From afcc90f8621e289cd082ba97900e76f01afe778c Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 10 Jan 2018 15:17:01 -0800 Subject: usercopy: WARN() on slab cache usercopy region violations This patch adds checking of usercopy cache whitelisting, and is modified from Brad Spengler/PaX Team's PAX_USERCOPY whitelisting code in the last public patch of grsecurity/PaX based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. The SLAB and SLUB allocators are modified to WARN() on all copy operations in which the kernel heap memory being modified falls outside of the cache's defined usercopy region. Based on an earlier patch from David Windsor. Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Joonsoo Kim Cc: Andrew Morton Cc: Laura Abbott Cc: Ingo Molnar Cc: Mark Rutland Cc: linux-mm@kvack.org Cc: linux-xfs@vger.kernel.org Signed-off-by: Kees Cook --- include/linux/uaccess.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/uaccess.h') diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h index 38b6442dc569..efe79c1cdd47 100644 --- a/include/linux/uaccess.h +++ b/include/linux/uaccess.h @@ -274,6 +274,8 @@ extern long strncpy_from_unsafe(char *dst, const void *unsafe_addr, long count); #endif #ifdef CONFIG_HARDENED_USERCOPY +void usercopy_warn(const char *name, const char *detail, bool to_user, + unsigned long offset, unsigned long len); void __noreturn usercopy_abort(const char *name, const char *detail, bool to_user, unsigned long offset, unsigned long len); -- cgit v1.2.3-59-g8ed1b