From: Dan Carpenter <dan.carpenter@xxxxxxxxxx> [ Upstream commit 98f681b0f84cfc3a1d83287b77697679e0398306 ] Smatch complains about "head->full_size - head->header_size" can underflow. To some extent, we're always going to have to trust the firmware a bit. However, it's easy enough to add a check for negatives, and let's add a upper bounds check as well. Fixes: d2458baa799f ("ASoC: SOF: ipc3-loader: Implement firmware parsing and loading") Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Link: https://msgid.link/r/5593d147-058c-4de3-a6f5-540ecb96f6f8@moroto.mountain Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- sound/soc/sof/ipc3-loader.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/sound/soc/sof/ipc3-loader.c b/sound/soc/sof/ipc3-loader.c index 28218766d2114..6e3ef06721106 100644 --- a/sound/soc/sof/ipc3-loader.c +++ b/sound/soc/sof/ipc3-loader.c @@ -148,6 +148,8 @@ static size_t sof_ipc3_fw_parse_ext_man(struct snd_sof_dev *sdev) head = (struct sof_ext_man_header *)fw->data; remaining = head->full_size - head->header_size; + if (remaining < 0 || remaining > sdev->basefw.fw->size) + return -EINVAL; ext_man_size = ipc3_fw_ext_man_size(sdev, fw); /* Assert firmware starts with extended manifest */ -- 2.43.0