[PATCH][next] cxl/core: Fix a deference of a pointer cxl_port before it is null checked

From: Colin King
Date: Sun Aug 29 2021 - 13:15:57 EST


From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

The assignment of pointer port with a dereference of pointer cxl_port
occurs before cxl_port is null checked. Fix this by only assigning port
once cxl_port has been null checked.

Addresses-Coverity: ("Dereference before null check")
Fixes: b7ca54b62551 ("cxl/core: Split decoder setup into alloc + add")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
---
drivers/cxl/core/bus.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/cxl/core/bus.c b/drivers/cxl/core/bus.c
index 0b85351be6bf..55db46ba8a18 100644
--- a/drivers/cxl/core/bus.c
+++ b/drivers/cxl/core/bus.c
@@ -494,7 +494,7 @@ EXPORT_SYMBOL_GPL(cxl_decoder_alloc);
int devm_cxl_add_decoder(struct device *host, struct cxl_decoder *cxld,
int *target_map)
{
- struct cxl_port *port = to_cxl_port(cxld->dev.parent);
+ struct cxl_port *port;
struct device *dev;
int rc = 0, i;

@@ -509,6 +509,7 @@ int devm_cxl_add_decoder(struct device *host, struct cxl_decoder *cxld,
goto err;
}

+ port = to_cxl_port(cxld->dev.parent);
device_lock(&port->dev);
if (list_empty(&port->dports))
rc = -EINVAL;
--
2.32.0