lkml.org 
[lkml]   [2019]   [Apr]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] iwlwifi: properly check debugfs dentry before using it
From
Date
On 3/30/19 2:31 AM, Greg Kroah-Hartman wrote:
> 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>

Can you add

Reported-by: Gabriel Ramirez <gabriello.ramirez@gmail.com>

for the bugzilla reporter who took the time to do the bisect?
I'll ask for testing as well.

> 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>
>
>
> diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/debugfs-vif.c b/drivers/net/wireless/intel/iwlwifi/mvm/debugfs-vif.c
> index 2453ceabf00d..6925527d8457 100644
> --- 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 iwl_mvm *mvm, struct ieee80211_vif *vif)
> 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;
>

\
 
 \ /
  Last update: 2019-04-01 17:39    [W:0.056 / U:3.972 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site