Messages in this thread |  | | Subject | Re: [PATCH] iwlwifi: properly check debugfs dentry before using it | From | Laura Abbott <> | Date | Mon, 1 Apr 2019 08:39:26 -0700 |
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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; >
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