From nobody Fri Dec 19 21:48:51 2025 Received: from mailgw01.mediatek.com (unknown [60.244.123.138]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1911A274FE3 for ; Thu, 4 Sep 2025 06:33:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=60.244.123.138 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756967589; cv=none; b=tIrQdiGBim/Zvwpk/Bsq4oHNYERqBrKhIDSpNPdH0mLkObEcf+wCgAAmkAqor3N7SiZ81ljbI5gpFu7xa7DJ193SvtBsUQLIgf4wjI+jBQE4sDXFk5Ekm58GDlQ1GWcpjX5G7sN8SnJrW/qnEPw/izmcdXcX4Kqbv4mF3oqL24g= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756967589; c=relaxed/simple; bh=EcYEj43mL8nM4gr/Yfa810G91+KSmFFHYILwTZHNnHM=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=CafGzmBHb6knuisRuFbqjYAxjXKpyk8yen2nYKUuZRA2+kXPvq42FACPh8i2/vXfPK/kEabJ0fiDij8LNZwJAtIfhk+1vON4piCqIrI5LM4bQNs676BXw9Xx3e0gqAprDK41RXBzKcNH+5tOveduiGPI6iV4nXBBsoKFXcPFBZU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=mediatek.com; spf=pass smtp.mailfrom=mediatek.com; dkim=pass (1024-bit key) header.d=mediatek.com header.i=@mediatek.com header.b=GOSZfhB1; arc=none smtp.client-ip=60.244.123.138 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=mediatek.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mediatek.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=mediatek.com header.i=@mediatek.com header.b="GOSZfhB1" X-UUID: 010f9abc895911f0bd5779446731db89-20250904 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:References:In-Reply-To:Message-ID:Date:Subject:CC:To:From; bh=YpGOZ6R4tA8s0gpQCC9ncHlNVuO9zib3S9+/vzed/sQ=; b=GOSZfhB1S2vrhO3TVkB5u8O6D6D0wbzm+W0DiDCmZ5/gLQkd5+Bigkoi8ii2Z/WaaT3G/LW1eOw3BCIc2/R24leLa6AIvdmiGnno2XnQKW7sQfOFM7Pmk4ElFWOqGE70gh+uoBy7lLcp2W9nlXrOyX6y4pkTmNKgHdjqkNSy4c4=; X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.3.3,REQID:e94d8672-95ee-48db-8b1b-0970ae6764c6,IP:0,UR L:0,TC:0,Content:0,EDM:0,RT:0,SF:0,FILE:0,BULK:0,RULE:Release_Ham,ACTION:r elease,TS:0 X-CID-META: VersionHash:f1326cf,CLOUDID:e3eeeef7-ebfe-43c9-88c9-80cb93f22ca4,B ulkID:nil,BulkQuantity:0,Recheck:0,SF:81|82|102,TC:-5,Content:0|15|50,EDM: -3,IP:nil,URL: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: 3,DMD|SSN|SDN X-CID-BAS: 3,DMD|SSN|SDN,0,_ X-CID-FACTOR: TF_CID_SPAM_SNR X-CID-RHF: D41D8CD98F00B204E9800998ECF8427E X-UUID: 010f9abc895911f0bd5779446731db89-20250904 Received: from mtkmbs09n2.mediatek.inc [(172.21.101.94)] by mailgw01.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 256494133; Thu, 04 Sep 2025 14:33:01 +0800 Received: from mtkmbs11n1.mediatek.inc (172.21.101.185) by MTKMBS09N2.mediatek.inc (172.21.101.94) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.39; Thu, 4 Sep 2025 14:32:58 +0800 Received: from mbjsdccf07.gcn.mediatek.inc (10.15.20.246) by mtkmbs11n1.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.2.1258.39 via Frontend Transport; Thu, 4 Sep 2025 14:32:52 +0800 From: To: Arnd Bergmann , Greg Kroah-Hartman , Matthias Brugger , AngeloGioacchino Del Regno , Akinobu Mita , Andrew Morton CC: , , Xion Wang , , , Subject: [PATCH 1/1] char: Use list_del_init() in misc_deregister() to reinitialize list pointer Date: Thu, 4 Sep 2025 14:37:04 +0800 Message-ID: <20250904063714.28925-2-xion.wang@mediatek.com> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20250904063714.28925-1-xion.wang@mediatek.com> References: <20250904063714.28925-1-xion.wang@mediatek.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-MTK: N Content-Type: text/plain; charset="utf-8" From: Xion Wang Currently, misc_deregister() uses list_del() to remove the device from the list. After list_del(), the list pointers are set to=20 LIST_POISON1 and LIST_POISON2, which may help catch use-after-free bugs, but does not reset the list head. If misc_deregister() is called more than once on the same device, list_empty() will not return true, and list_del() may be called again, leading to undefined behavior. Replace list_del() with list_del_init() to reinitialize the list head after deletion. This makes the code more robust against double deregistration and allows safe usage of list_empty() on the miscdevice after deregistration. Fixes: b329becfc78b1 ("char: add WARN_ON() in misc_deregister()") Signed-off-by: Xion Wang --- drivers/char/misc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/char/misc.c b/drivers/char/misc.c index 558302a64dd9..b5d44b08ad7b 100644 --- a/drivers/char/misc.c +++ b/drivers/char/misc.c @@ -279,7 +279,7 @@ void misc_deregister(struct miscdevice *misc) return; =20 mutex_lock(&misc_mtx); - list_del(&misc->list); + list_del_init(&misc->list); device_destroy(&misc_class, MKDEV(MISC_MAJOR, misc->minor)); misc_minor_free(misc->minor); mutex_unlock(&misc_mtx); --=20 2.45.2