Threats Tagged 'cve-2026-13595'

This update for util-linux fixes the following issues: - CVE-2026-13595: heap use-after-free in `libblkid` nested partition probing (bsc#1269583). - CVE-2026-27456: TOCTOU in the mount program when setting up loop devices (bsc#1261606). - CVE-2026-53612: local privilege escalation via TOCTOU in mount(8) hook_owner.c chmod/chown (bsc#1268886). - CVE-2026-53613: local privilege escalation via TOCTOU in mount(8) - Target Path Redirection (bsc#1268886). - CVE-2026-53614: local privilege escalation via LIBMOUNT_FORCE_MOUNT2 Environment Variable - nosuid/noexec Bypass in SUID mount(8) (bsc#1268886). - CVE-2026-76642: failed external mount helper triggers privileged `X-mount` post-hooks, which enables local privilege escalation (bsc#1278349). - CVE-2026-78408: `nsenter --join-cgroup` leaks root `cgroup` migration authority, which allows for migration or termination of root processes (bsc#1278348). - CVE-2026-78410: restricted `bind` mounts do not pin the source, which allows for `X-mount.owner`/`group`/`mode` redirection (bsc#1278347). Changes for util-linux: - lib/fileutils: add ul_openat_resolve() openat2 wrapper (bsc#1275441) - lib/fileutils: fix RESOLVE_NO_SYMLINKS fallback value - lib/fileutils: fix unused parameter warnings without SYS_openat2 - libmount: add missing fileutils.h include to hook_idmap.c - libmount: add mnt_open_tree() helper for safe tree opening - libmount: pin source path with openat2() for restricted users (bsc#1275441, bsc#1278347, CVE-2026-78410) - libmount: restrict source path canonicalization for non-root users (bsc#1275441, bsc#1278347, CVE-2026-78410) - libmount: skip post-mount hooks after failed mount helper (bsc#1275441, bsc#1278349, CVE-2026-76642) - libmount: use USE_LIBMOUNT_MOUNTFD_SUPPORT for idmap hook - nsenter: close cgroup.procs fd after join to prevent authority leak (bsc#1275441, bsc#1278348, CVE-2026-78408) - nsenter, unshare: add O_CLOEXEC to all open() calls (bsc#1275441, bsc#1278348, CVE-2026-78408) - wall, write: sanitize hostname in banner header (bsc#1275441) - Add missing function. (bsc#1275441) - ipcutils: Prevent using uninitialized variable (bsc#1268886) - BREAKING CHANGE: Paths must always be canonicalized for unprivileged users to ensure safe target resolution. X-mount.nocanonicalize is ignored for them. - INCOMAPTIBLE CHANGE (linux < 6.15): X-mount.subdir: The safe detached subdirectory is no more supported for unprivileged users for safety reasons. - liblastlog2: Wait on busy SQLite connections (bsc#1268886). - libmount: Fix subvolid buffer overflow in get_btrfs_fs_root (bsc#1268886). - libblkid: Fix use-after-free in nested partition probing (bsc#1269583, bsc#1268886, CVE-2026-13595) - libmount: fix SUID bypass via LIBMOUNT_FORCE_MOUNT2 and legacy mount path (bsc#1268886, CVE-2026-53614, GHSA-67r7-8m5w-22wx). - fileutils: add ul_open_no_symlinks() needed by other patches (bsc#1268886). - libmount: add fd_target to context for TOCTOU race condition prevention (bsc#1268886, CVE-2026-53613, GHSA-8gj5-72r3-428g). - libmount: ignore X-mount.nocanonicalize for restricted users - libmount: use fd-based fchownat/chmod in hook_owner (bsc#1268886, CVE-2026-53612, GHSA-g8wm-75wr-g2vh). - libmount: restrict X-mount.subdir for non-root (bsc#1268886). - libmount: use fd_target in hook_idmap for move_mount() - libmount: add mount ID verification and man page TOCTOU note - loopdev: use openat2(RESOLVE_NO_SYMLINKS) for backing file (bsc#1268886#c2, bsc#1261606). - Ignore pam-config error that prevents update failure if common* pam configuration is not symlink to common-*-pc (bsc#1270219).

A flaw was found in the libblkid library of util-linux. During nested partition probing, the BSD, Minix, Solaris x86, and UnixWare partition probers cache a raw pointer to a parent partition entry in a dynamically allocated array. When subsequent partition additions cause the array to be reallocated, this pointer becomes stale, leading to a heap use-after-free read. An attacker who can present a crafted block device image (for example, via USB insertion or a loop-mounted disk image) can trigger this flaw without user interaction, as libblkid is invoked automatically by udev/udisks as root on block-device hot-plug events. This could lead to limited information disclosure or denial of service.