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 8A938C00144 for ; Mon, 1 Aug 2022 19:04:53 +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=o9hcIgKHXT2fdu YzOMhOdbEutgAz/1Iz2kY4xSvxrKOlHG1BQyBZs9o/TNG3YOO4mtrF9OxdIR8FPardrQTMinR4gS9 LKXXR+EeCGyztluPNYMLm8yMUPw+BNyjYa1O1z0gcVVzSFhzM1GLQRTw/k5bgACBxhoMA4ee9X8LX S/YFYh19pg69wfs1cwnUzHpYD9n36YCJnTlupuOB1bZWEWpdcvZO8gPa+//0MK6gC98oFX6weEr9o q5O5ysHA6GXKVji2SqjbbbqD7lqoIy4Iwr4UFE0MhnM6VW0sZ7btcC0oI/py2Y+AAGLry+nFSpI+W Wa+zZwHMCK7/0oaoG2kA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oIahg-009bDs-FG; Mon, 01 Aug 2022 19:03:48 +0000 Received: from ams.source.kernel.org ([145.40.68.75]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oIahc-009bAh-Pe for linux-arm-kernel@lists.infradead.org; Mon, 01 Aug 2022 19:03:46 +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 ams.source.kernel.org (Postfix) with ESMTPS id 7545CB81616; Mon, 1 Aug 2022 19:03:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 56EFCC43470; Mon, 1 Aug 2022 19:03:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1659380623; bh=eJ/v+3pMrhsCBUeLH+bTGVxMH9aUHe0sDu0CXot8KL8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Qr36dVBfODTc1PgL8z6zomjMII1lfiGO0I0tT9etheAiLKQ20rZ0czz8p/myAdwJk 8rd3+iLu3b3yMtvahDFbspzzfA0j7qSqnkF4GsFlYJ88u/BHOTafE+gVOltYAk3fcu yTCPPOK5EygNtk56K+coJfkmGj9TcQVQQhuhHtuwIT7dlUCru2ZM9mrgHu/dX+fO44 C02Pw2mpz702OvcR0npkTVBX44MYDs9EYnYJyHQvHn7ulLMSB18+Kh7S1ZXD77nU3g 69R1Slttu55XZRNiAHXHWRuPoQPUCdeZlf/jMmqsLTsa2tJGv09odv6emTyLwurkkd +pTRH2CyktCSw== 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 4.19 4/4] ARM: findbit: fix overflowing offset Date: Mon, 1 Aug 2022 15:03:31 -0400 Message-Id: <20220801190331.3819791-4-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220801190331.3819791-1-sashal@kernel.org> References: <20220801190331.3819791-1-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_120345_064736_68F67B29 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 F1F22C00144 for ; Mon, 1 Aug 2022 19:07:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234863AbiHATG7 (ORCPT ); Mon, 1 Aug 2022 15:06:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52276 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234756AbiHATFr (ORCPT ); Mon, 1 Aug 2022 15:05:47 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CC7D643313; Mon, 1 Aug 2022 12:03:44 -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 ams.source.kernel.org (Postfix) with ESMTPS id 6D3C6B81615; Mon, 1 Aug 2022 19:03:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 56EFCC43470; Mon, 1 Aug 2022 19:03:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1659380623; bh=eJ/v+3pMrhsCBUeLH+bTGVxMH9aUHe0sDu0CXot8KL8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Qr36dVBfODTc1PgL8z6zomjMII1lfiGO0I0tT9etheAiLKQ20rZ0czz8p/myAdwJk 8rd3+iLu3b3yMtvahDFbspzzfA0j7qSqnkF4GsFlYJ88u/BHOTafE+gVOltYAk3fcu yTCPPOK5EygNtk56K+coJfkmGj9TcQVQQhuhHtuwIT7dlUCru2ZM9mrgHu/dX+fO44 C02Pw2mpz702OvcR0npkTVBX44MYDs9EYnYJyHQvHn7ulLMSB18+Kh7S1ZXD77nU3g 69R1Slttu55XZRNiAHXHWRuPoQPUCdeZlf/jMmqsLTsa2tJGv09odv6emTyLwurkkd +pTRH2CyktCSw== 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 4.19 4/4] ARM: findbit: fix overflowing offset Date: Mon, 1 Aug 2022 15:03:31 -0400 Message-Id: <20220801190331.3819791-4-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220801190331.3819791-1-sashal@kernel.org> References: <20220801190331.3819791-1-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