CVE-2024-41012

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: filelock: Elimina bloqueos de manera confiable cuando se detecta fcntl/close race Cuando fcntl_setlk() corre con close(), elimina el bloqueo creado con do_lock_file_wait(). Sin embargo, los LSM pueden permitir el primer do_lock_file_wait() que creó el bloqueo y al mismo tiempo negar el segundo do_lock_file_wait() que intenta eliminar el bloqueo. Por separado, posix_lock_file() también podría no eliminar un bloqueo debido a un fallo en la asignación de GFP_KERNEL (al dividir un rango por la mitad). Después de que se haya activado el error, se producirán lecturas de use-after-free en lock_get_status() cuando el espacio de usuario lea /proc/locks. Es probable que esto se pueda usar para leer memoria del kernel arbitraria, pero no puede dañar la memoria del kernel. Solucionelo llamando a locks_remove_posix() en su lugar, que está diseñado para deshacerse de manera confiable de los bloqueos POSIX asociados con el archivo dado y files_struct y también lo usa filp_flush().

In the Linux kernel, the following vulnerability has been resolved: filelock: Remove locks reliably when fcntl/close race is detected When fcntl_setlk() races with close(), it removes the created lock with do_lock_file_wait(). However, LSMs can allow the first do_lock_file_wait() that created the lock while denying the second do_lock_file_wait() that tries to remove the lock. Separately, posix_lock_file() could also fail to remove a lock due to GFP_KERNEL allocation failure (when splitting a range in the middle). After the bug has been triggered, use-after-free reads will occur in lock_get_status() when userspace reads /proc/locks. This can likely be used to read arbitrary kernel memory, but can't corrupt kernel memory. Fix it by calling locks_remove_posix() instead, which is designed to reliably get rid of POSIX locks associated with the given file and files_struct and is also used by filp_flush().

It was discovered that the CIFS network file system implementation in the Linux kernel did not properly validate certain SMB messages, leading to an out-of-bounds read vulnerability. An attacker could use this to cause a denial of service or possibly expose sensitive information. Supraja Sridhara, Benedict Schlüter, Mark Kuhne, Andrin Bertschi, and Shweta Shinde discovered that the Confidential Computing framework in the Linux kernel for x86 platforms did not properly handle 32-bit emulation on TDX and SEV. An attacker with access to the VMM could use this to cause a denial of service or possibly execute arbitrary code.