1 files changed, 42 insertions, 0 deletions
diff --git a/iwlwifi-properly-check-debugfs-dentry-before-using-it.patch b/iwlwifi-properly-check-debugfs-dentry-before-using-it.patch
new file mode 100644
index 00000000000000..916ecadddda1a7
--- /dev/null
+++ b/iwlwifi-properly-check-debugfs-dentry-before-using-it.patch
@@ -0,0 +1,42 @@
+From foo@baz Sat Mar 30 10:26:34 CET 2019
+Date: Sat, 30 Mar 2019 10:26:34 +0100
+To: Greg KH <gregkh@linuxfoundation.org>
+From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Subject: [PATCH] iwlwifi: properly check debugfs dentry before using it
+
+debugfs can now report an error code if something went wrong instead of
+just NULL.  So if the return value is to be used as a "real" dentry, it
+needs to be checked if it is an error before dereferencing it.
+
+This is now happening because of ff9fb72bc077 ("debugfs: return error
+values, not NULL").  If multiple iwlwifi devices are in the system, this
+can cause problems when the driver attempts to create the main debugfs
+directory again.  Later on in the code we fail horribly by trying to
+dereference a pointer that is an error value.
+
+Reported-by: Laura Abbott <labbott@redhat.com>
+Cc: Johannes Berg <johannes.berg@intel.com>
+Cc: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
+Cc: Luca Coelho <luciano.coelho@intel.com>
+Cc: Intel Linux Wireless <linuxwifi@intel.com>
+Cc: Kalle Valo <kvalo@codeaurora.org>
+Cc: stable <stable@vger.kernel.org> # 5.0
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+
+---
+ drivers/net/wireless/intel/iwlwifi/mvm/debugfs-vif.c |    3 +--
+ 1 file changed, 1 insertion(+), 2 deletions(-)
+
+--- a/drivers/net/wireless/intel/iwlwifi/mvm/debugfs-vif.c
++++ b/drivers/net/wireless/intel/iwlwifi/mvm/debugfs-vif.c
+@@ -774,8 +774,7 @@ void iwl_mvm_vif_dbgfs_register(struct i
+ 		return;
+ 
+ 	mvmvif->dbgfs_dir = debugfs_create_dir("iwlmvm", dbgfs_dir);
+-
+-	if (!mvmvif->dbgfs_dir) {
++	if (IS_ERR_OR_NULL(mvmvif->dbgfs_dir)) {
+ 		IWL_ERR(mvm, "Failed to create debugfs directory under %pd\n",
+ 			dbgfs_dir);
+ 		return;