This is a note to let you know that I've just added the patch titled
media: af9005: Fix null-ptr-deref in af9005_i2c_xfer
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
media-af9005-fix-null-ptr-deref-in-af9005_i2c_xfer.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit bf780e350197e87f9c2faad8355141dff79e58c8
Author: Zhang Shurong <zhang_shurong@xxxxxxxxxxx>
Date: Sat Jul 8 23:24:11 2023 +0800
media: af9005: Fix null-ptr-deref in af9005_i2c_xfer
[ Upstream commit f4ee84f27625ce1fdf41e8483fa0561a1b837d10 ]
In af9005_i2c_xfer, msg is controlled by user. When msg[i].buf
is null and msg[i].len is zero, former checks on msg[i].buf would be
passed. Malicious data finally reach af9005_i2c_xfer. If accessing
msg[i].buf[0] without sanity check, null ptr deref would happen.
We add check on msg[i].len to prevent crash.
Similar commit:
commit 0ed554fd769a
("media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()")
Signed-off-by: Zhang Shurong <zhang_shurong@xxxxxxxxxxx>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/media/usb/dvb-usb/af9005.c b/drivers/media/usb/dvb-usb/af9005.c
index b6a2436d16e97..9af54fcbed1de 100644
--- a/drivers/media/usb/dvb-usb/af9005.c
+++ b/drivers/media/usb/dvb-usb/af9005.c
@@ -422,6 +422,10 @@ static int af9005_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[],
if (ret == 0)
ret = 2;
} else {
+ if (msg[0].len < 2) {
+ ret = -EOPNOTSUPP;
+ goto unlock;
+ }
/* write one or more registers */
reg = msg[0].buf[0];
addr = msg[0].addr;
@@ -431,6 +435,7 @@ static int af9005_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[],
ret = 1;
}
+unlock:
mutex_unlock(&d->i2c_mutex);
return ret;
}
