From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZpNGDFbGFdTDfX9BLfnf/l7jvkCLQr6erau0IXJ/w82gPqvyssK5bxgjeeSYeAFse/tEJWw ARC-Seal: i=1; a=rsa-sha256; t=1526282394; cv=none; d=google.com; s=arc-20160816; b=gdptvC1R8KhfJRP8f9W7qNjtGjfpCxpre7nlJ6GHInVQGFP5k1mFF1DcUkeEWceP/P CgC4EmxF/aCp1e5LZzWdc0SnUaj84Rkl+m3EqL5BNYNSOJ1rnbzNY7dz5QbyvVQmT/Yg qVkkzsNX/K18s+lJbaXP5qMq1c7n7HW/JOPnQUWoIzGemmpx7+a342q0bJ/RCZkGgxOY uZWhJuGMQhREsdE8n3aM4tceRRjy9CEtgEUSy5eibdj1Faf3VQ9ED8HPc6oLIfHxYiX1 wM6E8tjl74Z+hYSRMNvyV7E6bx9d+Ivk39uHf25SO6cssPz40RAUOI+hUvlB8DpyMD9r dFTw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:dkim-signature:arc-authentication-results; bh=CYSUTY3n79BkXQIU5fgnF17V6I8HyKMnIjucrd+0kig=; b=p5fQhrjhY4UM1sSh39MVrGUdUn3eiC5pSv3sk2wEjI1MwYzb/IjOw6/n+76R+lubwc LEUYPvulbhV47uE4Z1JGMuJSFwE+0+uyolwxCBJRzHgezcIU2CQMZwce+vLfehJuUpIN jsMKggW7vCV9sKA2LuMWZWsBoekvY9v6Bl/OrdqE2bbqGAvoJkGbwDr8kh4CFrjqvz3A rpWKfbDHeWIldT9WVA64LhV4OtUHs58FPdU6gt70sKSzdqo5ypMGSreQmfjSbxQyK25T RZNFOKctBnc6/O57UgpKr2jaWFIYvQ9c4oLfYslVXeQGTbEgmY8nlj70RI8d3/c0s7p+ X8MQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=QGTru99h; spf=pass (google.com: domain of srs0=ywzk=ib=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=ywzk=IB=linuxfoundation.org=gregkh@kernel.org Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=QGTru99h; spf=pass (google.com: domain of srs0=ywzk=ib=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=ywzk=IB=linuxfoundation.org=gregkh@kernel.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , "Peter Zijlstra (Intel)" , Alexander Shishkin , Arnaldo Carvalho de Melo , Jiri Olsa , Linus Torvalds , Stephane Eranian , Thomas Gleixner , Vince Weaver , Ingo Molnar Subject: [PATCH 4.16 71/72] perf/core: Fix possible Spectre-v1 indexing for ->aux_pages[] Date: Mon, 14 May 2018 08:49:28 +0200 Message-Id: <20180514064828.057552342@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180514064823.033169170@linuxfoundation.org> References: <20180514064823.033169170@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1600422462427122236?= X-GMAIL-MSGID: =?utf-8?q?1600423088113803226?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Peter Zijlstra commit 4411ec1d1993e8dbff2898390e3fed280d88e446 upstream. > kernel/events/ring_buffer.c:871 perf_mmap_to_page() warn: potential spectre issue 'rb->aux_pages' Userspace controls @pgoff through the fault address. Sanitize the array index before doing the array dereference. Reported-by: Dan Carpenter Signed-off-by: Peter Zijlstra (Intel) Cc: Cc: Alexander Shishkin Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- kernel/events/ring_buffer.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/kernel/events/ring_buffer.c +++ b/kernel/events/ring_buffer.c @@ -14,6 +14,7 @@ #include #include #include +#include #include "internal.h" @@ -867,8 +868,10 @@ perf_mmap_to_page(struct ring_buffer *rb return NULL; /* AUX space */ - if (pgoff >= rb->aux_pgoff) - return virt_to_page(rb->aux_pages[pgoff - rb->aux_pgoff]); + if (pgoff >= rb->aux_pgoff) { + int aux_pgoff = array_index_nospec(pgoff - rb->aux_pgoff, rb->aux_nr_pages); + return virt_to_page(rb->aux_pages[aux_pgoff]); + } } return __perf_mmap_to_page(rb, pgoff);