From patchwork Mon Dec 23 02:32:27 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guoqing Jiang X-Patchwork-Id: 13918613 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 CB21DE7718D for ; Mon, 23 Dec 2024 08:56:15 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B2EAB10E113; Mon, 23 Dec 2024 08:56:14 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=canonical.com header.i=@canonical.com header.b="VjFpcNmb"; dkim-atps=neutral Received: from smtp-relay-canonical-1.canonical.com (smtp-relay-canonical-1.canonical.com [185.125.188.121]) by gabe.freedesktop.org (Postfix) with ESMTPS id D2DF610E00E for ; Mon, 23 Dec 2024 02:32:40 +0000 (UTC) Received: from laptop.lan (unknown [123.123.43.248]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp-relay-canonical-1.canonical.com (Postfix) with ESMTPSA id 500BD4093D; Mon, 23 Dec 2024 02:32:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=canonical.com; s=20210705; t=1734921158; bh=5qnEfk34JXjmwcW6H1RfNrw1EbvlMd5bPIiUMHsYMUQ=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=VjFpcNmbP2cIiN2fMpSY7tpsMOnVXphLMOJjElWhkr4B+yUP1I8/mGqO8oTegomr9 OHwPVlWItAbBKYvuyGRt7xebumRpGxvt8TtjP0TZ3cXFw8K9S807u810DC6IiRKYfE xnRImfEGjJiDSq2smJG2owcldvQklL+x6qgQ9TDUTsiE9YGZE2TVtJZox3cgtgkhgD qoUekAoe1weTgjp0uBaBiJnYR1mTtN92PB3kGI46eFogjRjZCums6wgItNJnujj/zi 3Wrtvy9P4gqw1CDRaPcTun5pLJQl9hPzzeLWfDjJODEi1qZeQAd8E8cUK3PWyb8YiU G5m8Dy8MTo2/Q== From: Guoqing Jiang To: chunkuang.hu@kernel.org, p.zabel@pengutronix.de, airlied@gmail.com, simona@ffwll.ch, matthias.bgg@gmail.com, angelogioacchino.delregno@collabora.com, nancy.lin@mediatek.com Cc: dri-devel@lists.freedesktop.org, linux-mediatek@lists.infradead.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH V2] drm/mediatek: Set private->all_drm_private[i]->drm to NULL if mtk_drm_bind returns err Date: Mon, 23 Dec 2024 10:32:27 +0800 Message-Id: <20241223023227.1258112-1-guoqing.jiang@canonical.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-Mailman-Approved-At: Mon, 23 Dec 2024 08:56:13 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" The pointer need to be set to NULL, otherwise KASAN complains about use-after-free. Because in mtk_drm_bind, all private's drm are set as follows. private->all_drm_private[i]->drm = drm; And drm will be released by drm_dev_put in case mtk_drm_kms_init returns failure. However, the shutdown path still accesses the previous allocated memory in drm_atomic_helper_shutdown. [ 84.874820] watchdog: watchdog0: watchdog did not stop! [ 86.512054] ================================================================== [ 86.513162] BUG: KASAN: use-after-free in drm_atomic_helper_shutdown+0x33c/0x378 [ 86.514258] Read of size 8 at addr ffff0000d46fc068 by task shutdown/1 [ 86.515213] [ 86.515455] CPU: 1 UID: 0 PID: 1 Comm: shutdown Not tainted 6.13.0-rc1-mtk+gfa1a78e5d24b-dirty #55 [ 86.516752] Hardware name: Unknown Unknown Product/Unknown Product, BIOS 2022.10 10/01/2022 [ 86.517960] Call trace: [ 86.518333] show_stack+0x20/0x38 (C) [ 86.518891] dump_stack_lvl+0x90/0xd0 [ 86.519443] print_report+0xf8/0x5b0 [ 86.519985] kasan_report+0xb4/0x100 [ 86.520526] __asan_report_load8_noabort+0x20/0x30 [ 86.521240] drm_atomic_helper_shutdown+0x33c/0x378 [ 86.521966] mtk_drm_shutdown+0x54/0x80 [ 86.522546] platform_shutdown+0x64/0x90 [ 86.523137] device_shutdown+0x260/0x5b8 [ 86.523728] kernel_restart+0x78/0xf0 [ 86.524282] __do_sys_reboot+0x258/0x2f0 [ 86.524871] __arm64_sys_reboot+0x90/0xd8 [ 86.525473] invoke_syscall+0x74/0x268 [ 86.526041] el0_svc_common.constprop.0+0xb0/0x240 [ 86.526751] do_el0_svc+0x4c/0x70 [ 86.527251] el0_svc+0x4c/0xc0 [ 86.527719] el0t_64_sync_handler+0x144/0x168 [ 86.528367] el0t_64_sync+0x198/0x1a0 [ 86.528920] [ 86.529157] The buggy address belongs to the physical page: [ 86.529972] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff0000d46fd4d0 pfn:0x1146fc [ 86.531319] flags: 0xbfffc0000000000(node=0|zone=2|lastcpupid=0xffff) [ 86.532267] raw: 0bfffc0000000000 0000000000000000 dead000000000122 0000000000000000 [ 86.533390] raw: ffff0000d46fd4d0 0000000000000000 00000000ffffffff 0000000000000000 [ 86.534511] page dumped because: kasan: bad access detected [ 86.535323] [ 86.535559] Memory state around the buggy address: [ 86.536265] ffff0000d46fbf00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 86.537314] ffff0000d46fbf80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 86.538363] >ffff0000d46fc000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 86.544733] ^ [ 86.551057] ffff0000d46fc080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 86.557510] ffff0000d46fc100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 86.563928] ================================================================== [ 86.571093] Disabling lock debugging due to kernel taint [ 86.577642] Unable to handle kernel paging request at virtual address e0e9c0920000000b [ 86.581834] KASAN: maybe wild-memory-access in range [0x0752049000000058-0x075204900000005f] ... Fixes: 1ef7ed48356c ("drm/mediatek: Modify mediatek-drm for mt8195 multi mmsys support") Signed-off-by: Guoqing Jiang Reviewed-by: AngeloGioacchino Del Regno --- V2 changes: 1. add Fixes tag per CK's comment drivers/gpu/drm/mediatek/mtk_drm_drv.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c index 9a8ef8558da9..0062374f75d5 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c @@ -673,6 +673,8 @@ static int mtk_drm_bind(struct device *dev) err_free: private->drm = NULL; drm_dev_put(drm); + for (i = 0; i < private->data->mmsys_dev_num; i++) + private->all_drm_private[i]->drm = NULL; return ret; }