Bluetooth: btbcm: Fix NULL deref in btbcm_get_board_name()

JIRA: https://issues.redhat.com/browse/RHEL-81375
CVE: CVE-2024-57988

commit b88655b
Author: Charles Han <hanchunchao@inspur.com>
Date:   Fri Dec 27 17:20:46 2024 +0800

    Bluetooth: btbcm: Fix NULL deref in btbcm_get_board_name()

    devm_kstrdup() can return a NULL pointer on failure,but this
    returned value in btbcm_get_board_name() is not checked.
    Add NULL check in btbcm_get_board_name(), to handle kernel NULL
    pointer dereference error.

    Fixes: f9183ea ("Bluetooth: btbcm: Use devm_kstrdup()")
    Signed-off-by: Charles Han <hanchunchao@inspur.com>
    Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

Signed-off-by: CKI Backport Bot <cki-ci-bot+cki-gitlab-backport-bot@redhat.com>

Author: CKI Backport Bot

drivers/bluetooth/btbcm.c

@@ -554,6 +554,9 @@ static const char *btbcm_get_board_name(struct device *dev)
 
 	/* get rid of any '/' in the compatible string */
 	board_type = devm_kstrdup(dev, tmp, GFP_KERNEL);
+	if (!board_type)
+		return NULL;
+
 	strreplace(board_type, '/', '-');
 	of_node_put(root);