From nobody Mon Apr 6 09:13:43 2026 Received: from cstnet.cn (smtp25.cstnet.cn [159.226.251.25]) (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 A300F37DEAD; Sun, 22 Mar 2026 03:19:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=159.226.251.25 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774149579; cv=none; b=BymPYcS9ptSacoT//lIYxAw8NfN2ozv16hzV4XjMLC/nMr2g8quSUuSTIHwTJTZT1YxeQCaZrp1Qmga/7lz7hQVvsx2EKiLtnkOMh7HNdKTGNXqQWIu4wuuZQsdxO+YkP7s3W7KSKzFQPjS6dZvWUXM7Dx/2Iy+q6KIdpe1yMKo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774149579; c=relaxed/simple; bh=dRRHJP/o97UdiIWF7mfrp2KAzhmcDLpnzYSFg3fB5E0=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=bYJLTWDmCecvhm+3Fckzq/Gk51XHYsJB8C9BTzUmmRHb8246DlvCxbvGGgASRN46w3H3nUoh+6/fZD+04rixcKdKwgrRW6Iy4urvzBwHUfvkZbmp8/TlFdLgAXZwvPbH2sUI+xlI7g/UFlLR1o5M2wiKwFdK1+cmMykITNtRSI0= 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=159.226.251.25 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-05 (Coremail) with SMTP id zQCowAAXpQi7X79p2k8eCw--.33030S2; Sun, 22 Mar 2026 11:19:24 +0800 (CST) From: Pengpeng Hou To: linux-iio@vger.kernel.org Cc: pengpeng@iscas.ac.cn, Gyeyoung Baek , Jonathan Cameron , David Lechner , =?UTF-8?q?Nuno=20S=C3=A1?= , Andy Shevchenko , linux-kernel@vger.kernel.org Subject: [PATCH] iio: chemical: mhz19b: bound receive buffer copy Date: Sun, 22 Mar 2026 11:19:23 +0800 Message-ID: <20260322031923.58031-1-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: zQCowAAXpQi7X79p2k8eCw--.33030S2 X-Coremail-Antispam: 1UD129KBjvdXoW7Jr47AF15CrWkWw1UZF1rtFb_yoWDKrb_C3 W8Arn7urW5GFnrKan2vF1a9ryaya9F9F17Wa1avFy3Gry2qFn7Zw1kZrsxKrsxuFWI9Fnr Xw4DWF1Svry3CjkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUb4xFF20E14v26r4j6ryUM7CY07I20VC2zVCF04k26cxKx2IYs7xG 6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8w A2z4x0Y4vE2Ix0cI8IcVAFwI0_Gr0_Xr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr0_ Cr1l84ACjcxK6I8E87Iv67AKxVWxJr0_GcWl84ACjcxK6I8E87Iv6xkF7I0E14v26F4UJV W0owAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0 I7IYx2IY67AKxVWUAVWUtwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r 4UM4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwCY1x0262kKe7AKxVWU AVWUtwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14 v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIxkG c2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI 0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4U MIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x0JUmjgxUUU UU= X-CM-SenderInfo: pshqw1xhqjqxpvfd2hldfou0/ Content-Type: text/plain; charset="utf-8" `mhz19b_receive_buf()` appends bytes to the fixed 9-byte command buffer without first checking that the new chunk fits in the remaining space. A single receive callback can therefore write past the end of `st->buf` before the driver sees that the command is complete. Drop overlong chunks and reset the partial command state before the copy. Signed-off-by: Pengpeng Hou Acked-by: Gyeyoung Baek --- drivers/iio/chemical/mhz19b.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/iio/chemical/mhz19b.c b/drivers/iio/chemical/mhz19b.c index 3c64154918b1..a028216fa2a9 100644 --- a/drivers/iio/chemical/mhz19b.c +++ b/drivers/iio/chemical/mhz19b.c @@ -241,6 +241,11 @@ static size_t mhz19b_receive_buf(struct serdev_device = *serdev, struct iio_dev *indio_dev =3D dev_get_drvdata(&serdev->dev); struct mhz19b_state *st =3D iio_priv(indio_dev); =20 + if (len > sizeof(st->buf) - st->buf_idx) { + st->buf_idx =3D 0; + return len; + } + memcpy(st->buf + st->buf_idx, data, len); st->buf_idx +=3D len; =20 --=20 2.50.1 (Apple Git-155)