CVE-2023-52757

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: smb: client: corrige un posible punto muerto al liberar mids. Todos los llamadores de release_mid() parecen tener una referencia de @mid, por lo que no hay necesidad de llamar a kref_put(&mid->refcount, __release_mid ) en @servidor->mid_lock spinlock. Si no lo hacen, de todos modos se habría producido un error de use after free. Al deshacerse de dicho bloqueo de giro, también se soluciona un posible punto muerto como se muestra a continuación CPU 0 CPU 1 -------------------------------- ---------------------------------- cifs_demultiplex_thread() cifs_debug_data_proc_show() release_mid() spin_lock(&servidor->mid_lock) ; spin_lock(&cifs_tcp_ses_lock) spin_lock(&servidor->mid_lock) __release_mid() smb2_find_smb_tcon() spin_lock(&cifs_tcp_ses_lock) *punto muerto*

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix potential deadlock when releasing mids All release_mid() callers seem to hold a reference of @mid so there is no need to call kref_put(&mid->refcount, __release_mid) under @server->mid_lock spinlock. If they don't, then an use-after-free bug would have occurred anyways. By getting rid of such spinlock also fixes a potential deadlock as shown below CPU 0 CPU 1 ------------------------------------------------------------------ cifs_demultiplex_thread() cifs_debug_data_proc_show() release_mid() spin_lock(&server->mid_lock); spin_lock(&cifs_tcp_ses_lock) spin_lock(&server->mid_lock) __release_mid() smb2_find_smb_tcon() spin_lock(&cifs_tcp_ses_lock) *deadlock*

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.