{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-74619", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.921Z", "datePublished": "2026-08-22T15:32:03.511Z", "dateUpdated": "2026-08-22T15:32:03.511Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-22T15:32:03.511Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\novl: don't warn when the mount is completed from another user namespace\n\nfsopen() records the caller's user namespace in fc->user_ns and hands\nback an ordinary file descriptor. Nothing ties the task that calls\nfsconfig(FSCONFIG_CMD_CREATE) to the task that created the context. The\nfd is inherited across fork() and exec() and it can be passed over a\nunix socket.\n\nCompleting a context from another user namespace is allowed on purpose.\nvfs_cmd_create() authorizes the create with mount_capable(), which for\nFS_USERNS_MOUNT checks ns_capable(fc->user_ns, CAP_SYS_ADMIN), and that\nsucceeds for a task holding CAP_SYS_ADMIN in an ancestor of fc->user_ns.\nSo an unprivileged task can reach the WARN_ON() in ovl_fill_super():\ncreate a user and a mount namespace in a child, call fsopen(\"overlay\")\nthere, send the fscontext fd to the parent and let the parent issue\nFSCONFIG_CMD_CREATE. Both namespaces come from a plain unshare(1) and no\ncapability is needed anywhere:\n\n WARNING: fs/overlayfs/super.c:1551 at ovl_fill_super+0x7b9/0x1e20 [overlay]\n CPU: 3 UID: 1000 PID: 3243376 Comm: fswarn\n Call Trace:\n get_tree_nodev+0x71/0xa0\n ovl_get_tree+0x15/0x20 [overlay]\n vfs_get_tree+0x2a/0x100\n vfs_cmd_create+0x60/0xf0\n __do_sys_fsconfig+0x4b2/0x500\n\nThe child needs the mount namespace because fsopen() itself gates on\nmay_mount(), which asks for CAP_SYS_ADMIN in the user namespace owning\nthe caller's mount namespace. fsconfig() doesn't repeat that check.\n\nIt is a WARN_ON() and not a WARN_ON_ONCE(), so the condition can be\nraised in a loop to taint the kernel and flood the log, and it panics a\nkernel booted with panic_on_warn.\n\nKeep refusing the mount and stop warning about it. ovl_parse_param()\nalready spells a user namespace check this way for Opt_override_creds." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/overlayfs/super.c" ], "versions": [ { "version": "1784fbc2ed9c888ea4e895f30a53207ed7ee8208", "lessThan": "513478092966dc9818d96dd2b3ed613fd2f6e30e", "status": "affected", "versionType": "git" }, { "version": "1784fbc2ed9c888ea4e895f30a53207ed7ee8208", "lessThan": "494346f2aab2489d379d43ff614aea447cf4e94d", "status": "affected", "versionType": "git" }, { "version": "1784fbc2ed9c888ea4e895f30a53207ed7ee8208", "lessThan": "be161fa31e3e9cc828a3c1bd935edca461e8a7a1", "status": "affected", "versionType": "git" }, { "version": "1784fbc2ed9c888ea4e895f30a53207ed7ee8208", "lessThan": "42d99fcd8006007e2f708bede6789f37f3910b30", "status": "affected", "versionType": "git" }, { "version": "1784fbc2ed9c888ea4e895f30a53207ed7ee8208", "lessThan": "63981fc786daaa626cb14d9be1406f674d79f98f", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/overlayfs/super.c" ], "versions": [ { "version": "6.5", "status": "affected" }, { "version": "0", "lessThan": "6.5", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.152", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.104", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.45", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.9", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "6.5", "versionEndExcluding": "6.6.152" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.5", "versionEndExcluding": "6.12.104" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.5", "versionEndExcluding": "6.18.45" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.5", "versionEndExcluding": "7.1.9" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.5", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/513478092966dc9818d96dd2b3ed613fd2f6e30e" }, { "url": "https://git.kernel.org/stable/c/494346f2aab2489d379d43ff614aea447cf4e94d" }, { "url": "https://git.kernel.org/stable/c/be161fa31e3e9cc828a3c1bd935edca461e8a7a1" }, { "url": "https://git.kernel.org/stable/c/42d99fcd8006007e2f708bede6789f37f3910b30" }, { "url": "https://git.kernel.org/stable/c/63981fc786daaa626cb14d9be1406f674d79f98f" } ], "title": "ovl: don't warn when the mount is completed from another user namespace", "x_generator": { "engine": "bippy-1.2.0" } } } }