From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 7D45832937A; Sat, 30 May 2026 16:29:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780158587; cv=none; b=pVywzC0cPIUTSyzOFjrdjqM+Ve582T7r/J+XXSAAtc6Y1sUBjn9cA06/sxLM5GY8rIY/KpIcLsTvYvWx8uN92t//VUR4hYsYu6uTblJqaWMCWEaCsY51MWNQfhWWLwq9Mk8QZwT1E1Idj4/GRSk1mhhT3ZXny3Zp3T+rHMoFpLg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780158587; c=relaxed/simple; bh=vf4ToYmF4BoujjSdZNchFx8nhUk3+1Vy7NKE7YArqGM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=f/AQ9a3KAgY2p6wGgcyXvaOiCfo8AtfA09Uj4lxhhubZhpR7VqZsfi77CNobbcC2temyPlRN2WoF6dixuhHtvDRev4z6ns7yJYTHrE/KJuwV8008fzh4WToyk93xdTiyxQwpCq2jTJBby1DEr3JEEBiET/j8v80fdWhTesJhdZQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=wPNFrjm9; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="wPNFrjm9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3BDF41F00893; Sat, 30 May 2026 16:29:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780158586; bh=UP02N3Glkl39GEuFH/ZhLhIWnPH8k57PKM8vtYw/XRc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=wPNFrjm9qY/3QQEpCk4OClfzahmfQTSAaEETsyYSujy9L3oq09EzEgn7ENfC8n/WO R+0J5L8i9enkGPnMINE+t545IWkGxXnabKhrv005/lnqn0WiU8ioX/By85OfJLyPPY hTTgmpJGhJ3A+4x741XN1kiHzLyEMWVbpGFVtCWM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Pengpeng Hou , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.1 036/969] nfc: s3fwrn5: allocate rx skb before consuming bytes Date: Sat, 30 May 2026 17:52:40 +0200 Message-ID: <20260530160301.424244416@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160300.485627683@linuxfoundation.org> References: <20260530160300.485627683@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Pengpeng Hou [ Upstream commit 5c14a19d5b1645cce1cb1252833d70b23635b632 ] s3fwrn82_uart_read() reports the number of accepted bytes to the serdev core. The current code consumes bytes into recv_skb and may already deliver a complete frame before allocating a fresh receive buffer. If that alloc_skb() fails, the callback returns 0 even though it has already consumed bytes, and it leaves recv_skb as NULL for the next receive callback. That breaks the receive_buf() accounting contract and can also lead to a NULL dereference on the next skb_put_u8(). Allocate the receive skb lazily before consuming the next byte instead. If allocation fails, return the number of bytes already accepted. Fixes: 3f52c2cb7e3a ("nfc: s3fwrn5: Support a UART interface") Signed-off-by: Pengpeng Hou Link: https://patch.msgid.link/20260402042148.65236-1-pengpeng@iscas.ac.cn Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/nfc/s3fwrn5/uart.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/nfc/s3fwrn5/uart.c b/drivers/nfc/s3fwrn5/uart.c index 82ea35d748a5d..dde1a87ed1e47 100644 --- a/drivers/nfc/s3fwrn5/uart.c +++ b/drivers/nfc/s3fwrn5/uart.c @@ -59,6 +59,12 @@ static int s3fwrn82_uart_read(struct serdev_device *serdev, size_t i; for (i = 0; i < count; i++) { + if (!phy->recv_skb) { + phy->recv_skb = alloc_skb(NCI_SKB_BUFF_LEN, GFP_KERNEL); + if (!phy->recv_skb) + return i; + } + skb_put_u8(phy->recv_skb, *data++); if (phy->recv_skb->len < S3FWRN82_NCI_HEADER) @@ -70,9 +76,7 @@ static int s3fwrn82_uart_read(struct serdev_device *serdev, s3fwrn5_recv_frame(phy->common.ndev, phy->recv_skb, phy->common.mode); - phy->recv_skb = alloc_skb(NCI_SKB_BUFF_LEN, GFP_KERNEL); - if (!phy->recv_skb) - return 0; + phy->recv_skb = NULL; } return i; -- 2.53.0