From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from cstnet.cn (smtp81.cstnet.cn [159.226.251.81]) (using TLSv1.2 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 54FFE35CB61; Mon, 23 Mar 2026 07:24:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=159.226.251.81 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774250656; cv=none; b=YvJoG9ajnj3Ih16tdN00KcwXpCI4ANWDc52cwhjfndE2Lkrf04q2boMc/MC4nRXuHURTXMC+aRPaY/XkcbDuhhzwOMk2hira8jOsAEqXuuWG4LhfZdH4EF1K3SneiHGmm8RHZByMhOuESoGVVYW9LC5dmISUmooVsfnOky945CY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774250656; c=relaxed/simple; bh=/4exprVqxuVfRqJPaNRhfYNkHOpCb6tQ85+amF0cqDE=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=CGTbI5emyA6WXkxM/ZoHXlh+N/b3WxxSmLDR6WLnYd+l7IE74NP4UUjRRfh8xfzuK7MxwQ4cd3gDn7OdiRko+VFd+eBrNZ5MfD3/sDI1T6MHh/bMnef8pFIP5uPXxJ9SBqAh2Z5qizR5jb4J1BJm9nWXW9m4SZNJIQtKh/oLj7E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn; spf=pass smtp.mailfrom=iscas.ac.cn; arc=none smtp.client-ip=159.226.251.81 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=iscas.ac.cn Received: from localhost.localdomain (unknown [111.196.245.197]) by APP-03 (Coremail) with SMTP id rQCowABnieCZ6sBp2FOGCw--.58546S2; Mon, 23 Mar 2026 15:24:10 +0800 (CST) From: Pengpeng Hou To: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org, tglx@kernel.org, mingo@kernel.org, kees@kernel.org, pengpeng@iscas.ac.cn Subject: [PATCH] NFC: pn533: bound the UART receive buffer Date: Mon, 23 Mar 2026 15:24:09 +0800 Message-ID: <20260323072409.60086-1-pengpeng@iscas.ac.cn> X-Mailer: git-send-email 2.50.1 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID:rQCowABnieCZ6sBp2FOGCw--.58546S2 X-Coremail-Antispam: 1UD129KBjvdXoWrKr17JryDtrWxWF1DJFyUGFg_yoWkArcEva 4kA34UJr4UGr1UKw1xtrW5ZryjyayUWF98uF10gFyfAa4jk348CFWkZF9ru345Ww4UZFnx u34UGr1Ik34rujkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUb48FF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2IYs7xG 6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8w A2z4x0Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Cr0_ Gr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s 0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xII jxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr 1lF7xvr2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7MxkF7I0En4kS14v26r12 6r1DMxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI 0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUAVWUtwCIc40Y 0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxV WUJVW8JwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1l IxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7VUjuHq7UUUU U== X-CM-SenderInfo: pshqw1xhqjqxpvfd2hldfou0/ pn532_receive_buf() appends every incoming byte to dev->recv_skb and only resets the buffer after pn532_uart_rx_is_frame() recognizes a complete frame. A continuous stream of bytes without a valid PN532 frame header therefore keeps growing the skb until skb_put_u8() hits the tail limit. Drop the accumulated partial frame once the fixed receive buffer is full so malformed UART traffic cannot grow the skb past PN532_UART_SKB_BUFF_LEN. Signed-off-by: Pengpeng Hou --- drivers/nfc/pn533/uart.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/nfc/pn533/uart.c b/drivers/nfc/pn533/uart.c index 6d2f520a5bc8..1b82b7b2a5fa 100644 --- a/drivers/nfc/pn533/uart.c +++ b/drivers/nfc/pn533/uart.c @@ -211,6 +211,9 @@ static size_t pn532_receive_buf(struct serdev_device *serdev, timer_delete(&dev->cmd_timeout); for (i = 0; i < count; i++) { + if (unlikely(!skb_tailroom(dev->recv_skb))) + skb_trim(dev->recv_skb, 0); + skb_put_u8(dev->recv_skb, *data++); if (!pn532_uart_rx_is_frame(dev->recv_skb)) continue; -- 2.50.1 (Apple Git-155)