From cc2766399882001880a899e723c7bd968e60f100 Mon Sep 17 00:00:00 2001

From: Vishal Verma <vishal.l.verma@intel.com>

Date: Tue, 23 Aug 2022 01:45:25 -0600

Subject: [PATCH 214/217] cxl/region: fix a dereferecnce after NULL check

A NULL check in region_action() implies that 'decoder' might be NULL, but

later we dereference it during cxl_decoder_foreach(). The NULL check is

valid because it was the filter result being checked, however, while

doing this, the original 'decoder' variable was being clobbered.

Check the filter results independently of the original decoder variable.

Link: https://lore.kernel.org/r/20220823074527.404435-2-vishal.l.verma@intel.com

Cc: Dan Williams <dan.j.williams@intel.com>

Reviewed-by: Dan Williams <dan.j.williams@intel.com>

Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>

---

 cxl/region.c | 5 ++---

 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/cxl/region.c b/cxl/region.c

index a30313c..334fcc2 100644

--- a/cxl/region.c

+++ b/cxl/region.c

@@ -686,9 +686,8 @@ static int region_action(int argc, const char **argv, struct cxl_ctx *ctx,

 			continue;

 		cxl_decoder_foreach (port, decoder) {

-			decoder = util_cxl_decoder_filter(decoder,

-							  param.root_decoder);

-			if (!decoder)

+			if (!util_cxl_decoder_filter(decoder,

+						     param.root_decoder))

 				continue;

 			rc = decoder_region_action(p, decoder, action, count);

 			if (rc)

-- 

2.27.0