From nobody Fri Apr 3 20:54:51 2026 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 4832A3988EB; Mon, 23 Mar 2026 12:17:18 +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=1774268241; cv=none; b=dmmvve2Oc3tA7H/l99aFZ7V36wsVnV5TaUJIAzGq50fgLgn7LdmQoRQPmPFAiHWRYo6+moy4+wcFe+iJ7z87Mvi528DkvGMEHwdiHiYVT6yAETQth1uLrrukx2Bslx1yU/kSHMFo4EHLVjE3J8Uzt9uYdcN0lIrOwgdzxfAWNZc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774268241; c=relaxed/simple; bh=6Uov2+PW9/M/oe3iDa1DE2p+e19tzWdz1aw1mX/WKu8=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=sh1YNeRdFBBjTdKB1SLbnEP/nRRSPbyrKCJWkNoIJo1YzKNTtHlKZubNuYUktNVEzz9I97XLnasv2M4XINncnlYm37UCwxJ/M2EtPWnDBrY7hU+DjVlB9qtXHnbMZod91QLQ99vNZVqCi9o08X0UMEzQua5LnQeo+avGKs0fpHY= 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 rQCowAAnSeBLL8FpzImMCw--.60661S2; Mon, 23 Mar 2026 20:17:16 +0800 (CST) From: Pengpeng Hou To: dmitry.torokhov@gmail.com Cc: andriy.shevchenko@linux.intel.com, kees@kernel.org, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, pengpeng@iscas.ac.cn Subject: [PATCH] Input: penmount: bound packet buffer indices in IRQ path Date: Mon, 23 Mar 2026 20:17:15 +0800 Message-ID: <20260323121715.74954-1-pengpeng@iscas.ac.cn> X-Mailer: git-send-email 2.50.1 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 X-CM-TRANSID: rQCowAAnSeBLL8FpzImMCw--.60661S2 X-Coremail-Antispam: 1UD129KBjvdXoWrZr45uw4rurWrAFWfAFWrXwb_yoWkJwcE9r y8JF95Gw1UCrZF9wnFkry3ZryS9FW2vFykZw13Krs5Gry5X39xta95A3Z3ArWDCw47tr45 C3y7XryxZ34xKjkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUb48FF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2IYs7xG 6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8w A2z4x0Y4vE2Ix0cI8IcVAFwI0_Gr0_Xr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr0_ Cr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_GcCE3s 1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0 cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r4j6F4UMcvjeVCFs4IE7xkEbVWUJVW8Jw ACjcxG0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1lc7CjxVAaw2AFwI0_JF0_ Jw1l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxV WUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r126r1DMIIYrxkI 7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26r 1j6r4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVW8JVWxJwCI 42IY6I8E87Iv6xkF7I0E14v26r4UJVWxJrUvcSsGvfC2KfnxnUUI43ZEXa7VUjO6pDUUUU U== X-CM-SenderInfo: pshqw1xhqjqxpvfd2hldfou0/ Content-Type: text/plain; charset="utf-8" The IRQ handler stores each incoming byte into pm->data[] before the packet parser gets a chance to reset pm->idx. If the incoming serial stream never matches one of the expected packet headers, pm->idx can advance past the fixed receive buffer and the next IRQ will write beyond PM_MAX_LENGTH. Reset stale indices before writing the next byte so malformed packet streams cannot walk past the end of the local packet buffer. Signed-off-by: Pengpeng Hou --- drivers/input/touchscreen/penmount.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/input/touchscreen/penmount.c b/drivers/input/touchscre= en/penmount.c index 4b57b6664e37..ba09096c6573 100644 --- a/drivers/input/touchscreen/penmount.c +++ b/drivers/input/touchscreen/penmount.c @@ -163,6 +163,9 @@ static irqreturn_t pm_interrupt(struct serio *serio, { struct pm *pm =3D serio_get_drvdata(serio); =20 + if (pm->idx >=3D pm->packetsize || pm->idx >=3D PM_MAX_LENGTH) + pm->idx =3D 0; + pm->data[pm->idx] =3D data; =20 pm->parse_packet(pm); --=20 2.50.1 (Apple Git-155)