Overview CVE-2025-40235 describes a vulnerability in the Btrfs filesystem implementation within the Linux kernel. This flaw can potentially lead to a NULL pointer dereference, resulting in a kernel panic and system crash. The vulnerability stems from improper error handling during the initialization of the Btrfs filesystem’s internal data structures. Specifically, if memory allocation fails during the initial setup, a cleanup routine attempts to access uninitialized memory, triggering the NULL pointer dereference. Technical Details The vulnerability resides in the btrfs_check_leaked_roots() function within the fs/btrfs/disk-io.c file. The issue occurs when either fs_info->super_copy or fs_info->super_for_commit fail to allocate memory within the btrfs_get_tree_subvol() function.…

Overview CVE-2025-40234 describes a vulnerability in the Linux kernel, specifically within the `alienware-wmi-wmax` driver. This driver is responsible for handling WMI (Windows Management Instrumentation) events on Alienware laptops. The vulnerability arises from a potential NULL pointer dereference in the driver’s sleep handlers when the Alienware Command Center (AWCC) interface is not initialized. A patch has been implemented to address this issue. Technical Details The core issue is that devices without the AWCC interface do not properly initialize the `awcc` variable within the `alienware-wmi-wmax` driver. Consequently, the sleep handlers attempt to dereference a NULL pointer, leading to a kernel crash or…

Overview CVE-2025-40233 identifies a vulnerability in the Linux kernel’s OCFS2 (Oracle Cluster File System version 2) file system. Specifically, the extent map cache could become stale after extents are moved or defragmented. This stale data can lead to subsequent operations operating on outdated extent flags, triggering a kernel panic (BUG_ON) due to inconsistencies between cached and on-disk data. Technical Details The vulnerability arises from a scenario involving reflinked extents, file range copies, and extent movement. The specific sequence of events leading to the issue is as follows: copy_file_range() creates a reflinked extent with the OCFS2_EXT_REFCOUNTED flag set. An ioctl(FITRIM) operation…

Overview CVE-2025-40232 describes a type confusion vulnerability in the Linux kernel, specifically affecting the implementation of RV (Runtime Verification) monitors. This issue arises from inconsistencies in how the `enabled_monitors_seq_ops` callbacks handle iterators. Some callbacks incorrectly treated the iterator as `struct rv_monitor *` while others treated it as `struct list_head *`, leading to potential crashes due to incorrect type casting. Technical Details The vulnerability lies within the code responsible for managing enabled RV monitors in the Linux kernel. The `enabled_monitors_seq_ops` structure defines a set of sequence operations used for iterating through the list of enabled monitors. Due to inconsistencies in the…

Overview CVE-2025-40231 describes a resolved lock inversion vulnerability in the Linux kernel’s Virtual Socket (vsock) implementation. This flaw could lead to a deadlock, potentially causing a denial-of-service condition. The vulnerability was discovered by Syzbot and addressed in recent kernel updates. Technical Details The vulnerability stems from a potential lock inversion deadlock between vsock_register_mutex and sk_lock-AF_VSOCK when vsock_linger() is called. Specifically, the issue arises in the vsock_assign_transport() function. The vulnerability was introduced by commit 687aa0c5581b (“vsock: Fix transport_* TOCTOU”). This commit added vsock_register_mutex locking in vsock_assign_transport() around the transport->release() call, which can trigger vsock_linger(). vsock_assign_transport() can be invoked while holding sk_lock.…

Overview CVE-2025-40230 is a vulnerability in the Linux kernel that can cause a kernel panic when handling memory errors within Transparent Huge Pages (THPs). This occurs specifically on x86 servers when memory error injection is performed on a THP mapped to userspace. Instead of the expected behavior of terminating the affected process, the kernel crashes, leading to a denial-of-service condition. Technical Details The root cause of the panic lies in how the kernel attempts to handle Machine Check Exceptions (#MC) triggered by memory failures in userspace mapped THPs. The handling process involves splitting the THP. The splitting process uses `try_to_map_unused_to_zeropage()`…

Overview CVE-2025-40229 describes a memory leak vulnerability discovered and fixed in the Linux kernel’s DAMON (Data Access Monitoring) subsystem. This vulnerability arises from incomplete cleanup during the destruction of a DAMON scheme, potentially leading to resource exhaustion over time. This article provides a detailed analysis of the vulnerability, its possible impact, and the necessary mitigation steps. Technical Details The vulnerability resides within the damon_destroy_scheme() function in the DAMON core. Prior to the fix, this function was only cleaning up the filter list associated with a DAMON scheme but neglecting to free the ops_filter. This oversight resulted in memory allocated to…

Overview CVE-2025-40228 describes a vulnerability discovered in the Linux kernel’s DAMON (Data Access Monitoring) sysfs interface. This vulnerability arises from a missing allocation failure check during the creation of a damon_ctx object used for validating DAMON parameters. Without this check, a failed allocation could lead to a null pointer dereference and potentially other unexpected behavior. The fix addresses the memory leak and the lack of allocation failure handling. Technical Details The DAMON sysfs interface allows userspace to dynamically update DAMON parameters. To ensure the validity of these parameters, the kernel dynamically allocates a damon_ctx object to perform a test commit.…

Overview CVE-2025-40227 identifies a memory leak vulnerability found in the Data Access Monitoring (DAMON) subsystem of the Linux kernel. The vulnerability arises from the improper deallocation of memory used for testing online DAMON parameters commit inputs. This article provides a detailed analysis of the vulnerability, its potential impact, and the steps taken to mitigate it. Technical Details The issue stems from the fact that the damon_ctx (DAMON context) used for testing online DAMON parameters commit inputs was only deallocated when the test failed. This meant that every successful online DAMON parameters commit would result in a memory leak, as the…

Overview This article delves into CVE-2025-40226, a vulnerability identified in the Linux kernel. This issue arises within the ARM System Control and Management Interface (SCMI) framework, specifically related to the handling of debug initialization failures. The patch addresses a scenario where the SCMI debug subsystem fails to initialize, leading to a missing debug root and a NULL descriptor. The fix ensures that SCMI debug helpers appropriately handle this fault condition when maintaining metrics counters. Technical Details The ARM SCMI provides a standardized interface for managing various system-level functions, including power management, clock control, and debug capabilities. The vulnerability occurs because,…