From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZpn6IsVhGzHPbhVtvOcYVqLfV9LNxyxmqOetGOeOmTv+14Cq3pNGmcPf9LafDlQv0O+0EtG ARC-Seal: i=1; a=rsa-sha256; t=1526282287; cv=none; d=google.com; s=arc-20160816; b=OgKl/ZBPE8+O0oUcV5n8t007LWvIDmT+vFxKX7plo6L9d4R4vqFJi9YIhCBx95O099 yrNMbOCAXoBJHiom1z4i8cObxQPlV5LuGPJ5U9uoKFaHdmQIUFAUaFQh08LA7c18qp2i 4oG7+lpPVvo65uXYvD2jpIkMOF93vjrbRBKuIURjqi/bLhqGxMSLOThSyc+MrLjlB1lZ elCD5t+z4DfcPf57LlvcffHclu5AJdk/WWbLlktEM8kZ2AlMEoZ/eZVeB2fcIffZGtbb WKFY0r67kGMV3KxoblTvPE3lbto8xtepWNnn2P2+X6MXJiUA2mmM2ixCdVWwyXn6wLny yuJg== 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=MdAv0mnqumyLCDxX+8jQ8ym8dAIR2YYNzkkUN/y2hSo=; b=U0uKQl3EQ498IGFR7crfyYbiyYAeYTse6Ard2Erd7SRk4kaZN6bQrmEMH9FWN9YzXS pmH0DYQAQ7htdS2X43kfkMH1rSvJEvl4mEn7bjfQZ0iUeSxUET1PuVY3HXHPGQJ3GwG0 CDmehqrRQhlFlyAV6XBnlznzYr+CegOx/3+QTl8Q2VTSuzI1TgnGmKvuQckwOovNfIGH YDd/W/M/6iZBpx0rlPa+gi0cz1WK3a91567DhsS3sda67pk06a3oajcORIeGu3zpK9R7 5x3VEKPDvgj1t+4jI425/pY0F4AL7sa7Xltl0K1pEeLiqG8n++SN8W9WAKvTlqGPOR+v beeg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=ZIK3DWa5; 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=ZIK3DWa5; 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 4.14 59/62] perf/core: Fix possible Spectre-v1 indexing for ->aux_pages[] Date: Mon, 14 May 2018 08:49:15 +0200 Message-Id: <20180514064819.749587801@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180514064816.436958006@linuxfoundation.org> References: <20180514064816.436958006@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?1600422976493190440?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.14-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" @@ -863,8 +864,10 @@ 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);