Re: [lvc-project] [PATCH] remoteproc: imx_rproc: Adjust phandle parsing issue while remapping optional addresses in imx_rproc_addr_init()

[Aleksandr Mishin]

On 11.06.2024 19:45, Mathieu Poirier wrote:

On Mon, Jun 10, 2024 at 08:36:19PM +0300, Fedor Pchelkin wrote:

On Mon, 10. Jun 10:47, Mathieu Poirier wrote:

On Thu, Jun 06, 2024 at 10:52:04AM +0300, Aleksandr Mishin wrote:

In imx_rproc_addr_init() "nph = of_count_phandle_with_args()" just counts
number of phandles. But phandles may be empty. So of_parse_phandle() in
the parsing loop (0 < a < nph) may return NULL which is later dereferenced.
Adjust this issue by adding NULL-return check.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: a0ff4aa6f010 ("remoteproc: imx_rproc: add a NXP/Freescale imx_rproc 
driver")
Signed-off-by: Aleksandr Mishin <amis...@t-argos.ru>
---
  drivers/remoteproc/imx_rproc.c | 2 ++
  1 file changed, 2 insertions(+)

diff --git a/drivers/remoteproc/imx_rproc.c b/drivers/remoteproc/imx_rproc.c
index 5a3fb902acc9..39eacd90af14 100644
--- a/drivers/remoteproc/imx_rproc.c
+++ b/drivers/remoteproc/imx_rproc.c
@@ -726,6 +726,8 @@ static int imx_rproc_addr_init(struct imx_rproc *priv,
                struct resource res;

node = of_parse_phandle(np, "memory-region", a);

+               if (!node)

You're missing an "of_node_put()" before continuing.

The node is NULL in this case so of_node_put() is not needed..?

Oh yeah, doing a of_node_put() with a NULL value is are really good idea...

I will pickup this patch.

Btw, there is a "rsc-table" node->name check in the the end of the loop
body. It was added recently with commit 5e4c1243071d ("remoteproc:
imx_rproc: support remote cores booted before Linux Kernel"). Seems to me
it forgot that of_node_put() is called way before that.

I agree.

Also commit 61afafe8b938 ("remoteproc: imx_rproc: Fix refcount leak in
imx_rproc_addr_init") was dealing with the last of_node_put() call here
but it's still not in the right place I'd say.

You mean becaue of node->name being used after the last of_node_put() or is
there something else?

Aleksandr - Can you send another patch for the above?

Patch is sent.
https://lore.kernel.org/all/20240612131714.12907-1-amis...@t-argos.ru/

Thanks,
Mathieu

+                       continue;
                /* Not map vdevbuffer, vdevring region */
                if (!strncmp(node->name, "vdev", strlen("vdev"))) {
                        of_node_put(node);
--
2.30.2

--
Kind regards
Aleksandr