJust copy the new dup_user_cpus_ptr() function over." } ], "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 - Reachable only via local syscalls (fork/clone racing with sched_setaffinity); there is no network or adjacent-packet path into dup_user_cpus_ptr().\nAC:L - The attacker controls both sides of the race (one thread/process forking while another same-UID thread repeatedly calls sched_setaffinity on the forking task), so success does not depend on conditions outside attacker control.\nPR:L - An unprivileged user can trigger both fork and sched_setaffinity on their own tasks via check_same_owner without CAP_SYS_NICE; user_cpus_ptr is also established by unprivileged execve on asymmetric arm64.\nUI:N - Exploitation requires no victim action; the attacker triggers fork and affinity changes entirely themselves.\nS:U - This is a standard kernel heap UAF/double-free enabling privilege escalation within the same kernel security authority, not a VM/IOMMU/sandbox boundary cross.\nC:H - Use-after-free of the kmalloc'd cpumask lets an attacker reclaim the object and obtain arbitrary kernel read primitives from the corrupted heap.\nI:H - The same UAF/double-free is exploitable for heap spraying and arbitrary write/control-flow hijack in the kernel, enabling integrity compromise and code execution.\nA:H - The race can NULL-dereference or free still-referenced memory, causing kernel oops/panic, and UAF crashes remain likely even when not fully exploited." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/sched/core.c" ], "versions": [ { "version": "07ec77a1d4e82526e1588979fff2f024f8e96df2", "lessThan": "b22faa21b6230d5eccd233e1b7e0026a5002b287", "status": "affected", "versionType": "git" }, { "version": "07ec77a1d4e82526e1588979fff2f024f8e96df2", "lessThan": "7b5cc7fd1789ea5dbb942c9f8207b076d365badc", "status": "affected", "versionType": "git" }, { "version": "07ec77a1d4e82526e1588979fff2f024f8e96df2", "lessThan": "87ca4f9efbd7cc649ff43b87970888f2812945b8", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/sched/core.c" ], "versions": [ { "version": "5.15", "status": "affected" }, { "version": "0", "lessThan": "5.15", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.89", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.7", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.2", "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": "5.15", "versionEndExcluding": "5.15.89" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.1.7" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/b22faa21b6230d5eccd233e1b7e0026a5002b287" }, { "url": "https://git.kernel.org/stable/c/7b5cc7fd1789ea5dbb942c9f8207b076d365badc" }, { "url": "https://git.kernel.org/stable/c/87ca4f9efbd7cc649ff43b87970888f2812945b8" } ], "title": "sched/core: Fix use-after-free bug in dup_user_cpus_ptr()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2022-48892", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2024-09-10T16:04:18.997658Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-09-12T17:33:06.281Z" } } ] } }