diff options
| author | Kees Cook <keescook@chromium.org> | 2017-08-16 22:26:03 +0200 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2018-01-15 21:08:05 +0100 |
| commit | f7d83c1cf3c77ae45876792aee5285ae970413ac (patch) | |
| tree | 885c783c6717503e5935338a0fe9f4387b52a9ec /arch | |
| parent | fork: Provide usercopy whitelisting for task_struct (diff) | |
| download | linux-f7d83c1cf3c77ae45876792aee5285ae970413ac.tar.xz linux-f7d83c1cf3c77ae45876792aee5285ae970413ac.zip | |
x86: Implement thread_struct whitelist for hardened usercopy
This whitelists the FPU register state portion of the thread_struct for
copying to userspace, instead of the default entire struct. This is needed
because FPU register state is dynamically sized, so it doesn't bypass the
hardened usercopy checks.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Rik van Riel <riel@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/Kconfig | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/processor.h | 8 |
2 files changed, 9 insertions, 0 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 8eed3f94bfc7..9ac4ac1a856b 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -116,6 +116,7 @@ config X86 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT select HAVE_ARCH_SECCOMP_FILTER + select HAVE_ARCH_THREAD_STRUCT_WHITELIST select HAVE_ARCH_TRACEHOOK select HAVE_ARCH_TRANSPARENT_HUGEPAGE select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index cc16fa882e3e..2b037b7fe0eb 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -492,6 +492,14 @@ struct thread_struct { */ }; +/* Whitelist the FPU state from the task_struct for hardened usercopy. */ +static inline void arch_thread_struct_whitelist(unsigned long *offset, + unsigned long *size) +{ + *offset = offsetof(struct thread_struct, fpu.state); + *size = fpu_kernel_xstate_size; +} + /* * Thread-synchronous status. * |