{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2022-49647","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2025-02-26T02:21:30.432Z","datePublished":"2025-02-26T02:23:51.561Z","dateUpdated":"2026-08-05T08:55:55.097Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T08:55:55.097Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ncgroup: Use separate src/dst nodes when preloading css_sets for migration\n\nEach cset (css_set) is pinned by its tasks. When we're moving tasks around\nacross csets for a migration, we need to hold the source and destination\ncsets to ensure that they don't go away while we're moving tasks about. This\nis done by linking cset->mg_preload_node on either the\nmgctx->preloaded_src_csets or mgctx->preloaded_dst_csets list. Using the\nsame cset->mg_preload_node for both the src and dst lists was deemed okay as\na cset can't be both the source and destination at the same time.\n\nUnfortunately, this overloading becomes problematic when multiple tasks are\ninvolved in a migration and some of them are identity noop migrations while\nothers are actually moving across cgroups. For example, this can happen with\nthe following sequence on cgroup1:\n\n #1> mkdir -p /sys/fs/cgroup/misc/a/b\n #2> echo $$ > /sys/fs/cgroup/misc/a/cgroup.procs\n #3> RUN_A_COMMAND_WHICH_CREATES_MULTIPLE_THREADS &\n #4> PID=$!\n #5> echo $PID > /sys/fs/cgroup/misc/a/b/tasks\n #6> echo $PID > /sys/fs/cgroup/misc/a/cgroup.procs\n\nthe process including the group leader back into a. In this final migration,\nnon-leader threads would be doing identity migration while the group leader\nis doing an actual one.\n\nAfter #3, let's say the whole process was in cset A, and that after #4, the\nleader moves to cset B. Then, during #6, the following happens:\n\n 1. cgroup_migrate_add_src() is called on B for the leader.\n\n 2. cgroup_migrate_add_src() is called on A for the other threads.\n\n 3. cgroup_migrate_prepare_dst() is called. It scans the src list.\n\n 4. It notices that B wants to migrate to A, so it tries to A to the dst\n    list but realizes that its ->mg_preload_node is already busy.\n\n 5. and then it notices A wants to migrate to A as it's an identity\n    migration, it culls it by list_del_init()'ing its ->mg_preload_node and\n    putting references accordingly.\n\n 6. The rest of migration takes place with B on the src list but nothing on\n    the dst list.\n\nThis means that A isn't held while migration is in progress. If all tasks\nleave A before the migration finishes and the incoming task pins it, the\ncset will be destroyed leading to use-after-free.\n\nThis is caused by overloading cset->mg_preload_node for both src and dst\npreload lists. We wanted to exclude the cset from the src list but ended up\ninadvertently excluding it from the dst list too.\n\nThis patch fixes the issue by separating out cset->mg_preload_node into\n->mg_src_preload_node and ->mg_dst_preload_node, so that the src and dst\npreloadings don't interfere with each other."}],"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 bug is triggered by writing to cgroupfs control files (cgroup.procs/tasks/cgroup.threads) via local syscalls on the mounted cgroup filesystem, not by network packet processing or adjacent-network protocols.\nAC:L - An attacker fully controls the migration sequence (multi-threaded process, per-thread move via tasks/cgroup.threads, then whole-process move via cgroup.procs) and can arrange concurrent task teardown that drops the last css_set refs, so success does not depend on victim-side conditions outside attacker influence.\nPR:L - Write access to a delegated cgroup subtree is sufficient: mkdir sets file ownership to the creator (cgroup_kn_set_ugid), cgroup.procs/threads are NS_DELEGATABLE, and cgroup1 only requires euid match to move one's own tasks—common for containers and systemd Delegate= setups without real init-ns root.\nUI:N - The attacker performs the cgroup writes and process/thread setup directly; no separate victim user action is required.\nS:U - This is a host-kernel css_set use-after-free enabling privilege escalation within the same kernel authority, not a VM/IOMMU/sandbox boundary escape.\nC:H - The bug is a use-after-free of a css_set used as the migration destination; UAF of a kernel object enables reclaim/spray and arbitrary read primitives.\nI:H - The same css_set UAF is exploitable for heap manipulation and control-flow hijacking / arbitrary write, enabling integrity compromise and code execution in kernel context.\nA:H - Dereferencing the unpinned/freed destination css_set during cgroup_migrate_execute can oops/panic the kernel even when not fully exploited for code execution."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/cgroup-defs.h","kernel/cgroup/cgroup.c"],"versions":[{"version":"f817de98513d060023be4fa1d061b29a6515273e","lessThan":"05f7658210d1d331e8dd4cb6e7bbbe3df5f5ac27","status":"affected","versionType":"git"},{"version":"f817de98513d060023be4fa1d061b29a6515273e","lessThan":"cec2bbdcc14fbaa6b95ee15a7c423b05d97038be","status":"affected","versionType":"git"},{"version":"f817de98513d060023be4fa1d061b29a6515273e","lessThan":"ad44e05f3e016bdcb1ad25af35ade5b5f41ccd68","status":"affected","versionType":"git"},{"version":"f817de98513d060023be4fa1d061b29a6515273e","lessThan":"7657e3958535d101a24ab4400f9b8062b9107cc4","status":"affected","versionType":"git"},{"version":"f817de98513d060023be4fa1d061b29a6515273e","lessThan":"54aee4e5ce8c21555286a6333e46c1713880cf93","status":"affected","versionType":"git"},{"version":"f817de98513d060023be4fa1d061b29a6515273e","lessThan":"0e41774b564befa6d271e8d5086bf870d617a4e6","status":"affected","versionType":"git"},{"version":"f817de98513d060023be4fa1d061b29a6515273e","lessThan":"07fd5b6cdf3cc30bfde8fe0f644771688be04447","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/cgroup-defs.h","kernel/cgroup/cgroup.c"],"versions":[{"version":"3.16","status":"affected"},{"version":"0","lessThan":"3.16","status":"unaffected","versionType":"semver"},{"version":"4.14.289","lessThanOrEqual":"4.14.*","status":"unaffected","versionType":"semver"},{"version":"4.19.253","lessThanOrEqual":"4.19.*","status":"unaffected","versionType":"semver"},{"version":"5.4.207","lessThanOrEqual":"5.4.*","status":"unaffected","versionType":"semver"},{"version":"5.10.132","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.56","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"5.18.13","lessThanOrEqual":"5.18.*","status":"unaffected","versionType":"semver"},{"version":"5.19","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":"3.16","versionEndExcluding":"4.14.289"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"4.19.253"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"5.4.207"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"5.10.132"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"5.15.56"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"5.18.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"5.19"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/05f7658210d1d331e8dd4cb6e7bbbe3df5f5ac27"},{"url":"https://git.kernel.org/stable/c/cec2bbdcc14fbaa6b95ee15a7c423b05d97038be"},{"url":"https://git.kernel.org/stable/c/ad44e05f3e016bdcb1ad25af35ade5b5f41ccd68"},{"url":"https://git.kernel.org/stable/c/7657e3958535d101a24ab4400f9b8062b9107cc4"},{"url":"https://git.kernel.org/stable/c/54aee4e5ce8c21555286a6333e46c1713880cf93"},{"url":"https://git.kernel.org/stable/c/0e41774b564befa6d271e8d5086bf870d617a4e6"},{"url":"https://git.kernel.org/stable/c/07fd5b6cdf3cc30bfde8fe0f644771688be04447"}],"title":"cgroup: Use separate src/dst nodes when preloading css_sets for migration","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":7.8,"attackVector":"LOCAL","baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","integrityImpact":"HIGH","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"HIGH","privilegesRequired":"LOW","confidentialityImpact":"HIGH"}},{"other":{"type":"ssvc","content":{"id":"CVE-2022-49647","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2025-02-27T18:15:22.179725Z"}}}],"problemTypes":[{"descriptions":[{"lang":"en","type":"CWE","cweId":"CWE-416","description":"CWE-416 Use After Free"}]}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2025-02-27T18:22:31.480Z"}}]}}