From 6ab7ea4e17d6a605d05308adf8f3408924770cba Mon Sep 17 00:00:00 2001 From: Zhang Shurong Date: Sun, 9 Jul 2023 00:28:17 +0800 Subject: [PATCH] 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 Signed-off-by: Hans Verkuil Signed-off-by: Sasha Levin --- drivers/media/usb/dvb-usb-v2/az6007.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/media/usb/dvb-usb-v2/az6007.c b/drivers/media/usb/dvb-usb-v2/az6007.c index 7524c90..6cbfe75 100644 --- a/drivers/media/usb/dvb-usb-v2/az6007.c +++ b/drivers/media/usb/dvb-usb-v2/az6007.c @@ -788,6 +788,10 @@ 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); @@ -802,6 +806,10 @@ 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; -- 2.7.4