This is a note to let you know that I've just added the patch titled
media: az6007: Fix null-ptr-deref in az6007_i2c_xfer()
to the 4.19-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-az6007-fix-null-ptr-deref-in-az6007_i2c_xfer.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b06c2f7a9264d73587d7e633dd16bd298ce1171c
Author: Zhang Shurong <zhang_shurong@xxxxxxxxxxx>
Date: Sun Jul 9 00:28:17 2023 +0800
media: az6007: Fix null-ptr-deref in az6007_i2c_xfer()
[ Upstream commit 1047f9343011f2cedc73c64829686206a7e9fc3f ]
In az6007_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 az6007_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-v2/az6007.c b/drivers/media/usb/dvb-usb-v2/az6007.c
index 8e914be5b7c5e..2f40eb6bdbb83 100644
--- a/drivers/media/usb/dvb-usb-v2/az6007.c
+++ b/drivers/media/usb/dvb-usb-v2/az6007.c
@@ -796,6 +796,10 @@ static int az6007_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
if (az6007_xfer_debug)
printk(KERN_DEBUG "az6007: I2C W addr=0x%x len=%d\n",
addr, msgs[i].len);
+ if (msgs[i].len < 1) {
+ ret = -EIO;
+ goto err;
+ }
req = AZ6007_I2C_WR;
index = msgs[i].buf[0];
value = addr | (1 << 8);
@@ -810,6 +814,10 @@ static int az6007_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
if (az6007_xfer_debug)
printk(KERN_DEBUG "az6007: I2C R addr=0x%x len=%d\n",
addr, msgs[i].len);
+ if (msgs[i].len < 1) {
+ ret = -EIO;
+ goto err;
+ }
req = AZ6007_I2C_RD;
index = msgs[i].buf[0];
value = addr;
