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[209.132.180.67]) by mx.google.com with ESMTP id v63si6543334pgd.111.2019.08.01.01.20.59; Thu, 01 Aug 2019 01:20:59 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=rI4dN04P; spf=pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730656AbfHAIU7 (ORCPT + 14 others); Thu, 1 Aug 2019 04:20:59 -0400 Received: from mail-pf1-f196.google.com ([209.85.210.196]:39185 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727171AbfHAIU7 (ORCPT ); Thu, 1 Aug 2019 04:20:59 -0400 Received: by mail-pf1-f196.google.com with SMTP id f17so29614381pfn.6 for ; Thu, 01 Aug 2019 01:20:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=83Q5DLuQYSva53SfstGNLwQ+WusgochK7tEX54DLnZk=; b=rI4dN04PCrS8oEfhhu1FimQvBZ8VBzO1CvaxoGD0C6HzZI6J1xXoWDHX2NESLp/Gu7 7/G8HfBb07K3/rgxPknRTOvB3aLF023teB3bfyIRyAR+J8H4K9LaMWtxu70jFDgK74EX d5yKiB/4rRbxtd1QdEtqb0PY9C3bjQM4DYhFHaErCxKRZDpe+KlfB4THeuDtUHgMKne0 tAcVx3VWyyaYMIEQmAFWy51kwzUYHaZxrC4iPgcfUez/yyp4OS9lBBifrZ0sEM4m2uBe HN9oapm4F9z9UV++zkll/G0/DnOcFJFTYG1xzjUUiBgS5qLQw/8M46c9Qq8EW4MJ4sTk pdDg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=83Q5DLuQYSva53SfstGNLwQ+WusgochK7tEX54DLnZk=; b=rTt8gxpf4edvAhgXritg6cCEyyYCghZ9a2rjygmIDWs093v1FHvTgLQ6Wu8kwfZeOF ynU9yJ7bCLCOneKTNh4ReDkMKLejcjBYH++INbgUqfRTwLlZTkLAExU5Q6C50nha56C4 3sft9i5teS18i2kdmvOINOvbUaEoqEwAiyyGgk0gU5aPBWULxySgIg/PEqa4dg0zV2LJ dpGeclXzTSns7omKQRKcyRnAmO0EfSA0POKNzx4cOKAmwWXUInXiRKxYQ5Dlfb/KREO/ Gyuzj6l+mc4mJe6S4dmLuNznEre6KTPiGgVs6NxH8jK1tIPgaBRbT6MGPVyPVLpagRZX vKjw== X-Gm-Message-State: APjAAAWK9Le13+BbAMUJLayscaSA7MVX+n/a8YerXaZdvGipeCElJrNP +Dt8rLhIYRCl6CNBlREfwO6duivIvnk= X-Received: by 2002:a62:14c4:: with SMTP id 187mr50562879pfu.241.1564647658137; Thu, 01 Aug 2019 01:20:58 -0700 (PDT) Received: from localhost ([122.172.28.117]) by smtp.gmail.com with ESMTPSA id j1sm95276210pgl.12.2019.08.01.01.20.57 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 01 Aug 2019 01:20:57 -0700 (PDT) From: Viresh Kumar To: stable@vger.kernel.org Cc: Viresh Kumar , Julien Thierry , linux-arm-kernel@lists.infradead.org, Catalin Marinas , Marc Zyngier , Mark Rutland , Will Deacon , Russell King , Vincent Guittot , mark.brown@arm.com, guohanjun@huawei.com Subject: [PATCH ARM32 v4.4 V2 32/47] ARM: 8794/1: uaccess: Prevent speculative use of the current addr_limit Date: Thu, 1 Aug 2019 13:46:16 +0530 Message-Id: <74663c62c712201d35d012eba43ad611b6c5a3fe.1564646727.git.viresh.kumar@linaro.org> X-Mailer: git-send-email 2.21.0.rc0.269.g1a574e7a288b In-Reply-To: References: MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Julien Thierry Commit 621afc677465db231662ed126ae1f355bf8eac47 upstream. A mispredicted conditional call to set_fs could result in the wrong addr_limit being forwarded under speculation to a subsequent access_ok check, potentially forming part of a spectre-v1 attack using uaccess routines. This patch prevents this forwarding from taking place, but putting heavy barriers in set_fs after writing the addr_limit. Porting commit c2f0ad4fc089cff8 ("arm64: uaccess: Prevent speculative use of the current addr_limit"). Signed-off-by: Julien Thierry Signed-off-by: Russell King Signed-off-by: Viresh Kumar --- arch/arm/include/asm/uaccess.h | 8 ++++++++ 1 file changed, 8 insertions(+) -- 2.21.0.rc0.269.g1a574e7a288b diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h index ecd159b45f12..a782201a2629 100644 --- a/arch/arm/include/asm/uaccess.h +++ b/arch/arm/include/asm/uaccess.h @@ -99,6 +99,14 @@ extern int __put_user_bad(void); static inline void set_fs(mm_segment_t fs) { current_thread_info()->addr_limit = fs; + + /* + * Prevent a mispredicted conditional call to set_fs from forwarding + * the wrong address limit to access_ok under speculation. + */ + dsb(nsh); + isb(); + modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER); }