{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-43853", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-08-17T09:11:59.277Z", "datePublished": "2024-08-17T09:22:10.534Z", "dateUpdated": "2026-08-05T11:36:48.073Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:36:48.073Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncgroup/cpuset: Prevent UAF in proc_cpuset_show()\n\nAn UAF can happen when /proc/cpuset is read as reported in [1].\n\nThis can be reproduced by the following methods:\n1.add an mdelay(1000) before acquiring the cgroup_lock In the\n cgroup_path_ns function.\n2.$cat /proc//cpuset repeatly.\n3.$mount -t cgroup -o cpuset cpuset /sys/fs/cgroup/cpuset/\n$umount /sys/fs/cgroup/cpuset/ repeatly.\n\nThe race that cause this bug can be shown as below:\n\n(umount)\t\t|\t(cat /proc//cpuset)\ncss_release\t\t|\tproc_cpuset_show\ncss_release_work_fn\t|\tcss = task_get_css(tsk, cpuset_cgrp_id);\ncss_free_rwork_fn\t|\tcgroup_path_ns(css->cgroup, ...);\ncgroup_destroy_root\t|\tmutex_lock(&cgroup_mutex);\nrebind_subsystems\t|\ncgroup_free_root \t|\n\t\t\t|\t// cgrp was freed, UAF\n\t\t\t|\tcgroup_path_ns_locked(cgrp,..);\n\nWhen the cpuset is initialized, the root node top_cpuset.css.cgrp\nwill point to &cgrp_dfl_root.cgrp. In cgroup v1, the mount operation will\nallocate cgroup_root, and top_cpuset.css.cgrp will point to the allocated\n&cgroup_root.cgrp. When the umount operation is executed,\ntop_cpuset.css.cgrp will be rebound to &cgrp_dfl_root.cgrp.\n\nThe problem is that when rebinding to cgrp_dfl_root, there are cases\nwhere the cgroup_root allocated by setting up the root for cgroup v1\nis cached. This could lead to a Use-After-Free (UAF) if it is\nsubsequently freed. The descendant cgroups of cgroup v1 can only be\nfreed after the css is released. However, the css of the root will never\nbe released, yet the cgroup_root should be freed when it is unmounted.\nThis means that obtaining a reference to the css of the root does\nnot guarantee that css.cgrp->root will not be freed.\n\nFix this problem by using rcu_read_lock in proc_cpuset_show().\nAs cgroup_root is kfree_rcu after commit d23b5c577715\n(\"cgroup: Make operations on the cgroup root_list RCU safe\"),\ncss->cgroup won't be freed during the critical section.\nTo call cgroup_path_ns_locked, css_set_lock is needed, so it is safe to\nreplace task_get_css with task_css.\n\n[1] https://syzkaller.appspot.com/bug?extid=9b1ff7be974a403aa4cd" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable path is reached by reading /proc//cpuset, and the freeing side is the mount/umount syscall path for a cgroup-v1 cpuset hierarchy; both require local access to the system with no network exposure.\nAC:H - The unprivileged attacker controls only the read side of the race (looping on /proc/self/cpuset); the cgroup_destroy_root()/cgroup_free_root() side requires a cgroup-v1 umount that CAP_SYS_ADMIN checks in cgroup1_get_tree() and the init_cgroup_ns restriction put beyond the attacker's control, so the attacker must wait for privileged mount/umount activity.\nPR:L - proc_cpuset_show is registered S_IRUGO and any unprivileged local user can read /proc/self/cpuset to enter the vulnerable function; no capability is needed to trigger the use-after-free dereference itself.\nUI:N - No victim action is needed for the attacker's own operations — the attacker simply reads a world-readable procfs file in a loop; the concurrent umount is a system/administrative event modeled under attack complexity, not a targeted user interaction.\nS:U - The use-after-free occurs in kernel memory and its impact stays within the kernel's own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - kernfs_path_from_node() dereferences freed cgroup_root/kernfs_node memory and copies the resulting name strings directly into the buffer emitted to userspace via /proc//cpuset, so a reallocated/sprayed slab yields kernel memory disclosure to the attacker.\nI:H - This is a use-after-free on a kfree_rcu'd cgroup_root plus torn-down kernfs nodes; controlling the reallocated object gives pointer-controlled dereferences that can be leveraged with heap grooming for corruption and control-flow influence.\nA:H - The freed cgrp_cset_link list makes cset_cgroup_from_root() return NULL, leading to a NULL/wild dereference in kernfs_path_from_node(), and the UAF reliably produces an oops or panic (this is exactly how syzkaller reported it)." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/cgroup/cpuset.c" ], "versions": [ { "version": "a79a908fd2b080977b45bf103184b81c9d11ad07", "lessThan": "27d6dbdc6485d68075a0ebf8544d6425c1ed84bb", "status": "affected", "versionType": "git" }, { "version": "a79a908fd2b080977b45bf103184b81c9d11ad07", "lessThan": "10aeaa47e4aa2432f29b3e5376df96d7dac5537a", "status": "affected", "versionType": "git" }, { "version": "a79a908fd2b080977b45bf103184b81c9d11ad07", "lessThan": "688325078a8b5badd6e07ae22b27cd04e9947aec", "status": "affected", "versionType": "git" }, { "version": "a79a908fd2b080977b45bf103184b81c9d11ad07", "lessThan": "4e8d6ac8fc9f843e940ab7389db8136634e07989", "status": "affected", "versionType": "git" }, { "version": "a79a908fd2b080977b45bf103184b81c9d11ad07", "lessThan": "29a8d4e02fd4840028c38ceb1536cc8f82a257d4", "status": "affected", "versionType": "git" }, { "version": "a79a908fd2b080977b45bf103184b81c9d11ad07", "lessThan": "96226fbed566f3f686f53a489a29846f2d538080", "status": "affected", "versionType": "git" }, { "version": "a79a908fd2b080977b45bf103184b81c9d11ad07", "lessThan": "29ac1d238b3bf126af36037df80d7ecc4822341e", "status": "affected", "versionType": "git" }, { "version": "a79a908fd2b080977b45bf103184b81c9d11ad07", "lessThan": "1be59c97c83ccd67a519d8a49486b3a8a73ca28a", "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/cgroup/cpuset.c" ], "versions": [ { "version": "4.6", "status": "affected" }, { "version": "0", "lessThan": "4.6", "status": "unaffected", "versionType": "semver" }, { "version": "4.19.321", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.283", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.225", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.166", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.103", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.44", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.10.3", "lessThanOrEqual": "6.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.11", "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": "4.6", "versionEndExcluding": "4.19.321" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.6", "versionEndExcluding": "5.4.283" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.6", "versionEndExcluding": "5.10.225" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.6", "versionEndExcluding": "5.15.166" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.6", "versionEndExcluding": "6.1.103" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.6", "versionEndExcluding": "6.6.44" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.6", "versionEndExcluding": "6.10.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.6", "versionEndExcluding": "6.11" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/27d6dbdc6485d68075a0ebf8544d6425c1ed84bb" }, { "url": "https://git.kernel.org/stable/c/10aeaa47e4aa2432f29b3e5376df96d7dac5537a" }, { "url": "https://git.kernel.org/stable/c/688325078a8b5badd6e07ae22b27cd04e9947aec" }, { "url": "https://git.kernel.org/stable/c/4e8d6ac8fc9f843e940ab7389db8136634e07989" }, { "url": "https://git.kernel.org/stable/c/29a8d4e02fd4840028c38ceb1536cc8f82a257d4" }, { "url": "https://git.kernel.org/stable/c/96226fbed566f3f686f53a489a29846f2d538080" }, { "url": "https://git.kernel.org/stable/c/29ac1d238b3bf126af36037df80d7ecc4822341e" }, { "url": "https://git.kernel.org/stable/c/1be59c97c83ccd67a519d8a49486b3a8a73ca28a" } ], "title": "cgroup/cpuset: Prevent UAF in proc_cpuset_show()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2024-43853", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2024-09-10T16:07:17.671649Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-09-12T17:33:20.917Z" } }, { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html" }, { "url": "https://lists.debian.org/debian-lts-announce/2024/10/msg00003.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T22:05:48.844Z" } } ] } }