A flaw was found in the Linux kernel's TUN/TAP functionality. This issue could allow a local user to bypass network filters and gain unauthorized access to some resources. The original patches fixing CVE-2023-1076 are incorrect or incomplete. The problem is that the following upstream commits - a096ccca6e50 ("tun: tun_chr_open(): correctly initialize socket uid"), - 66b2c338adce ("tap: tap_open(): correctly initialize socket uid"), pass "inode->i_uid" to sock_init_data_uid() as the last parameter and that turns out to not be accurate.
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.