cbcvebase.
CVE-2025-68736
published 2025-12-24

CVE-2025-68736: In the Linux kernel, the following vulnerability has been resolved: landlock: Fix handling of disconnected directories Disconnected files or directories can…

PriorityP347high8.8CVSS 3.1
AVLACLPRLUINSCCHIHAH
EPSS
0.12%
2.6th percentile
In the Linux kernel, the following vulnerability has been resolved: landlock: Fix handling of disconnected directories Disconnected files or directories can appear when they are visible and opened from a bind mount, but have been renamed or moved from the source of the bind mount in a way that makes them inaccessible from the mount point (i.e. out of scope). Previously, access rights tied to files or directories opened through a disconnected directory were collected by walking the related hierarchy down to the root of the filesystem, without taking into account the mount point because it couldn't be found. This could lead to inconsistent access results, potential access right widening, and hard-to-debug renames, especially since such paths cannot be printed. For a sandboxed task to create a disconnected directory, it needs to have write access (i.e. FS_MAKE_REG, FS_REMOVE_FILE, and FS_REFER) to the underlying source of the bind mount, and read access to the related mount point. Because a sandboxed task cannot acquire more access rights than those defined by its Landlock domain, this could lead to inconsistent access rights due to missing permissions that should be inherited from the mount point hierarchy, while inheriting permissions from the filesystem hierarchy hidden by this mount point instead. Landlock now handles files and directories opened from disconnected directories by taking into account the filesystem hierarchy when the mount point is not found in the hierarchy walk, and also always taking into account the mount point from which these disconnected directories were opened. This ensures that a rename is not allowed if it would widen access rights [1]. The rationale is that, even if disconnected hierarchies might not be visible or accessible to a sandboxed task, relying on the collected access rights from them improves the guarantee that access rights will not be widened during a rename because of the access right comparison between the source and th

Affected

45 ranges· showing 25
VendorProductVersion rangeFixed in
debianlinux< linux 6.18.3-1 (forky)linux 6.18.3-1 (forky)
linuxlinux
linuxlinux>= cb2c7d1a1776057c9a1f48ed1250d85e94d4850d < fbf718d5afe21057694a0c0223a18b0c7a5960b6fbf718d5afe21057694a0c0223a18b0c7a5960b6
linuxlinux>= cb2c7d1a1776057c9a1f48ed1250d85e94d4850d < 426d5b681b2f3339ff04da39b81d71176dc8c87c426d5b681b2f3339ff04da39b81d71176dc8c87c
linuxlinux>= cb2c7d1a1776057c9a1f48ed1250d85e94d4850d < cadb28f8b3fd6908e3051e86158c65c3a8e1c907cadb28f8b3fd6908e3051e86158c65c3a8e1c907
linuxlinux>= cb2c7d1a1776057c9a1f48ed1250d85e94d4850d < 49c9e09d961025b22e61ef9ad56aa1c21b6ce2f149c9e09d961025b22e61ef9ad56aa1c21b6ce2f1
linuxlinux_kernel>= 0 < 6.18.3-16.18.3-1
linuxlinux_kernel>= 5.13.0 < 6.18.26.18.2
msrcazl3_kernel_6.6.117.1-1_on_azure_linux_3.0
msrcazl3_kernel_6.6.119.3-1_on_azure_linux_3.0
msrcazl3_kernel_6.6.119.3-3_on_azure_linux_3.0
msrcazl3_kernel_6.6.121.1-1_on_azure_linux_3.0
msrcazl3_kernel_6.6.126.1-1_on_azure_linux_3.0
msrcazl3_kernel_6.6.130.1-3_on_azure_linux_3.0
ubuntulinux
ubuntulinux-aws
ubuntulinux-aws-6.17
ubuntulinux-azure
ubuntulinux-azure-6.17
ubuntulinux-azure-6.8
ubuntulinux-azure-fde
ubuntulinux-azure-fde-6.8
ubuntulinux-azure-fips
ubuntulinux-fips
ubuntulinux-gcp

CVSS provenance

nvdv3.18.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
vendor_ubuntu6.4MEDIUM
vendor_redhat6.1MEDIUM
vendor_msrc5.5MEDIUM
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