From 6040e57658eee6eb1315a26119101ca832d1f854 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Fri, 19 Aug 2016 12:47:01 -0700 Subject: [PATCH] Make the hardened user-copy code depend on having a hardened allocator The kernel test robot reported a usercopy failure in the new hardened sanity checks, due to a page-crossing copy of the FPU state into the task structure. This happened because the kernel test robot was testing with SLOB, which doesn't actually do the required book-keeping for slab allocations, and as a result the hardening code didn't realize that the task struct allocation was one single allocation - and the sanity checks fail. Since SLOB doesn't even claim to support hardening (and you really shouldn't use it), the straightforward solution is to just make the usercopy hardening code depend on the allocator supporting it. Reported-by: kernel test robot Cc: Kees Cook Signed-off-by: Linus Torvalds --- security/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/security/Kconfig b/security/Kconfig index df28f2b6f3e1..da10d9b573a4 100644 --- a/security/Kconfig +++ b/security/Kconfig @@ -136,6 +136,7 @@ config HAVE_ARCH_HARDENED_USERCOPY config HARDENED_USERCOPY bool "Harden memory copies between kernel and userspace" depends on HAVE_ARCH_HARDENED_USERCOPY + depends on HAVE_HARDENED_USERCOPY_ALLOCATOR select BUG help This option checks for obviously wrong memory regions when -- 2.20.1