| { |
| "containers": { |
| "cna": { |
| "providerMetadata": { |
| "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038" |
| }, |
| "descriptions": [ |
| { |
| "lang": "en", |
| "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncgroup: Fix memory leak caused by missing cgroup_bpf_offline\n\nWhen enabling CONFIG_CGROUP_BPF, kmemleak can be observed by running\nthe command as below:\n\n $mount -t cgroup -o none,name=foo cgroup cgroup/\n $umount cgroup/\n\nunreferenced object 0xc3585c40 (size 64):\n comm \"mount\", pid 425, jiffies 4294959825 (age 31.990s)\n hex dump (first 32 bytes):\n 01 00 00 80 84 8c 28 c0 00 00 00 00 00 00 00 00 ......(.........\n 00 00 00 00 00 00 00 00 6c 43 a0 c3 00 00 00 00 ........lC......\n backtrace:\n [<e95a2f9e>] cgroup_bpf_inherit+0x44/0x24c\n [<1f03679c>] cgroup_setup_root+0x174/0x37c\n [<ed4b0ac5>] cgroup1_get_tree+0x2c0/0x4a0\n [<f85b12fd>] vfs_get_tree+0x24/0x108\n [<f55aec5c>] path_mount+0x384/0x988\n [<e2d5e9cd>] do_mount+0x64/0x9c\n [<208c9cfe>] sys_mount+0xfc/0x1f4\n [<06dd06e0>] ret_fast_syscall+0x0/0x48\n [<a8308cb3>] 0xbeb4daa8\n\nThis is because that since the commit 2b0d3d3e4fcf (\"percpu_ref: reduce\nmemory footprint of percpu_ref in fast path\") root_cgrp->bpf.refcnt.data\nis allocated by the function percpu_ref_init in cgroup_bpf_inherit which\nis called by cgroup_setup_root when mounting, but not freed along with\nroot_cgrp when umounting. Adding cgroup_bpf_offline which calls\npercpu_ref_kill to cgroup_kill_sb can free root_cgrp->bpf.refcnt.data in\numount path.\n\nThis patch also fixes the commit 4bfc0bb2c60e (\"bpf: decouple the lifetime\nof cgroup_bpf from cgroup itself\"). A cgroup_bpf_offline is needed to do a\ncleanup that frees the resources which are allocated by cgroup_bpf_inherit\nin cgroup_setup_root.\n\nAnd inside cgroup_bpf_offline, cgroup_get() is at the beginning and\ncgroup_put is at the end of cgroup_bpf_release which is called by\ncgroup_bpf_offline. So cgroup_bpf_offline can keep the balance of\ncgroup's refcount." |
| } |
| ], |
| "affected": [ |
| { |
| "product": "Linux", |
| "vendor": "Linux", |
| "defaultStatus": "unaffected", |
| "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", |
| "programFiles": [ |
| "kernel/cgroup/cgroup.c" |
| ], |
| "versions": [ |
| { |
| "version": "4bfc0bb2c60e", |
| "lessThan": "01599bf7cc2b", |
| "status": "affected", |
| "versionType": "git" |
| }, |
| { |
| "version": "4bfc0bb2c60e", |
| "lessThan": "b529f88d9388", |
| "status": "affected", |
| "versionType": "git" |
| }, |
| { |
| "version": "4bfc0bb2c60e", |
| "lessThan": "04f8ef5643bc", |
| "status": "affected", |
| "versionType": "git" |
| }, |
| { |
| "version": "4bfc0bb2c60e", |
| "lessThan": "966666b70b86", |
| "status": "affected", |
| "versionType": "git" |
| }, |
| { |
| "version": "4bfc0bb2c60e", |
| "lessThan": "dd6ade970de9", |
| "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/cgroup.c" |
| ], |
| "versions": [ |
| { |
| "version": "5.3", |
| "status": "affected" |
| }, |
| { |
| "version": "0", |
| "lessThan": "5.3", |
| "status": "unaffected", |
| "versionType": "semver" |
| }, |
| { |
| "version": "5.10.77", |
| "lessThanOrEqual": "5.10.*", |
| "status": "unaffected", |
| "versionType": "semver" |
| }, |
| { |
| "version": "5.14.16", |
| "lessThanOrEqual": "5.14.*", |
| "status": "unaffected", |
| "versionType": "semver" |
| }, |
| { |
| "version": "5.15", |
| "lessThanOrEqual": "*", |
| "status": "unaffected", |
| "versionType": "original_commit_for_fix" |
| }, |
| { |
| "version": "6.11.11", |
| "lessThanOrEqual": "6.11.*", |
| "status": "unaffected", |
| "versionType": "semver" |
| }, |
| { |
| "version": "6.12.2", |
| "lessThanOrEqual": "6.12.*", |
| "status": "unaffected", |
| "versionType": "semver" |
| } |
| ] |
| } |
| ], |
| "references": [ |
| { |
| "url": "https://git.kernel.org/stable/c/01599bf7cc2b49c3d2be886cb438647dc25446ed" |
| }, |
| { |
| "url": "https://git.kernel.org/stable/c/b529f88d93884cf8ccafda793ee3d27b82fa578d" |
| }, |
| { |
| "url": "https://git.kernel.org/stable/c/04f8ef5643bcd8bcde25dfdebef998aea480b2ba" |
| }, |
| { |
| "url": "https://git.kernel.org/stable/c/966666b70b86c96843c4e143bd59c83e3082d1b4" |
| }, |
| { |
| "url": "https://git.kernel.org/stable/c/dd6ade970de9378ad86ef027c1a6b9ef15e2d393" |
| } |
| ], |
| "title": "cgroup: Fix memory leak caused by missing cgroup_bpf_offline", |
| "x_generator": { |
| "engine": "bippy-8e903de6a542" |
| } |
| } |
| }, |
| "cveMetadata": { |
| "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038", |
| "cveID": "CVE-2021-47488", |
| "requesterUserId": "gregkh@kernel.org", |
| "serial": "1", |
| "state": "PUBLISHED" |
| }, |
| "dataType": "CVE_RECORD", |
| "dataVersion": "5.0" |
| } |
