From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7568BC00144 for ; Mon, 1 Aug 2022 19:05:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=3ahp/96PufjeoyHGtQmA3sBSRyGxtwmlIhvJU8N2R+0=; b=njgpEnJEkgpjwV u2U4Dt+9ricdQOUWXelpVmzglrpmB379OVfZCQe4wiChgyuQNR7q7bCQ+GD7dPsHmjEVDUuiD8ioB SF00cfY9aNj0zVSCegxiQkjqP4sQqc2Pe0EsC6X3tMtxxxiniuKqUjqn5sJ481Yi+PnM1q+RvG0qb wCLD1UgKDYTEbQ48Yw+7hckzNnxX2HclxaKPvlp3EiELNRkG9MXC5+e13IL76BzrbSAGI721eu9hk N6izBnkKSBIB9rddUoI5T/1sCEk87AKfFHW9lEOUaoSJq1jKtgoUNzbnaaT3Ry9T2DwONwLuNI6lA atdjHo+dGPf1gtGBXOMA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oIahv-009bP6-SV; Mon, 01 Aug 2022 19:04:03 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oIahr-009bLi-GT for linux-arm-kernel@lists.infradead.org; Mon, 01 Aug 2022 19:04:00 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 13F1460D33; Mon, 1 Aug 2022 19:03:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B3AAFC433D6; Mon, 1 Aug 2022 19:03:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1659380638; bh=eJ/v+3pMrhsCBUeLH+bTGVxMH9aUHe0sDu0CXot8KL8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=upSCegc/wAySxiSPhftxrGhRbh4zTctIzqZiBi6gZ7XhmVlCIPik93MjIQTJCMkIe VSFya0Ci5DdltQ/OwN41sC5tbwr+zi/nk/L3xFM9i4fcHgSFBMQwXqhuWxLSthvnGj r/rRE3Zj1HA7AxpkR9Oj4QEXqz9PhkDZ+Wzf62Zb9bM+dLf/1UFDHlM+UfM4l/NDYw 5Oe+E3ler3ywEx9AJPnTARv3ToJc7kZi34yJWuud091lxCPmcoSMfrTLF93p8BNYRu 70qoVyFp8qLt+B2TGt1GLfyIIxzkOYhKUdYxcskWhsqo5uCHJmQz9nOtuI8WHfMZh6 67ihRUlDdn4kA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Russell King (Oracle)" , Guenter Roeck , Sasha Levin , linux@armlinux.org.uk, linux-arm-kernel@lists.infradead.org Subject: [PATCH AUTOSEL 4.14 3/3] ARM: findbit: fix overflowing offset Date: Mon, 1 Aug 2022 15:03:43 -0400 Message-Id: <20220801190344.3820044-3-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220801190344.3820044-1-sashal@kernel.org> References: <20220801190344.3820044-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220801_120359_591718_978034CF X-CRM114-Status: GOOD ( 13.77 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: "Russell King (Oracle)" [ Upstream commit ec85bd369fd2bfaed6f45dd678706429d4f75b48 ] When offset is larger than the size of the bit array, we should not attempt to access the array as we can perform an access beyond the end of the array. Fix this by changing the pre-condition. Using "cmp r2, r1; bhs ..." covers us for the size == 0 case, since this will always take the branch when r1 is zero, irrespective of the value of r2. This means we can fix this bug without adding any additional code! Tested-by: Guenter Roeck Signed-off-by: Russell King (Oracle) Signed-off-by: Sasha Levin --- arch/arm/lib/findbit.S | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/arch/arm/lib/findbit.S b/arch/arm/lib/findbit.S index 7848780e8834..20fef6c41f6f 100644 --- a/arch/arm/lib/findbit.S +++ b/arch/arm/lib/findbit.S @@ -43,8 +43,8 @@ ENDPROC(_find_first_zero_bit_le) * Prototype: int find_next_zero_bit(void *addr, unsigned int maxbit, int offset) */ ENTRY(_find_next_zero_bit_le) - teq r1, #0 - beq 3b + cmp r2, r1 + bhs 3b ands ip, r2, #7 beq 1b @ If new byte, goto old routine ARM( ldrb r3, [r0, r2, lsr #3] ) @@ -84,8 +84,8 @@ ENDPROC(_find_first_bit_le) * Prototype: int find_next_zero_bit(void *addr, unsigned int maxbit, int offset) */ ENTRY(_find_next_bit_le) - teq r1, #0 - beq 3b + cmp r2, r1 + bhs 3b ands ip, r2, #7 beq 1b @ If new byte, goto old routine ARM( ldrb r3, [r0, r2, lsr #3] ) @@ -118,8 +118,8 @@ ENTRY(_find_first_zero_bit_be) ENDPROC(_find_first_zero_bit_be) ENTRY(_find_next_zero_bit_be) - teq r1, #0 - beq 3b + cmp r2, r1 + bhs 3b ands ip, r2, #7 beq 1b @ If new byte, goto old routine eor r3, r2, #0x18 @ big endian byte ordering @@ -152,8 +152,8 @@ ENTRY(_find_first_bit_be) ENDPROC(_find_first_bit_be) ENTRY(_find_next_bit_be) - teq r1, #0 - beq 3b + cmp r2, r1 + bhs 3b ands ip, r2, #7 beq 1b @ If new byte, goto old routine eor r3, r2, #0x18 @ big endian byte ordering -- 2.35.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 67959C00144 for ; Mon, 1 Aug 2022 19:07:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234025AbiHATHY (ORCPT ); Mon, 1 Aug 2022 15:07:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53074 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234706AbiHATGc (ORCPT ); Mon, 1 Aug 2022 15:06:32 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3BCE0357CC; Mon, 1 Aug 2022 12:04:00 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 13F3961213; Mon, 1 Aug 2022 19:03:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B3AAFC433D6; Mon, 1 Aug 2022 19:03:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1659380638; bh=eJ/v+3pMrhsCBUeLH+bTGVxMH9aUHe0sDu0CXot8KL8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=upSCegc/wAySxiSPhftxrGhRbh4zTctIzqZiBi6gZ7XhmVlCIPik93MjIQTJCMkIe VSFya0Ci5DdltQ/OwN41sC5tbwr+zi/nk/L3xFM9i4fcHgSFBMQwXqhuWxLSthvnGj r/rRE3Zj1HA7AxpkR9Oj4QEXqz9PhkDZ+Wzf62Zb9bM+dLf/1UFDHlM+UfM4l/NDYw 5Oe+E3ler3ywEx9AJPnTARv3ToJc7kZi34yJWuud091lxCPmcoSMfrTLF93p8BNYRu 70qoVyFp8qLt+B2TGt1GLfyIIxzkOYhKUdYxcskWhsqo5uCHJmQz9nOtuI8WHfMZh6 67ihRUlDdn4kA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Russell King (Oracle)" , Guenter Roeck , Sasha Levin , linux@armlinux.org.uk, linux-arm-kernel@lists.infradead.org Subject: [PATCH AUTOSEL 4.14 3/3] ARM: findbit: fix overflowing offset Date: Mon, 1 Aug 2022 15:03:43 -0400 Message-Id: <20220801190344.3820044-3-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220801190344.3820044-1-sashal@kernel.org> References: <20220801190344.3820044-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Russell King (Oracle)" [ Upstream commit ec85bd369fd2bfaed6f45dd678706429d4f75b48 ] When offset is larger than the size of the bit array, we should not attempt to access the array as we can perform an access beyond the end of the array. Fix this by changing the pre-condition. Using "cmp r2, r1; bhs ..." covers us for the size == 0 case, since this will always take the branch when r1 is zero, irrespective of the value of r2. This means we can fix this bug without adding any additional code! Tested-by: Guenter Roeck Signed-off-by: Russell King (Oracle) Signed-off-by: Sasha Levin --- arch/arm/lib/findbit.S | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/arch/arm/lib/findbit.S b/arch/arm/lib/findbit.S index 7848780e8834..20fef6c41f6f 100644 --- a/arch/arm/lib/findbit.S +++ b/arch/arm/lib/findbit.S @@ -43,8 +43,8 @@ ENDPROC(_find_first_zero_bit_le) * Prototype: int find_next_zero_bit(void *addr, unsigned int maxbit, int offset) */ ENTRY(_find_next_zero_bit_le) - teq r1, #0 - beq 3b + cmp r2, r1 + bhs 3b ands ip, r2, #7 beq 1b @ If new byte, goto old routine ARM( ldrb r3, [r0, r2, lsr #3] ) @@ -84,8 +84,8 @@ ENDPROC(_find_first_bit_le) * Prototype: int find_next_zero_bit(void *addr, unsigned int maxbit, int offset) */ ENTRY(_find_next_bit_le) - teq r1, #0 - beq 3b + cmp r2, r1 + bhs 3b ands ip, r2, #7 beq 1b @ If new byte, goto old routine ARM( ldrb r3, [r0, r2, lsr #3] ) @@ -118,8 +118,8 @@ ENTRY(_find_first_zero_bit_be) ENDPROC(_find_first_zero_bit_be) ENTRY(_find_next_zero_bit_be) - teq r1, #0 - beq 3b + cmp r2, r1 + bhs 3b ands ip, r2, #7 beq 1b @ If new byte, goto old routine eor r3, r2, #0x18 @ big endian byte ordering @@ -152,8 +152,8 @@ ENTRY(_find_first_bit_be) ENDPROC(_find_first_bit_be) ENTRY(_find_next_bit_be) - teq r1, #0 - beq 3b + cmp r2, r1 + bhs 3b ands ip, r2, #7 beq 1b @ If new byte, goto old routine eor r3, r2, #0x18 @ big endian byte ordering -- 2.35.1