On Fri, Aug 27, 2021 at 11:35:31PM +0800, butt3rflyh4ck wrote:

On Fri, Aug 27, 2021 at 9:24 PM Dan Carpenter [off-list ref] wrote:

quoted

These checks are still not strict enough.  The main problem is that if
"cb->type == QRTR_TYPE_NEW_SERVER" is true then "len - hdrlen" is
guaranteed to be 4 but we need to be at least 16 bytes.  In fact, we
can reject everything smaller than sizeof(*pkt) which is 20 bytes.

Also I don't like the ALIGN(size, 4).  It's better to just insist that
data is needs to be aligned at the start.

Fixes: 0baa99ee353c ("net: qrtr: Allow non-immediate node routing")
Signed-off-by: Dan Carpenter <redacted>
---
This was from review.  Not tested.

 net/qrtr/qrtr.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/net/qrtr/qrtr.c b/net/qrtr/qrtr.c
index b8508e35d20e..dbb647f5481b 100644
--- a/net/qrtr/qrtr.c
+++ b/net/qrtr/qrtr.c

@@ -493,7 +493,7 @@ int qrtr_endpoint_post(struct qrtr_endpoint *ep, const void *data, size_t len)
                goto err;
        }

quoted

-       if (!size || len != ALIGN(size, 4) + hdrlen)
+       if (!size || size % 3 || len != size + hdrlen)

Hi, (size % 3)  is wrong, is it (size & 3), right ?

Yeah.  Thanks for catching that.  I means & 3.

regards,
dan carpenter