linux-kernel - [tip:x86/fpu] x86/fpu/xstate: Return NULL for disabled xstate component address

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <tip-5060b91513b866f774da15dfd82157864c4b1683@git.kernel.org>
Date:	Mon, 11 Jul 2016 09:13:22 -0700
From:	tip-bot for Yu-cheng Yu <tipbot@...or.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	yu-cheng.yu@...el.com, h.peter.anvin@...el.com,
	linux-kernel@...r.kernel.org, tglx@...utronix.de, hpa@...or.com,
	torvalds@...ux-foundation.org, peterz@...radead.org,
	fenghua.yu@...el.com, mingo@...nel.org, ravi.v.shankar@...el.com,
	dave.hansen@...el.com
Subject: [tip:x86/fpu] x86/fpu/xstate: Return NULL for disabled xstate
 component address

Commit-ID:  5060b91513b866f774da15dfd82157864c4b1683
Gitweb:     http://git.kernel.org/tip/5060b91513b866f774da15dfd82157864c4b1683
Author:     Yu-cheng Yu <yu-cheng.yu@...el.com>
AuthorDate: Mon, 11 Jul 2016 09:18:55 -0700
Committer:  Ingo Molnar <mingo@...nel.org>
CommitDate: Mon, 11 Jul 2016 16:44:00 +0200

x86/fpu/xstate: Return NULL for disabled xstate component address

It is an error to request a disabled XSAVE/XSAVES component address.
For that case, make __raw_xsave_addr() return a NULL and issue a
warning.

Signed-off-by: Yu-cheng Yu <yu-cheng.yu@...el.com>
Signed-off-by: Fenghua Yu <fenghua.yu@...el.com>
Reviewed-by: Dave Hansen <dave.hansen@...el.com>
Cc: H. Peter Anvin <h.peter.anvin@...el.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Ravi V Shankar <ravi.v.shankar@...el.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Link: http://lkml.kernel.org/r/1468253937-40008-3-git-send-email-fenghua.yu@intel.com
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 arch/x86/kernel/fpu/xstate.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index f8d1aff..4fb8dd7 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -760,6 +760,11 @@ void *__raw_xsave_addr(struct xregs_state *xsave, int xstate_feature_mask)
 {
 	int feature_nr = fls64(xstate_feature_mask) - 1;
 
+	if (!xfeature_enabled(feature_nr)) {
+		WARN_ON_FPU(1);
+		return NULL;
+	}
+
 	return (void *)xsave + xstate_comp_offsets[feature_nr];
 }
 /*