On 2020-04-30 08:02, Jeffrey Hugo wrote:
On 4/29/2020 2:52 PM, Bhaumik Bhatt wrote:
Add a bounds check in the firmware copy routine to exit if a malformed
vector table is found while attempting to load the firmware in to the
BHIe vector table.
Signed-off-by: Bhaumik Bhatt <bbh...@codeaurora.org>
---
drivers/bus/mhi/core/boot.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/bus/mhi/core/boot.c b/drivers/bus/mhi/core/boot.c
index 17c636b..bc70edc 100644
--- a/drivers/bus/mhi/core/boot.c
+++ b/drivers/bus/mhi/core/boot.c
@@ -362,8 +362,14 @@ static void mhi_firmware_copy(struct
mhi_controller *mhi_cntrl,
int i = 0;
struct mhi_buf *mhi_buf = img_info->mhi_buf;
struct bhi_vec_entry *bhi_vec = img_info->bhi_vec;
+ struct device *dev = &mhi_cntrl->mhi_dev->dev;
while (remainder) {
+ if (WARN_ON(i >= img_info->entries)) {
+ dev_err(dev, "Malformed vector table\n");
I feel like this message needs more detail. At a minimum, I think it
should indicate what vector table (BHIe). I think if you can identify
what file, etc the the glitch is in, that would be better. Maybe some
detail about i and img_info->entries.
If I see this error message, I should have enough information to
immediately debug the issue. If it tells enough to go directly into
the firmware file and have a look at entry X to see what might be
corrupt about it, that makes my debugging very efficient. If I have
to go back to the code to figure out what "Malformed vector table"
means, and then maybe apply a patch to get more data about the error -
the error message is not as useful as it should be.
I plan on dropping this patch as it looks like an unnecessary check
since we
will always rely on the firmware->size from the request_firmware() API
in order
to calculate the img_info->entries (or we can call it the number of
segments, in
our case). And we will never fail in the if loop as values will already
be
bounded.
+ return;
+ }
+
to_cpy = min(remainder, mhi_buf->len);
memcpy(mhi_buf->buf, buf, to_cpy);
bhi_vec->dma_addr = mhi_buf->dma_addr;
