[PATCH 6.12 179/567] media: dvb-usb: dtv5100: fix out-of-bounds in dtv5100_i2c_msg()

Greg Kroah-Hartman
2026-01-06T17:25:58Z

From: Jeongjun Park <aha310510@gmail.com>

commit b91e6aafe8d356086cc621bc03e35ba2299e4788 upstream.

rlen value is a user-controlled value, but dtv5100_i2c_msg() does not
check the size of the rlen value. Therefore, if it is set to a value
larger than sizeof(st->data), an out-of-bounds vuln occurs for st->data.

Therefore, we need to add proper range checking to prevent this vuln.

Fixes: 60688d5e6e6e ("V4L/DVB (8735): dtv5100: replace dummy frontend by zl10353")
Cc: stable@vger.kernel.org
Signed-off-by: Jeongjun Park <aha310510@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/media/usb/dvb-usb/dtv5100.c | 5 +++++
1 file changed, 5 insertions(+)

--- a/drivers/media/usb/dvb-usb/dtv5100.c
+++ b/drivers/media/usb/dvb-usb/dtv5100.c
@@ -55,6 +55,11 @@ static int dtv5100_i2c_msg(struct dvb_us
}
index = (addr << 8) + wbuf[0];

+ if (rlen > sizeof(st->data)) {
+ warn("rlen = %x is too big!\n", rlen);
+ return -EINVAL;
+ }
+
memcpy(st->data, rbuf, rlen);
msleep(1); /* avoid I2C errors */
return usb_control_msg(d->udev, pipe, request,