From patchwork Wed Sep 25 08:40:24 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?b?TElBTktVTiBZQU5HICjmnajov57lnaQp?= X-Patchwork-Id: 13811794 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 CC7ACC369AB for ; Wed, 25 Sep 2024 08:42:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: Content-Transfer-Encoding:MIME-Version: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:In-Reply-To:References:List-Owner; bh=r7DM1OmTlAwvtjukMDEk3ahsIfChXG9XjEPCHP7QFb8=; b=uo0/UnkCPQWTP8W4LwnDDeLoSd D3l1hTB3K8k1bgn1CBfRo8egKXatxaDHM2RuPH9LnTlySBS7CHD8asl2hmmjoT0uGrWOSk/B/Ih/s henzeGv8UBd9cE9oHez8kOeaLyhQMEX5MEDi/nCCWFe7jvmZoxLVBbkXuWiHZpDHPw8vWzDy42Kbz FlRoMpiqC/HGa+TjyKBGuIIwSo4fP5kAq1eWTJsJEA4ZXj2v+yB5jTcJmcCXkDQpSy8cXjopVlj57 T6fqoRJ4SDrlBPM1/RONN4IAYHOvxmVMnm+72/ng+IQq8AnF8YfFT78rxQHfeWVj8BspZVjTraP3t oFCbBWVA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1stNbe-00000004WhC-3kYt; Wed, 25 Sep 2024 08:42:42 +0000 Received: from mailgw01.mediatek.com ([216.200.240.184]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1stNaT-00000004WUp-2VO5; Wed, 25 Sep 2024 08:41:30 +0000 X-UUID: f11eb5647b1911efb3adad29d29602c1-20240925 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Type:Content-Transfer-Encoding:MIME-Version:Message-ID:Date:Subject:CC:To:From; bh=r7DM1OmTlAwvtjukMDEk3ahsIfChXG9XjEPCHP7QFb8=; b=r0iPZGwZFUbGpu8UKobqoePl7TIAvPreNeKEbZ1K+Xs24qHrWm3YvIeTKb5DtrowUsIrRSN2lkBt5yAPjK5zKNVVN4lzcDmn5hHZl7Yrz8/svdsGfp9eQ/j2YuMtk+QctE16SjX+IJdE0tRcWPcJk8BYx/NCpNgorKgI5fMT1HQ=; X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.41,REQID:f45f346a-cd2a-4505-a71e-05ff2972ad34,IP:0,U RL:0,TC:0,Content:-5,EDM:0,RT:0,SF:0,FILE:0,BULK:0,RULE:Release_Ham,ACTION :release,TS:-5 X-CID-META: VersionHash:6dc6a47,CLOUDID:147fbdd0-7921-4900-88a1-3aef019a55ce,B ulkID:nil,BulkQuantity:0,Recheck:0,SF:102,TC:nil,Content:0,EDM:-3,IP:nil,U RL:0,File:nil,RT:nil,Bulk:nil,QS:nil,BEC:nil,COL:0,OSI:0,OSA:0,AV:0,LES:1, SPR:NO,DKR:0,DKP:0,BRR:0,BRE:0,ARC:0 X-CID-BVR: 0,NGT X-CID-BAS: 0,NGT,0,_ X-CID-FACTOR: TF_CID_SPAM_SNR X-UUID: f11eb5647b1911efb3adad29d29602c1-20240925 Received: from mtkmbs09n2.mediatek.inc [(172.21.101.94)] by mailgw01.mediatek.com (envelope-from ) (musrelay.mediatek.com ESMTP with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 1746190837; Wed, 25 Sep 2024 01:41:22 -0700 Received: from mtkmbs13n2.mediatek.inc (172.21.101.108) by mtkmbs10n1.mediatek.inc (172.21.101.34) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.26; Wed, 25 Sep 2024 16:41:17 +0800 Received: from mszsdhlt06.gcn.mediatek.inc (10.16.6.206) by mtkmbs13n2.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.2.1118.26 via Frontend Transport; Wed, 25 Sep 2024 16:41:17 +0800 From: Liankun Yang To: , , , , , , , , , , , , , CC: , , , , Subject: [PATCH v1 1/1] drm/mediatek: Fix wrong check of nvmem_cell_read Date: Wed, 25 Sep 2024 16:40:24 +0800 Message-ID: <20240925084116.28848-1-liankun.yang@mediatek.com> X-Mailer: git-send-email 2.45.2 MIME-Version: 1.0 X-TM-AS-Product-Ver: SMEX-14.0.0.3152-9.1.1006-23728.005 X-TM-AS-Result: No-10--5.492400-8.000000 X-TMASE-MatchedRID: SuWkWSV/ibcryFHbNnBLG0KcYi5Qw/RVsEf8CpnIYtnfc2Xd6VJ+ynOQ FTxg7zBiief1bXK4Giqi5055Kxg7KbBAQLqGlKiv4pdq9sdj8LUFHCcDXik5Rpsoi2XrUn/Js98 n9dYnJNNQSFbL1bvQASAHAopEd76vrTCa7ZKhhkhBggx/bFjh7r0Dqq+NSXuwaGjbsK/Gvmg8gV 7uQwboPw== X-TM-AS-User-Approved-Sender: No X-TM-AS-User-Blocked-Sender: No X-TMASE-Result: 10--5.492400-8.000000 X-TMASE-Version: SMEX-14.0.0.3152-9.1.1006-23728.005 X-TM-SNTS-SMTP: 13CCA0BB40EB3E96C6F46EEAE16D8E08228DAD574439DD1B6B754A5BEAC8938E2000:8 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240925_014129_670596_C2AAE93E X-CRM114-Status: GOOD ( 10.90 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org If the len is 0, kernel crash will occur when performing operations. Add the len check conditions to prevent kernel crash. Fixes: f70ac097a2cf ("drm/mediatek: Add MT8195 Embedded DisplayPort driver") Signed-off-by: Liankun Yang --- drivers/gpu/drm/mediatek/mtk_dp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c index d8796a904eca..0cc75ba96b98 100644 --- a/drivers/gpu/drm/mediatek/mtk_dp.c +++ b/drivers/gpu/drm/mediatek/mtk_dp.c @@ -1082,7 +1082,7 @@ static void mtk_dp_get_calibration_data(struct mtk_dp *mtk_dp) buf = (u32 *)nvmem_cell_read(cell, &len); nvmem_cell_put(cell); - if (IS_ERR(buf) || ((len / sizeof(u32)) != 4)) { + if (IS_ERR(buf) || (len == 0) || ((len / sizeof(u32)) != 4)) { dev_warn(dev, "Failed to read nvmem_cell_read\n"); if (!IS_ERR(buf))