This is a note to let you know that I've just added the patch titled
media: dvb-usb-v2: gl861: Fix null-ptr-deref in gl861_i2c_master_xfer
to the 6.1-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-dvb-usb-v2-gl861-fix-null-ptr-deref-in-gl861_i.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 52842cbc406b3b0b260db4534ac516e3454dc87a
Author: Zhang Shurong <zhang_shurong@xxxxxxxxxxx>
Date: Mon Jul 10 13:32:13 2023 +0800
media: dvb-usb-v2: gl861: Fix null-ptr-deref in gl861_i2c_master_xfer
[ Upstream commit b97719a66970601cd3151a3e2020f4454a1c4ff6 ]
In gl861_i2c_master_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 gl861_i2c_master_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/gl861.c b/drivers/media/usb/dvb-usb-v2/gl861.c
index 0c434259c36f1..c71e7b93476de 100644
--- a/drivers/media/usb/dvb-usb-v2/gl861.c
+++ b/drivers/media/usb/dvb-usb-v2/gl861.c
@@ -120,7 +120,7 @@ static int gl861_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg msg[],
} else if (num == 2 && !(msg[0].flags & I2C_M_RD) &&
(msg[1].flags & I2C_M_RD)) {
/* I2C write + read */
- if (msg[0].len > 1 || msg[1].len > sizeof(ctx->buf)) {
+ if (msg[0].len != 1 || msg[1].len > sizeof(ctx->buf)) {
ret = -EOPNOTSUPP;
goto err;
}
