Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1738141

[PATCH 09/10] x86/fpu: Use validate_xstate_header() to validate the xstate_header in copy_user_to_xstate()

From Ingo Molnar <mingo@kernel.org>
Newsgroups linux.kernel
Subject [PATCH 09/10] x86/fpu: Use validate_xstate_header() to validate the xstate_header in copy_user_to_xstate()
Date 2017-09-24 13:00 +0200
Message-ID <utcNH-7Gh-9@gated-at.bofh.it> (permalink)
References <utcNH-7Gh-3@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw

From: Eric Biggers <ebiggers@google.com>

Tighten the checks in copy_user_to_xstate().

Signed-off-by: Eric Biggers <ebiggers@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kevin Hao <haokexin@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Halcrow <mhalcrow@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Cc: Yu-cheng Yu <yu-cheng.yu@intel.com>
Cc: kernel-hardening@lists.openwall.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/kernel/fpu/xstate.c | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index b6d78b78b5c2..f1d5476c9022 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -1188,16 +1188,15 @@ int copy_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf)
 }
 
 /*
- * Convert from a ptrace standard-format user-space buffer to kernel XSAVES format
- * and copy to the target thread. This is called from xstateregs_set() and
- * there we check the CPU has XSAVES and a whole standard-sized buffer
- * exists.
+ * Convert from a ptrace or sigreturn standard-format user-space buffer to
+ * kernel XSAVES format and copy to the target thread. This is called from
+ * xstateregs_set(), as well as potentially from the sigreturn() and
+ * rt_sigreturn() system calls.
  */
 int copy_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf)
 {
 	unsigned int offset, size;
 	int i;
-	u64 allowed_features;
 	struct xstate_header hdr;
 
 	offset = offsetof(struct xregs_state, header);
@@ -1206,12 +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;
 
-	/*
-	 * Reject if the user sets any disabled or supervisor features:
-	 */
-	allowed_features = xfeatures_mask & ~XFEATURE_MASK_SUPERVISOR;
-
-	if (hdr.xfeatures & ~allowed_features)
+	if (validate_xstate_header(&hdr))
 		return -EINVAL;
 
 	for (i = 0; i < XFEATURE_MAX; i++) {
-- 
2.11.0

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH 00/10] x86/fpu: Split up "x86/fpu: Tighten validation of user-supplied xstate_header" Ingo Molnar <mingo@kernel.org> - 2017-09-24 13:00 +0200
  [PATCH 02/10] x86/fpu: Use validate_xstate_header() to validate the xstate_header in xstateregs_set() Ingo Molnar <mingo@kernel.org> - 2017-09-24 13:00 +0200
    [tip:x86/fpu] x86/fpu: Use validate_xstate_header() to validate the  xstate_header in xstateregs_set() tip-bot for Eric Biggers <tipbot@zytor.com> - 2017-09-26 10:50 +0200
  [PATCH 09/10] x86/fpu: Use validate_xstate_header() to validate the xstate_header in copy_user_to_xstate() Ingo Molnar <mingo@kernel.org> - 2017-09-24 13:00 +0200
    [tip:x86/fpu] x86/fpu: Use validate_xstate_header() to validate the  xstate_header in copy_user_to_xstate() tip-bot for Eric Biggers <tipbot@zytor.com> - 2017-09-26 10:50 +0200
  [PATCH 10/10] x86/fpu: Use using_compacted_format() instead of open coded X86_FEATURE_XSAVES Ingo Molnar <mingo@kernel.org> - 2017-09-24 13:10 +0200
    [tip:x86/fpu] x86/fpu: Use using_compacted_format() instead of open  coded X86_FEATURE_XSAVES tip-bot for Eric Biggers <tipbot@zytor.com> - 2017-09-26 10:50 +0200
  [PATCH 03/10] x86/fpu: Use validate_xstate_header() to validate the xstate_header in sanitize_restored_xstate() Ingo Molnar <mingo@kernel.org> - 2017-09-24 13:10 +0200
    Re: [PATCH 03/10] x86/fpu: Use validate_xstate_header() to validate  the xstate_header in sanitize_restored_xstate() Eric Biggers <ebiggers3@gmail.com> - 2017-09-24 21:00 +0200
      Re: [PATCH 03/10] x86/fpu: Use validate_xstate_header() to validate  the xstate_header in sanitize_restored_xstate() Ingo Molnar <mingo@kernel.org> - 2017-09-24 21:10 +0200
        Re: [PATCH 03/10] x86/fpu: Use validate_xstate_header() to validate  the xstate_header in sanitize_restored_xstate() Eric Biggers <ebiggers3@gmail.com> - 2017-09-24 22:10 +0200
          Re: [PATCH 03/10] x86/fpu: Use validate_xstate_header() to validate  the xstate_header in sanitize_restored_xstate() Ingo Molnar <mingo@kernel.org> - 2017-09-25 08:10 +0200
          Re: [PATCH 03/10] x86/fpu: Use validate_xstate_header() to validate  the xstate_header in sanitize_restored_xstate() Ingo Molnar <mingo@kernel.org> - 2017-09-25 08:20 +0200
            Re: [PATCH 03/10] x86/fpu: Use validate_xstate_header() to validate  the xstate_header in sanitize_restored_xstate() Eric Biggers <ebiggers3@gmail.com> - 2017-09-25 09:30 +0200
              Re: [PATCH 03/10] x86/fpu: Use validate_xstate_header() to validate  the xstate_header in sanitize_restored_xstate() Ingo Molnar <mingo@kernel.org> - 2017-09-25 09:40 +0200
    [tip:x86/fpu] x86/fpu: Use validate_xstate_header() to validate the  xstate_header in __fpu__restore_sig() tip-bot for Eric Biggers <tipbot@zytor.com> - 2017-09-26 10:50 +0200
  [PATCH 07/10] x86/fpu: Copy the full header in copy_user_to_xstate() Ingo Molnar <mingo@kernel.org> - 2017-09-24 13:10 +0200
    [tip:x86/fpu] x86/fpu: Copy the full header in  copy_user_to_xstate() tip-bot for Eric Biggers <tipbot@zytor.com> - 2017-09-26 10:50 +0200
  [PATCH 01/10] x86/fpu: Introduce validate_xstate_header() Ingo Molnar <mingo@kernel.org> - 2017-09-24 13:10 +0200
    [tip:x86/fpu] x86/fpu: Introduce validate_xstate_header() tip-bot for Eric Biggers <tipbot@zytor.com> - 2017-09-26 10:50 +0200
  [PATCH 08/10] x86/fpu: Eliminate the 'xfeatures' local variable in copy_user_to_xstate() Ingo Molnar <mingo@kernel.org> - 2017-09-24 13:10 +0200
    [tip:x86/fpu] x86/fpu: Eliminate the 'xfeatures' local variable in  copy_user_to_xstate() tip-bot for Eric Biggers <tipbot@zytor.com> - 2017-09-26 10:50 +0200
  [PATCH 04/10] x86/fpu: Copy the full state_header in copy_kernel_to_xstate() Ingo Molnar <mingo@kernel.org> - 2017-09-24 13:10 +0200
    [tip:x86/fpu] x86/fpu: Copy the full state_header in  copy_kernel_to_xstate() tip-bot for Eric Biggers <tipbot@zytor.com> - 2017-09-26 10:50 +0200
  [PATCH 06/10] x86/fpu: Use validate_xstate_header() to validate the xstate_header in copy_kernel_to_xstate() Ingo Molnar <mingo@kernel.org> - 2017-09-24 13:10 +0200
    [tip:x86/fpu] x86/fpu: Use validate_xstate_header() to validate the  xstate_header in copy_kernel_to_xstate() tip-bot for Eric Biggers <tipbot@zytor.com> - 2017-09-26 10:50 +0200
  Re: [PATCH 00/10] x86/fpu: Split up "x86/fpu: Tighten validation of  user-supplied xstate_header" Linus Torvalds <torvalds@linux-foundation.org> - 2017-09-24 20:10 +0200
    Re: [PATCH 00/10] x86/fpu: Split up "x86/fpu: Tighten validation of  user-supplied xstate_header" Ingo Molnar <mingo@kernel.org> - 2017-09-24 21:10 +0200

csiph-web