As mentioned before, the patch was too big and too complex, and I've split it
up into 10 smaller, bisectable patches:
Eric Biggers (10):
x86/fpu: Introduce validate_xstate_header()
x86/fpu: Use validate_xstate_header() to validate the xstate_header in
xstateregs_set()
x86/fpu: Use validate_xstate_header() to validate the xstate_header in
sanitize_restored_xstate()
x86/fpu: Copy the full state_header in copy_kernel_to_xstate()
x86/fpu: Eliminate the 'xfeatures' local variable in copy_kernel_to_xstate()
x86/fpu: Use validate_xstate_header() to validate the xstate_header in
copy_kernel_to_xstate()
x86/fpu: Copy the full header in copy_user_to_xstate()
x86/fpu: Eliminate the 'xfeatures' local variable in copy_user_to_xstate()
x86/fpu: Use validate_xstate_header() to validate the xstate_header in
copy_user_to_xstate()
x86/fpu: Use using_compacted_format() instead of open coded X86_FEATURE_XSAVES
arch/x86/include/asm/fpu/xstate.h | 4 ++++
arch/x86/kernel/fpu/regset.c | 21 ++++++-----------
arch/x86/kernel/fpu/signal.c | 17 ++++++-------
arch/x86/kernel/fpu/xstate.c | 76
+++++++++++++++++++++++++++++++++--------------------------
4 files changed, 63 insertions(+), 55 deletions(-)
I kept the attribution in place, because the end result is almost the same.
Below is the interdiff from the original version, I uninlined
validate_xstate_header(),
because it's way too large to be inlined everywhere, plus I removed a couple of
spurious "!= 0" patterns.
The latest x86/fpu bits can be found in -tip:
git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git master
git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git WIP.x86/fpu
Thanks,
Ingo
===
include/asm/fpu/xstate.h | 23 +----------------------
kernel/fpu/xstate.c | 28 ++++++++++++++++++++++++++--
2 files changed, 27 insertions(+), 24 deletions(-)
diff --git a/arch/x86/include/asm/fpu/xstate.h
b/arch/x86/include/asm/fpu/xstate.h
index 3d79d0ee4d30..83fee2469eb7 100644
--- a/arch/x86/include/asm/fpu/xstate.h
+++ b/arch/x86/include/asm/fpu/xstate.h
@@ -54,27 +54,6 @@ int copy_kernel_to_xstate(struct xregs_state *xsave, const
void *kbuf);
int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf);
/* Validate an xstate header supplied by userspace (ptrace or sigreturn) */
-static inline int validate_xstate_header(const struct xstate_header *hdr)
-{
- /* No unknown or supervisor features may be set */
- if (hdr->xfeatures & (~xfeatures_mask | XFEATURE_MASK_SUPERVISOR))
- return -EINVAL;
-
- /* Userspace must use the uncompacted format */
- if (hdr->xcomp_bv)
- return -EINVAL;
-
- /*
- * If 'reserved' is shrunken to add a new field, make sure to validate
- * that new field here!
- */
- BUILD_BUG_ON(sizeof(hdr->reserved) != 48);
-
- /* No reserved bits may be set */
- if (memchr_inv(hdr->reserved, 0, sizeof(hdr->reserved)))
- return -EINVAL;
-
- return 0;
-}
+extern int validate_xstate_header(const struct xstate_header *hdr);
#endif
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 7ebd1a0811b6..f1d5476c9022 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -483,6 +483,30 @@ int using_compacted_format(void)
return boot_cpu_has(X86_FEATURE_XSAVES);
}
+/* Validate an xstate header supplied by userspace (ptrace or sigreturn) */
+int validate_xstate_header(const struct xstate_header *hdr)
+{
+ /* No unknown or supervisor features may be set */
+ if (hdr->xfeatures & (~xfeatures_mask | XFEATURE_MASK_SUPERVISOR))
+ return -EINVAL;
+
+ /* Userspace must use the uncompacted format */
+ if (hdr->xcomp_bv)
+ return -EINVAL;
+
+ /*
+ * If 'reserved' is shrunken to add a new field, make sure to validate
+ * that new field here!
+ */
+ BUILD_BUG_ON(sizeof(hdr->reserved) != 48);
+
+ /* No reserved bits may be set */
+ if (memchr_inv(hdr->reserved, 0, sizeof(hdr->reserved)))
+ return -EINVAL;
+
+ return 0;
+}
+
static void __xstate_dump_leaves(void)
{
int i;
@@ -1127,7 +1151,7 @@ int copy_kernel_to_xstate(struct xregs_state *xsave,
const void *kbuf)
memcpy(&hdr, kbuf + offset, size);
- if (validate_xstate_header(&hdr) != 0)
+ if (validate_xstate_header(&hdr))
return -EINVAL;
for (i = 0; i < XFEATURE_MAX; i++) {
@@ -1181,7 +1205,7 @@ int copy_user_to_xstate(struct xregs_state *xsave, const
void __user *ubuf)
if (__copy_from_user(&hdr, ubuf + offset, size))
return -EFAULT;
- if (validate_xstate_header(&hdr) != 0)
+ if (validate_xstate_header(&hdr))
return -EINVAL;
for (i = 0; i < XFEATURE_MAX; i++) {
