[PATCH 5/9] EDAC/versalnet: Use dev_set_name() instead of sprintf with init_name

[Shubhrajyoti Datta]

The previous code used sprintf() to format a device name into a local
stack buffer and then assigned it to dev->init_name. Since kobject
cleanup can be deferred asynchronously (e.g. when
CONFIG_DEBUG_KOBJECT_RELEASE is enabled), dev_name(dev) could be
accessed after init_one_mc() returns and the stack frame containing the
name buffer is gone, resulting in a use-after-free.

This is fixed by switching to dev_set_name(), which dynamically
allocates and manages the name string internally, but the now-unused
local char name[MC_NAME_LEN] buffer and the MC_NAME_LEN macro are
not needed so remove them.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxx>
---

 drivers/edac/versalnet_edac.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/edac/versalnet_edac.c b/drivers/edac/versalnet_edac.c
index 3c9eaea5a106..1caaba653fc0 100644
--- a/drivers/edac/versalnet_edac.c
+++ b/drivers/edac/versalnet_edac.c
@@ -70,8 +70,6 @@
 #define XDDR5_BUS_WIDTH_32		1
 #define XDDR5_BUS_WIDTH_16		2
 
-#define MC_NAME_LEN			32
-
 /**
  * struct ecc_error_info - ECC error log information.
  * @burstpos:		Burst position.
@@ -782,7 +780,6 @@ static int init_one_mc(struct mc_priv *priv, int i)
 	u32 num_chans, rank, dwidth, config;
 	struct edac_mc_layer layers[2];
 	struct mem_ctl_info *mci;
-	char name[MC_NAME_LEN];
 	struct device *dev;
 	enum dev_type dt;
 	int rc = -ENOMEM;
@@ -821,9 +818,7 @@ static int init_one_mc(struct mc_priv *priv, int i)
 	if (!dev)
 		return rc;
 
-	sprintf(name, "versal-net-ddrmc5-edac-%d", i);
 
-	dev->init_name = name;
 	dev->release = versal_edac_release;
 	device_initialize(dev);
 
@@ -833,6 +828,10 @@ static int init_one_mc(struct mc_priv *priv, int i)
 		goto err_put_dev;
 	}
 
+	rc = dev_set_name(dev, "versal-net-ddrmc5-edac-%d", i);
+	if (rc)
+		goto err_mc_free;
+
 	rc = device_add(dev);
 	if (rc)
 		goto err_mc_free;
-- 
2.34.1