tree 1fb72fc026547fb493cea5f03f52e445a08d5881
parent b35f63972c5c67fc0f908286f7fc624137788876
author Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1553938312 +0100
committer Luca Coelho <luciano.coelho@intel.com> 1555589204 +0300

iwlwifi: mvm: 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>
Reported-by: Gabriel Ramirez <gabriello.ramirez@gmail.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>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>