From: Wei Chen <harperchen1110@gmail.com>
To: mchehab@kernel.org
Cc: zhongbaisong@huawei.com, linux-media@vger.kernel.org,
linux-kernel@vger.kernel.org, Wei Chen <harperchen1110@gmail.com>
Subject: [PATCH] media: dvb-usb: az6027: Fix three null-ptr-deref in az6027_i2c_xfer()
Date: Fri, 10 Mar 2023 16:56:04 +0000 [thread overview]
Message-ID: <20230310165604.3093483-1-harperchen1110@gmail.com> (raw)
In az6027_i2c_xfer, msg is controlled by user. When msg[i].buf is null,
commit 0ed554fd769a ("media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()")
fix the null-ptr-deref bug when msg[i].addr is 0x99. However, null-ptr-deref
also happens when msg[i].addr is 0xd0 and 0xc0. We add check on msg[i].len to
prevent null-ptr-deref.
Signed-off-by: Wei Chen <harperchen1110@gmail.com>
---
drivers/media/usb/dvb-usb/az6027.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/media/usb/dvb-usb/az6027.c b/drivers/media/usb/dvb-usb/az6027.c
index 7d78ee09be5e..a31c6f82f4e9 100644
--- a/drivers/media/usb/dvb-usb/az6027.c
+++ b/drivers/media/usb/dvb-usb/az6027.c
@@ -988,6 +988,10 @@ static int az6027_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], int n
/* write/read request */
if (i + 1 < num && (msg[i + 1].flags & I2C_M_RD)) {
req = 0xB9;
+ if (msg[i].len < 1) {
+ i = -EOPNOTSUPP;
+ break;
+ }
index = (((msg[i].buf[0] << 8) & 0xff00) | (msg[i].buf[1] & 0x00ff));
value = msg[i].addr + (msg[i].len << 8);
length = msg[i + 1].len + 6;
@@ -1001,6 +1005,10 @@ static int az6027_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], int n
/* demod 16bit addr */
req = 0xBD;
+ if (msg[i].len < 1) {
+ i = -EOPNOTSUPP;
+ break;
+ }
index = (((msg[i].buf[0] << 8) & 0xff00) | (msg[i].buf[1] & 0x00ff));
value = msg[i].addr + (2 << 8);
length = msg[i].len - 2;
@@ -1026,6 +1034,10 @@ static int az6027_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], int n
} else {
req = 0xBD;
+ if (msg[i].len < 1) {
+ i = -EOPNOTSUPP;
+ break;
+ }
index = msg[i].buf[0] & 0x00FF;
value = msg[i].addr + (1 << 8);
length = msg[i].len - 1;
--
2.25.1
reply other threads:[~2023-03-10 16:58 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20230310165604.3093483-1-harperchen1110@gmail.com \
--to=harperchen1110@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-media@vger.kernel.org \
--cc=mchehab@kernel.org \
--cc=zhongbaisong@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®