CVE-2024-26689

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: ceph: evita el use-after-free en encode_cap_msg() En fs/ceph/caps.c, en encode_cap_msg(), KASAN detectó el error "use after free" en este línea - 'ceph_buffer_get(arg->xattr_buf);'. Esto implica que antes de que el recuento pudiera incrementarse aquí, fue liberado. En el mismo archivo, en "handle_cap_grant()", el refcount se reduce en esta línea: 'ceph_buffer_put(ci->i_xattrs.blob);'. Parece que se produjo una ejecución y la última línea liberó el recurso antes de que la primera línea pudiera incrementarlo. __send_cap() llama a encode_cap_msg() y ceph_check_caps() llama a __send_cap() después de llamar a __prep_cap(). __prep_cap() es donde arg->xattr_buf se asigna a ci->i_xattrs.blob. Este es el punto donde se debe aumentar el recuento para evitar el error "use after free".

In the Linux kernel, the following vulnerability has been resolved: ceph: prevent use-after-free in encode_cap_msg() In fs/ceph/caps.c, in encode_cap_msg(), "use after free" error was caught by KASAN at this line - 'ceph_buffer_get(arg->xattr_buf);'. This implies before the refcount could be increment here, it was freed. In same file, in "handle_cap_grant()" refcount is decremented by this line - 'ceph_buffer_put(ci->i_xattrs.blob);'. It appears that a race occurred and resource was freed by the latter line before the former line could increment it. encode_cap_msg() is called by __send_cap() and __send_cap() is called by ceph_check_caps() after calling __prep_cap(). __prep_cap() is where arg->xattr_buf is assigned to ci->i_xattrs.blob. This is the spot where the refcount must be increased to prevent "use after free" error.

Zheng Wang discovered that the Broadcom FullMAC WLAN driver in the Linux kernel contained a race condition during device removal, leading to a use- after-free vulnerability. A physically proximate attacker could possibly use this to cause a denial of service. It was discovered that the ATA over Ethernet driver in the Linux kernel contained a race condition, leading to a use-after-free vulnerability. An attacker could use this to cause a denial of service or possibly execute arbitrary code.