From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZojDZ4UNKALB/yaxgQMRZHK4tYXinLABd48Rh3ilJ21w8ex7MxSIdi2EJUKWQN6uQnahVdj ARC-Seal: i=1; a=rsa-sha256; t=1526281797; cv=none; d=google.com; s=arc-20160816; b=yU8+7/bot8qZZGbZcZvtRIx5OrI886xZJ4hMo212LJgdFuILyEoll9j13m+K6v1IOj gDgJ05oFoNJ6yknPm0lFqefZRHaN4DWNy9y0NdSnIy7SeKdPoSjHwWlCL82k1NZ2a4zh IfaScWaDmbolkZGWbNA8wuVgS3zM6OZpWj+o2y6MAPXTC9WXFHLq31sr5cUhnlrXSM+P a7QUlUSGDjflbmw6/9M30Ng9FfRy7StPoWJycgQIyqRdFy2ciqYTTDjXjShGeeGMVlqv pxSxTnk7Bo6TlnaNfmLKy8biLq/n09wJs3zAuKAzaPEJW1AzXcF62YTPU7ZMsFuacM2P XR6w== 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=iyHwu3KgxB0jijuOQJQOYm6ksMbKdgQhPuVD0/JZKAg=; b=dE5S/NwMrVUv2XdJtnQ6qsZvhmWgbPNp+h92Y74J5rA2ubuyIi6YSgeVcSp54dSyLD 3DpNial+1Ob6kivp4G+ogVAFOQpY/FdT1wZPS8pNlfk4m6RMpKWWSdUFbqrCooOaaIh9 CYDte/Vrs1LqCFlmUqVG+FkhQfrSo0L35ySryLAy7kgeLHKepSfpG5HBmN64ntKiM4Oj wUWo345Gt6otYjofTvaDW3EDxJ9bbWGhtRCVKkJo+ZaPCQEGxPpqo3hgbkwyb71MYeXN 43rwHTtK6cvdwzUssi4hMigsVFU1l5VFZX2jG3CU6inUcXU6EvoZM9lbUdyuKrEafZOY yacQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=vLy3q+Sw; 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=vLy3q+Sw; 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 4.4 55/56] perf/core: Fix possible Spectre-v1 indexing for ->aux_pages[] Date: Mon, 14 May 2018 08:49:00 +0200 Message-Id: <20180514064759.985903547@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180514064754.853201981@linuxfoundation.org> References: <20180514064754.853201981@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?1600422462427122236?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.4-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" @@ -779,8 +780,10 @@ 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);