| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally. |
| Heap-based buffer overflow in Microsoft Windows Search Component allows an unauthorized attacker to execute code over a network. |
| Use after free in Windows Universal Disk Format File System Driver (UDFS) allows an authorized attacker to elevate privileges locally. |
| Heap-based buffer overflow in Windows Partition Management Driver allows an authorized attacker to elevate privileges locally. |
| Release of invalid pointer or reference in Windows Kernel allows an authorized attacker to elevate privileges locally. |
| Out-of-bounds read in Windows Local Security Authority Subsystem Service (LSASS) allows an unauthorized attacker to deny service over a network. |
| In the Linux kernel, the following vulnerability has been resolved:
namei: don't reveal overmounted entries in refwalk
In rcuwalk the dentry is validated before it is accepted. step_into()
step_into() rechecks d_seq and __follow_mount_rcu() rechecks mount_lock.
An entry that gets unlinked in between causes the lookup to retry and
miss.
A refwalk doesn't do this. lookup_fast() takes a reference on the hashed
dentry and simply accepts it. So an unlink that happens after the
reference was taken isn't seen by refwalk. That's fine for a simple
file. We just happened to open it before it was unlinked, no problem.
For a mountpoint and specifically a locked mountpoint it very much
isn't. The unlink detaches all mounts and then removes the name. Any
refwalk that hasn't traversed the mounts yet simply reveals the
underlying entry. It's a very narrow window but it can be hit:
reads of a covered file in 60 s, 3 walkers, ~15000 unlinks
no widening 27
that step + 200 us 3741
See the appended patch for a more reliable reproducer.
So check the entry after step_into(). unlink(), rmdir() and rename()
mark the dentry with dont_mount() before they detach the mounts and
remove the dentry.
So a dentry that is marked with DCACHE_CANT_MOUNT and is unhashed by the
time its mounts were looked at is a name that was unlinked under the
refwalk. DCACHE_CANT_MOUNT is read after the mounts were looked up and
it is set before they are detached by detach_mounts(). A refwalk that
missed the mounts will see DCACHE_CANT_MOUNT.
Plain d_unlinked() is fine. A rename takes the dentry off its hash chain
but ___d_drop() leaves d_hash.pprev set. So only __d_drop() and a rename
over the dentry unhash it. The only move that flips IS_ROOT splices in a
disconnected alias. That doesn't have DCACHE_CANT_MOUNT set.
Add the to step_into_slowpath(). ".." and LOOKUP_DOWN may legitimately
land on an unhashed directory. A refwalk that crossed onto a mount has
path.mnt different from nd->path.mnt. A dentry that a filesystem dropped
on its own (d_invalidate(), d_drop()) doesn't have the flag set and is
treated as before.
// SPDX-License-Identifier: GPL-2.0
/*
* unlink_covered: unlink a file that is a mountpoint in a detached copy of
* its mount, against walkers that open it through that copy.
*
* A is a tmpfs with the file f1 (content SECRET_F) and the plain file
* MARK_A. A' is an open_tree(OPEN_TREE_CLONE) copy of A with MARK_A bound
* on A'/f1, held through an O_PATH fd on its root once the tree fd is
* closed. Walkers open f1 through that fd while the driver unlinks A/f1,
* where nothing is mounted on it. A walker may read MARK_A or get ENOENT.
* A read of SECRET_F is a hit: the name was found after its mount was
* gone. The lockless walks use openat2(RESOLVE_CACHED).
*
* usage: unlink_covered [-t seconds] [-w walkers]
*/
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <stdatomic.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <linux/openat2.h>
#ifndef __NR_open_tree
#define __NR_open_tree 428
#endif
#ifndef __NR_move_mount
#define __NR_move_mount 429
#endif
#ifndef __NR_openat2
#define __NR_openat2 437
#endif
#ifndef OPEN_TREE_CLONE
#define OPEN_TREE_CLONE 1
#endif
#ifndef OPEN_TREE_CLOEXEC
#define OPEN_TREE_CLOEXEC O_CLOEXEC
#endif
#ifndef MOVE_MOUNT_F_EMPTY_PATH
#define MOVE_MOUNT_F_EMPTY_PATH 0x00000004
#endif
#define WORK "/tmp/uc"
#define ADIR WORK "/A"
static int duration = 60, nwalkers = 3;
static atomic_int stop, writer_waiting;
static pthread_rwlock_t cur_lock = PTHREAD_RWLOCK_INITIALIZER;
static int cur_fd = -1; /* the root of A', -1 while there is none */
static atomic_long n_unlink, n_walk, n_mark, n_enoent, n_othe
---truncated--- |
| Heap-based buffer overflow in Windows Client-Side Caching (CSC) Service allows an authorized attacker to elevate privileges locally. |
| A flaw was found in Red Hat Advanced Cluster Security for Kubernetes (RHACS). The Central SAML authentication ACS endpoint does not retain used SAML assertion or response identifiers to prevent replay. An attacker who obtains a valid, unexpired signed SAML response can submit it multiple times and receive distinct Central authentication tokens for the mapped identity. |
| Improper access control in Windows Geotag Broker allows an authorized attacker to elevate privileges locally. |
| Weak authentication in Windows Resilient File System (ReFS) Deduplication Service allows an authorized attacker to elevate privileges locally. |
| Untrusted pointer dereference in Windows Core Messaging allows an authorized attacker to elevate privileges locally. |
| Heap-based buffer overflow in Windows Media allows an authorized attacker to elevate privileges locally. |
| Heap-based buffer overflow in Windows Bind Filter Driver allows an authorized attacker to elevate privileges locally. |
| Time-of-check time-of-use (toctou) race condition in Reliable Multicast Transport Driver (RMCAST) allows an authorized attacker to elevate privileges locally. |
| Use after free in Windows Now Playing Session Manager allows an authorized attacker to elevate privileges locally. |
| Use after free in Windows Now Playing Session Manager allows an authorized attacker to elevate privileges locally. |
| Improper privilege management in Python allows an authorized attacker to elevate privileges locally. |
| Use after free in Windows Installer allows an authorized attacker to elevate privileges locally. |
| Stack-based buffer overflow in Microsoft Graphics Component allows an authorized attacker to elevate privileges over a network. |
