Date: Tue, 19 Jan 2016 10:08:34 -0800 From: Kees Cook <keescook@...omium.org> To: Ingo Molnar <mingo@...hat.com> Cc: Kees Cook <keescook@...omium.org>, Andy Lutomirski <luto@...capital.net>, "H. Peter Anvin" <hpa@...or.com>, Michael Ellerman <mpe@...erman.id.au>, Mathias Krause <minipli@...glemail.com>, Thomas Gleixner <tglx@...utronix.de>, x86@...nel.org, Arnd Bergmann <arnd@...db.de>, PaX Team <pageexec@...email.hu>, Emese Revfy <re.emese@...il.com>, kernel-hardening@...ts.openwall.com, linux-kernel@...r.kernel.org, linux-arch <linux-arch@...r.kernel.org> Subject: [PATCH v4 0/8] introduce post-init read-only memory One of the easiest ways to protect the kernel from attack is to reduce the internal attack surface exposed when a "write" flaw is available. By making as much of the kernel read-only as possible, we reduce the attack surface. Many things are written to only during __init, and never changed again. These cannot be made "const" since the compiler will do the wrong thing (we do actually need to write to them). Instead, move these items into a memory region that will be made read-only during mark_rodata_ro() which happens after all kernel __init code has finished. This introduces __ro_after_init as a way to mark such memory, and uses it on the x86 vDSO to kill an extant kernel exploitation method. Also adds a new kernel parameter to help debug future use and adds an lkdtm test to check the results. -Kees v4: - rebased v3: - conslidated mark_rodata_ro() - make CONFIG_DEBUG_RODATA always enabled on x86, mingo - enhanced strtobool and potential callers to use "on"/"off" - use strtobool for rodata= param, gregkh v2: - renamed __read_only to __ro_after_init
Powered by blists - more mailing lists
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.