From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZpXzdAI0CsWo3p0IM/zh6+a/RbU4fjAojlxfdshO490k4SndFqiZCRFCALGY61nLg1BNpeA ARC-Seal: i=1; a=rsa-sha256; t=1526937298; cv=none; d=google.com; s=arc-20160816; b=05QFzJwfVJN03yO01D9Z3u0Pvjb/ETfgRSr++sgJFx/Ogmzd1Xd6Pr7FjCOxwsRKLT 84BAcHxEAkiXM//tNc3XdK6cBXEK9TNGmH8c8ORyf/6bC4VFG6BpFjuzBXZvzld9KEKz sOat3gPqyQ6Haz7HyRuDpiLuAdgRsiiQQv9ybBQSWA8BdyVSVx/wA+NzPJQm+FVencF0 ektXffHzwzquMK/GaCC5La8hBlq1m1JQF1ohVyP33ZrFn4p+ILlIpyYAdnampVWRX84V csqVT7WEfE7nbWOpSy3n5OsDjtHdPaaZrh3mY0uvc/TfyWN6/3xIAHz7uu9D7IoQilAZ h/3w== 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=H7c/bvkb90lc5pZJAM0pgn+pQFtXkYubVTGg0OJ5hL8=; b=rbB5N4hA8x1BCeJFKRLYZrpwnbjwEEqLRBOnfBDNyYEt63vvpEuzrHDxkVBX30RAvd YpZ5RI/V/W/EAMm1hxVChZTZmawiNQ3XtpW9ObaUjaUrE8xl8AXzcly5bYoJjo3NfmGk xrqmBgfboxdCaGIRf7nNuXvKwWygIIdjpeZ9lHxyo1oXEZoVmCzLSDVpB3LKz7MeXSZb 8OFTldIMFqBQalC876hSxCYt6jSdwy9RTuST+b4BcQMLVmNukr5rdy0UvyZoubn0fOOO kS4WHrMEfUATDu/RtPcdt2SDI7JWwkpgcovkbwFV6WyDsrqC1zBDdyGDL80GJUiluHAm vPDA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=FSY9es0U; spf=pass (google.com: domain of srs0=nia/=ii=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=nia/=II=linuxfoundation.org=gregkh@kernel.org Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=FSY9es0U; spf=pass (google.com: domain of srs0=nia/=ii=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=nia/=II=linuxfoundation.org=gregkh@kernel.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Masami Hiramatsu , Russell King Subject: [PATCH 4.9 31/87] ARM: 8772/1: kprobes: Prohibit kprobes on get_user functions Date: Mon, 21 May 2018 23:11:07 +0200 Message-Id: <20180521210423.284827927@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180521210420.222671977@linuxfoundation.org> References: <20180521210420.222671977@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?1601109804932649139?= X-GMAIL-MSGID: =?utf-8?q?1601109804932649139?= 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 commit 0d73c3f8e7f6ee2aab1bb350f60c180f5ae21a2c upstream. Since do_undefinstr() uses get_user to get the undefined instruction, it can be called before kprobes processes recursive check. This can cause an infinit recursive exception. Prohibit probing on get_user functions. Fixes: 24ba613c9d6c ("ARM kprobes: core code") Signed-off-by: Masami Hiramatsu Cc: stable@vger.kernel.org Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman --- arch/arm/include/asm/assembler.h | 10 ++++++++++ arch/arm/lib/getuser.S | 10 ++++++++++ 2 files changed, 20 insertions(+) --- a/arch/arm/include/asm/assembler.h +++ b/arch/arm/include/asm/assembler.h @@ -534,4 +534,14 @@ THUMB( orr \reg , \reg , #PSR_T_BIT ) #endif .endm +#ifdef CONFIG_KPROBES +#define _ASM_NOKPROBE(entry) \ + .pushsection "_kprobe_blacklist", "aw" ; \ + .balign 4 ; \ + .long entry; \ + .popsection +#else +#define _ASM_NOKPROBE(entry) +#endif + #endif /* __ASM_ASSEMBLER_H__ */ --- a/arch/arm/lib/getuser.S +++ b/arch/arm/lib/getuser.S @@ -38,6 +38,7 @@ ENTRY(__get_user_1) mov r0, #0 ret lr ENDPROC(__get_user_1) +_ASM_NOKPROBE(__get_user_1) ENTRY(__get_user_2) check_uaccess r0, 2, r1, r2, __get_user_bad @@ -58,6 +59,7 @@ rb .req r0 mov r0, #0 ret lr ENDPROC(__get_user_2) +_ASM_NOKPROBE(__get_user_2) ENTRY(__get_user_4) check_uaccess r0, 4, r1, r2, __get_user_bad @@ -65,6 +67,7 @@ ENTRY(__get_user_4) mov r0, #0 ret lr ENDPROC(__get_user_4) +_ASM_NOKPROBE(__get_user_4) ENTRY(__get_user_8) check_uaccess r0, 8, r1, r2, __get_user_bad8 @@ -78,6 +81,7 @@ ENTRY(__get_user_8) mov r0, #0 ret lr ENDPROC(__get_user_8) +_ASM_NOKPROBE(__get_user_8) #ifdef __ARMEB__ ENTRY(__get_user_32t_8) @@ -91,6 +95,7 @@ ENTRY(__get_user_32t_8) mov r0, #0 ret lr ENDPROC(__get_user_32t_8) +_ASM_NOKPROBE(__get_user_32t_8) ENTRY(__get_user_64t_1) check_uaccess r0, 1, r1, r2, __get_user_bad8 @@ -98,6 +103,7 @@ ENTRY(__get_user_64t_1) mov r0, #0 ret lr ENDPROC(__get_user_64t_1) +_ASM_NOKPROBE(__get_user_64t_1) ENTRY(__get_user_64t_2) check_uaccess r0, 2, r1, r2, __get_user_bad8 @@ -114,6 +120,7 @@ rb .req r0 mov r0, #0 ret lr ENDPROC(__get_user_64t_2) +_ASM_NOKPROBE(__get_user_64t_2) ENTRY(__get_user_64t_4) check_uaccess r0, 4, r1, r2, __get_user_bad8 @@ -121,6 +128,7 @@ ENTRY(__get_user_64t_4) mov r0, #0 ret lr ENDPROC(__get_user_64t_4) +_ASM_NOKPROBE(__get_user_64t_4) #endif __get_user_bad8: @@ -131,6 +139,8 @@ __get_user_bad: ret lr ENDPROC(__get_user_bad) ENDPROC(__get_user_bad8) +_ASM_NOKPROBE(__get_user_bad) +_ASM_NOKPROBE(__get_user_bad8) .pushsection __ex_table, "a" .long 1b, __get_user_bad