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authorWei Chen <harperchen1110@gmail.com>2023-03-13 12:50:08 +0300
committerMauro Carvalho Chehab <mchehab@kernel.org>2023-05-14 08:30:06 +0300
commit9ded5bd2a49ce3015b7c936743eec0a0e6e11f0c (patch)
treefee0471a252bb8933743cea07d4111c8a25085f7 /drivers/media/usb
parentaa4a447b81b84f69c1a89ad899df157f386d7636 (diff)
downloadlinux-9ded5bd2a49ce3015b7c936743eec0a0e6e11f0c.tar.xz
media: dvb-usb: digitv: fix null-ptr-deref in digitv_i2c_xfer()
In digitv_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 digitv_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()") Link: https://lore.kernel.org/linux-media/20230313095008.1039689-1-harperchen1110@gmail.com Signed-off-by: Wei Chen <harperchen1110@gmail.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Diffstat (limited to 'drivers/media/usb')
-rw-r--r--drivers/media/usb/dvb-usb/digitv.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/media/usb/dvb-usb/digitv.c b/drivers/media/usb/dvb-usb/digitv.c
index 2756815a780b..32134be16914 100644
--- a/drivers/media/usb/dvb-usb/digitv.c
+++ b/drivers/media/usb/dvb-usb/digitv.c
@@ -63,6 +63,10 @@ static int digitv_i2c_xfer(struct i2c_adapter *adap,struct i2c_msg msg[],int num
warn("more than 2 i2c messages at a time is not handled yet. TODO.");
for (i = 0; i < num; i++) {
+ if (msg[i].len < 1) {
+ i = -EOPNOTSUPP;
+ break;
+ }
/* write/read request */
if (i+1 < num && (msg[i+1].flags & I2C_M_RD)) {
if (digitv_ctrl_msg(d, USB_READ_COFDM, msg[i].buf[0], NULL, 0,