From: tip-bot for Eric Biggers <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: tglx@linutronix.de, dvyukov@google.com, mingo@kernel.org,
oleg@redhat.com, riel@redhat.com, yu-cheng.yu@intel.com,
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akpm@linux-foundation.org, luto@amacapital.net,
ebiggers@google.com, luto@kernel.org, ebiggers3@gmail.com
Subject: [tip:x86/fpu] x86/fpu: Use validate_xstate_header() to validate the xstate_header in __fpu__restore_sig()
Date: Tue, 26 Sep 2017 01:35:10 -0700 [thread overview]
Message-ID: <tip-b11e2e18a7fc8eaa3d592c260d50c7129e094ded@git.kernel.org> (raw)
In-Reply-To: <20170924105913.9157-4-mingo@kernel.org>
Commit-ID: b11e2e18a7fc8eaa3d592c260d50c7129e094ded
Gitweb: http://git.kernel.org/tip/b11e2e18a7fc8eaa3d592c260d50c7129e094ded
Author: Eric Biggers <ebiggers@google.com>
AuthorDate: Sun, 24 Sep 2017 12:59:06 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 26 Sep 2017 09:43:46 +0200
x86/fpu: Use validate_xstate_header() to validate the xstate_header in __fpu__restore_sig()
Tighten the checks in __fpu__restore_sig() and update comments.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers3@gmail.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
Link: http://lkml.kernel.org/r/20170924105913.9157-4-mingo@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/fpu/signal.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c
index 7fa3bdb..fb639e7 100644
--- a/arch/x86/kernel/fpu/signal.c
+++ b/arch/x86/kernel/fpu/signal.c
@@ -214,8 +214,11 @@ sanitize_restored_xstate(struct task_struct *tsk,
struct xstate_header *header = &xsave->header;
if (use_xsave()) {
- /* These bits must be zero. */
- memset(header->reserved, 0, 48);
+ /*
+ * Note: we don't need to zero the reserved bits in the
+ * xstate_header here because we either didn't copy them at all,
+ * or we checked earlier that they aren't set.
+ */
/*
* Init the state that is not present in the memory
@@ -224,7 +227,7 @@ sanitize_restored_xstate(struct task_struct *tsk,
if (fx_only)
header->xfeatures = XFEATURE_MASK_FPSSE;
else
- header->xfeatures &= (xfeatures_mask & xfeatures);
+ header->xfeatures &= xfeatures;
}
if (use_fxsr()) {
@@ -308,7 +311,7 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
/*
* For 32-bit frames with fxstate, copy the user state to the
* thread's fpu state, reconstruct fxstate from the fsave
- * header. Sanitize the copied state etc.
+ * header. Validate and sanitize the copied state.
*/
struct fpu *fpu = &tsk->thread.fpu;
struct user_i387_ia32_struct env;
@@ -329,9 +332,8 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
} else {
err = __copy_from_user(&fpu->state.xsave, buf_fx, state_size);
- /* xcomp_bv must be 0 when using uncompacted format */
- if (!err && state_size > offsetof(struct xregs_state, header) && fpu->state.xsave.header.xcomp_bv)
- err = -EINVAL;
+ if (!err && state_size > offsetof(struct xregs_state, header))
+ err = validate_xstate_header(&fpu->state.xsave.header);
}
if (err || __copy_from_user(&env, buf, sizeof(env))) {
next prev parent reply other threads:[~2017-09-26 8:44 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-24 10:59 [PATCH 00/10] x86/fpu: Split up "x86/fpu: Tighten validation of user-supplied xstate_header" Ingo Molnar
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-bot for Eric Biggers [this message]
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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