From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELsTUbggAdytWjHdW83l5itnA+axOJW9TQR+rJ6haDW89bRhcmmHPGZDbnwsG+UGUzRKCNQk ARC-Seal: i=1; a=rsa-sha256; t=1521483884; cv=none; d=google.com; s=arc-20160816; b=ik7HLrQ3FhsvsyrHH31VqyHwrxdLbwHpfCL3ZKqVeJq1Mk+ApiXQshlbDhxa2XzAlR JU4NfJ0XSVEko1IKWZDq7WoK0lcAOBC6EjDpaUXxvazm64RJ5OXIx41UY4Y5DaQdACIT KF5BzyeX5vEER4Kmaxm7f6PsJqP8vw3Oq+C/qigxi0rdgczEDhPcczuOWG/ejzJ5NaWs izTmAzhuOQOWE79lxcTHGI2EQt5PLfM2ZsVAroF0THlWuz9J+C+oFGPNhiKFiu2CDJ0N bTevjyX024wsO1i06yq/HPFUpb91KAbC1vsp/sGPcj+UI6fs4YSXA1ZXz04oCWf+5NRc z6JQ== 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:arc-authentication-results; bh=0v3HRY50vYU0PwM1UVl0Gad/3ow5H1AAghNmVno68jA=; b=iK7rRUM0kzINQjU/+dSeZC2MxUX8JMvUeNyXW8aHkp4DEnKN4Mn2JZIfH9FODAiHQn D0LBvk6HzxoyWGh99yK12rdeOOsPwRyjgSke1hHdmaFs+J7AbmP/CIX07ben+U5sq1ZM rs5iklnbq8YDWvk3sjMqZO5HYxij3tXLDf0byGH1NUeYxJCfBeGP9WnZs5+X2rP+3kyx jP1sMquJD0ZQLA0vz2nq6jDsOwqEAUHp4vquI9+nLx2QJx9eyL9eeMryCh+/cSeR+eun H4ricZiAuDy1HeCqXzUwQh8bL4zaWd5I8dW+emNxxsHZhGHOx/jSh80tzL6zWbZ1wWfx Y8VA== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andrey Ryabinin , Masami Hiramatsu , Ananth N Mavinakayanahalli , Anil S Keshavamurthy , Borislav Petkov , Brian Gerst , "David S . Miller" , Denys Vlasenko , "H. Peter Anvin" , Josh Poimboeuf , Linus Torvalds , Peter Zijlstra , Thomas Gleixner , Ye Xiaolong , Ingo Molnar , Sasha Levin Subject: [PATCH 4.9 153/241] kprobes/x86: Set kprobes pages read-only Date: Mon, 19 Mar 2018 19:06:58 +0100 Message-Id: <20180319180757.511132837@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180319180751.172155436@linuxfoundation.org> References: <20180319180751.172155436@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?1595390679028073105?= X-GMAIL-MSGID: =?utf-8?q?1595391485194248899?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Masami Hiramatsu [ Upstream commit d0381c81c2f782fa2131178d11e0cfb23d50d631 ] Set the pages which is used for kprobes' singlestep buffer and optprobe's trampoline instruction buffer to readonly. This can prevent unexpected (or unintended) instruction modification. This also passes rodata_test as below. Without this patch, rodata_test shows a warning: WARNING: CPU: 0 PID: 1 at arch/x86/mm/dump_pagetables.c:235 note_page+0x7a9/0xa20 x86/mm: Found insecure W+X mapping at address ffffffffa0000000/0xffffffffa0000000 With this fix, no W+X pages are found: x86/mm: Checked W+X mappings: passed, no W+X pages found. rodata_test: all tests were successful Reported-by: Andrey Ryabinin Signed-off-by: Masami Hiramatsu Cc: Ananth N Mavinakayanahalli Cc: Anil S Keshavamurthy Cc: Borislav Petkov Cc: Brian Gerst Cc: David S . Miller Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Ye Xiaolong Link: http://lkml.kernel.org/r/149076375592.22469.14174394514338612247.stgit@devbox Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/kprobes/core.c | 4 ++++ arch/x86/kernel/kprobes/opt.c | 3 +++ 2 files changed, 7 insertions(+) --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -409,6 +409,8 @@ static int arch_copy_kprobe(struct kprob { int ret; + set_memory_rw((unsigned long)p->ainsn.insn & PAGE_MASK, 1); + /* Copy an instruction with recovering if other optprobe modifies it.*/ ret = __copy_instruction(p->ainsn.insn, p->addr); if (!ret) @@ -423,6 +425,8 @@ static int arch_copy_kprobe(struct kprob else p->ainsn.boostable = -1; + set_memory_ro((unsigned long)p->ainsn.insn & PAGE_MASK, 1); + /* Check whether the instruction modifies Interrupt Flag or not */ p->ainsn.if_modifier = is_IF_modifier(p->ainsn.insn); --- a/arch/x86/kernel/kprobes/opt.c +++ b/arch/x86/kernel/kprobes/opt.c @@ -371,6 +371,7 @@ int arch_prepare_optimized_kprobe(struct } buf = (u8 *)op->optinsn.insn; + set_memory_rw((unsigned long)buf & PAGE_MASK, 1); /* Copy instructions into the out-of-line buffer */ ret = copy_optimized_instructions(buf + TMPL_END_IDX, op->kp.addr); @@ -393,6 +394,8 @@ int arch_prepare_optimized_kprobe(struct synthesize_reljump(buf + TMPL_END_IDX + op->optinsn.size, (u8 *)op->kp.addr + op->optinsn.size); + set_memory_ro((unsigned long)buf & PAGE_MASK, 1); + flush_icache_range((unsigned long) buf, (unsigned long) buf + TMPL_END_IDX + op->optinsn.size + RELATIVEJUMP_SIZE);