From: Ingo Molnar <mingo@kernel.org>
To: linux-kernel@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>,
Eric Biggers <ebiggers3@gmail.com>,
Andy Lutomirski <luto@amacapital.net>,
Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
Fenghua Yu <fenghua.yu@intel.com>,
"H . Peter Anvin" <hpa@zytor.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Oleg Nesterov <oleg@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Rik van Riel <riel@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Yu-cheng Yu <yu-cheng.yu@intel.com>
Subject: [PATCH 00/10] x86/fpu: Split up "x86/fpu: Tighten validation of user-supplied xstate_header"
Date: Sun, 24 Sep 2017 12:59:03 +0200 [thread overview]
Message-ID: <20170924105913.9157-1-mingo@kernel.org> (raw)
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++) {
next reply other threads:[~2017-09-24 10:59 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-24 10:59 Ingo Molnar [this message]
2017-09-24 10:59 ` [PATCH 01/10] x86/fpu: Introduce validate_xstate_header() Ingo Molnar
2017-09-26 8:34 ` [tip:x86/fpu] " tip-bot for Eric Biggers
2017-09-24 10:59 ` [PATCH 02/10] x86/fpu: Use validate_xstate_header() to validate the xstate_header in xstateregs_set() Ingo Molnar
2017-09-26 8:34 ` [tip:x86/fpu] " tip-bot for Eric Biggers
2017-09-24 10:59 ` [PATCH 03/10] x86/fpu: Use validate_xstate_header() to validate the xstate_header in sanitize_restored_xstate() Ingo Molnar
2017-09-24 18:51 ` Eric Biggers
2017-09-24 19:02 ` Ingo Molnar
2017-09-24 20:08 ` Eric Biggers
2017-09-25 6:07 ` Ingo Molnar
2017-09-25 6:14 ` Ingo Molnar
2017-09-25 7:20 ` Eric Biggers
2017-09-25 7:30 ` Ingo Molnar
2017-09-26 8:35 ` [tip:x86/fpu] x86/fpu: Use validate_xstate_header() to validate the xstate_header in __fpu__restore_sig() tip-bot for Eric Biggers
2017-09-24 10:59 ` [PATCH 04/10] x86/fpu: Copy the full state_header in copy_kernel_to_xstate() Ingo Molnar
2017-09-26 8:35 ` [tip:x86/fpu] " tip-bot for Eric Biggers
2017-09-24 10:59 ` [PATCH 05/10] x86/fpu: Eliminate the 'xfeatures' local variable " Ingo Molnar
2017-09-26 8:35 ` [tip:x86/fpu] " tip-bot for Eric Biggers
2017-09-24 10:59 ` [PATCH 06/10] x86/fpu: Use validate_xstate_header() to validate the xstate_header " Ingo Molnar
2017-09-26 8:36 ` [tip:x86/fpu] " tip-bot for Eric Biggers
2017-09-24 10:59 ` [PATCH 07/10] x86/fpu: Copy the full header in copy_user_to_xstate() Ingo Molnar
2017-09-26 8:36 ` [tip:x86/fpu] " tip-bot for Eric Biggers
2017-09-24 10:59 ` [PATCH 08/10] x86/fpu: Eliminate the 'xfeatures' local variable " Ingo Molnar
2017-09-26 8:37 ` [tip:x86/fpu] " tip-bot for Eric Biggers
2017-09-24 10:59 ` [PATCH 09/10] x86/fpu: Use validate_xstate_header() to validate the xstate_header " Ingo Molnar
2017-09-26 8:37 ` [tip:x86/fpu] " tip-bot for Eric Biggers
2017-09-24 10:59 ` [PATCH 10/10] x86/fpu: Use using_compacted_format() instead of open coded X86_FEATURE_XSAVES Ingo Molnar
2017-09-26 8:37 ` [tip:x86/fpu] " tip-bot for Eric Biggers
2017-09-24 18:04 ` [PATCH 00/10] x86/fpu: Split up "x86/fpu: Tighten validation of user-supplied xstate_header" Linus Torvalds
2017-09-24 19:01 ` Ingo Molnar
2017-09-26 16:28 ` [RFC GIT PULL] x86 FPU fixes and cleanups Ingo Molnar
2017-09-26 18:17 ` Linus Torvalds
2017-09-27 7:40 ` [RFC GIT PULL, v2] " Ingo Molnar
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