From nobody Sat Jul 25 18:13:12 2026 Received: from mailgw.kylinos.cn (mailgw.kylinos.cn [124.126.103.232]) (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 F3E61219E8; Wed, 15 Jul 2026 03:04:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=124.126.103.232 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784084655; cv=none; b=IVFK+oQKc7HD38NL5t7O36OWjZKcsNmyBVf5A95/FSbQ8bpgCiz2+6xjkjUXfp057A06OjCfNzPEXhnaR/3Seskv+jz3mQHaYG+PUdm8QszLqSd9o8m0fDO3VuAl3gKB2A9pqetuZKqlkIfccccW0zCxLgnN+qHrgrawG6SHGMw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784084655; c=relaxed/simple; bh=ScCweytatJ5WqByC2hb5e/coXq8Ygcc18j17m/AHxaQ=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=ms0IkP5zUY0Us4fHK0koErmFlG98CGmCbAdZiJn24O9jhH8qrVradQBJMtDCVx7Ws509YKXgoEC/mpMA9u++CeCESomffoLP37uvEK+45yx/xA0K3c3zDF1WG1gjqNsw1P+l9jb0SRmve0T+j0KDmdCgcK3ufsPdBze1i6P43LE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn; spf=pass smtp.mailfrom=kylinos.cn; arc=none smtp.client-ip=124.126.103.232 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kylinos.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kylinos.cn X-UUID: d8d1016a7ff911f1aa26b74ffac11d73-20260715 X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.3.12,REQID:dbfe8127-73bb-42b7-9c04-fce0542fd79b,IP:0,U RL:0,TC:0,Content:-25,EDM:0,RT:0,SF:0,FILE:0,BULK:0,RULE:Release_Ham,ACTIO N:release,TS:-25 X-CID-META: VersionHash:e7bac3a,CLOUDID:ab5065c90ca99b1495b1671d02a227e0,BulkI D:nil,BulkQuantity:0,Recheck:0,SF:102|850|865|898,TC:nil,Content:0|15|50,E DM:-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: 2,SSN|SDN X-CID-BAS: 2,SSN|SDN,0,_ X-CID-FACTOR: TF_CID_SPAM_SNR X-CID-RHF: D41D8CD98F00B204E9800998ECF8427E X-UUID: d8d1016a7ff911f1aa26b74ffac11d73-20260715 X-User: yijiangshan@kylinos.cn Received: from localhost.localdomain [(10.44.16.150)] by mailgw.kylinos.cn (envelope-from ) (Generic MTA with TLSv1.3 TLS_AES_256_GCM_SHA384 256/256) with ESMTP id 332420658; Wed, 15 Jul 2026 11:04:08 +0800 From: Jiangshan Yi To: andy@kernel.org, gregkh@linuxfoundation.org, jirislaby@kernel.org Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, 13667453960@163.com, Jiangshan Yi , stable@kernel.org, Andy Shevchenko Subject: [PATCH] serial: 8250_mid: Fix NULL function pointer dereference on DNV/ICX-D/SNR platforms Date: Wed, 15 Jul 2026 11:03:36 +0800 Message-Id: <20260715030336.1512861-1-yijiangshan@kylinos.cn> X-Mailer: git-send-email 2.25.1 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 Content-Type: text/plain; charset="utf-8" Commit b1b4efea05a5 ("serial: 8250_mid: Disable DMA for selected platforms") replaced the dnv_board setup and exit callbacks with PTR_IF(false, ...), which evaluates to NULL. However, the three call sites in mid8250_probe() and mid8250_remove() unconditionally dereference these function pointers without NULL checks, causing a NULL pointer dereference (kernel oops) on any Denverton (DNV), Ice Lake Xeon D (ICX-D/CDF), or Snowridge (SNR) platform. Fix this by adding the missing NULL checks before calling the setup and exit callbacks. Fixes: b1b4efea05a5 ("serial: 8250_mid: Disable DMA for selected platforms") Cc: stable@kernel.org Cc: Andy Shevchenko Cc: Greg Kroah-Hartman Signed-off-by: Jiangshan Yi Reviewed-by: Andy Shevchenko --- drivers/tty/serial/8250/8250_mid.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/tty/serial/8250/8250_mid.c b/drivers/tty/serial/8250/8= 250_mid.c index f88809ff370b..3c43a11ce4c9 100644 --- a/drivers/tty/serial/8250/8250_mid.c +++ b/drivers/tty/serial/8250/8250_mid.c @@ -318,7 +318,7 @@ static int mid8250_probe(struct pci_dev *pdev, const st= ruct pci_device_id *id) if (!uart.port.membase) return -ENOMEM; =20 - ret =3D mid->board->setup(mid, &uart.port); + ret =3D mid->board->setup ? mid->board->setup(mid, &uart.port) : 0; if (ret) return ret; =20 @@ -336,7 +336,8 @@ static int mid8250_probe(struct pci_dev *pdev, const st= ruct pci_device_id *id) return 0; =20 err: - mid->board->exit(mid); + if (mid->board->exit) + mid->board->exit(mid); return ret; } =20 @@ -346,7 +347,8 @@ static void mid8250_remove(struct pci_dev *pdev) =20 serial8250_unregister_port(mid->line); =20 - mid->board->exit(mid); + if (mid->board->exit) + mid->board->exit(mid); } =20 static const struct mid8250_board pnw_board =3D { --=20 2.25.1