| Message ID | f7c17a7f-f173-43bf-bc39-316b8adde349@stanley.mountain (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Johannes Berg |
| Headers | show |
| Series | [next] wifi: iwlwifi: Fix uninitialized variable with __free() | expand |
| Context | Check | Description |
|---|---|---|
| wifibot/tree_selection | success | Guessing tree name failed - patch did not apply |
> -----Original Message----- > From: Dan Carpenter <dan.carpenter@linaro.org> > Sent: Wednesday, 12 March 2025 10:32 > To: Korenblit, Miriam Rachel <miriam.rachel.korenblit@intel.com> > Cc: Berg, Johannes <johannes.berg@intel.com>; Anjaneyulu, Pagadala Yesu > <pagadala.yesu.anjaneyulu@intel.com>; Grumbach, Emmanuel > <emmanuel.grumbach@intel.com>; Stern, Avraham > <avraham.stern@intel.com>; Ben Shimol, Yedidya > <yedidya.ben.shimol@intel.com>; Gabay, Daniel <daniel.gabay@intel.com>; > linux-wireless@vger.kernel.org; linux-kernel@vger.kernel.org; kernel- > janitors@vger.kernel.org > Subject: [PATCH next] wifi: iwlwifi: Fix uninitialized variable with __free() > > Pointers declared with the __free(kfree) attribute need to be initialized because > they will be passed to kfree() on every return path. There are two return > statement before the "cmd" pointer is initialized so this leads to an uninitialized > variable bug. > > Fixes: d1e879ec600f ("wifi: iwlwifi: add iwlmld sub-driver") > Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> > --- > drivers/net/wireless/intel/iwlwifi/mld/debugfs.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/wireless/intel/iwlwifi/mld/debugfs.c > b/drivers/net/wireless/intel/iwlwifi/mld/debugfs.c > index c759c5c68dc0..1d4b2ad5d388 100644 > --- a/drivers/net/wireless/intel/iwlwifi/mld/debugfs.c > +++ b/drivers/net/wireless/intel/iwlwifi/mld/debugfs.c > @@ -556,8 +556,8 @@ iwl_dbgfs_vif_twt_setup_write(struct iwl_mld *mld, char > *buf, size_t count, > }; > struct ieee80211_vif *vif = data; > struct iwl_mld_vif *mld_vif = iwl_mld_vif_from_mac80211(vif); > + struct iwl_dhc_cmd *cmd __free(kfree) = NULL; > struct iwl_dhc_twt_operation *dhc_twt_cmd; > - struct iwl_dhc_cmd *cmd __free(kfree); > u64 target_wake_time; > u32 twt_operation, interval_exp, interval_mantissa, min_wake_duration; > u8 trigger, flow_type, flow_id, protection, tenth_param; > -- > 2.47.2 Acked-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
On 3/12/2025 1:31 AM, Dan Carpenter wrote: > Pointers declared with the __free(kfree) attribute need to be initialized > because they will be passed to kfree() on every return path. There are > two return statement before the "cmd" pointer is initialized so this > leads to an uninitialized variable bug. > > Fixes: d1e879ec600f ("wifi: iwlwifi: add iwlmld sub-driver") > Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> > --- > drivers/net/wireless/intel/iwlwifi/mld/debugfs.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/wireless/intel/iwlwifi/mld/debugfs.c b/drivers/net/wireless/intel/iwlwifi/mld/debugfs.c > index c759c5c68dc0..1d4b2ad5d388 100644 > --- a/drivers/net/wireless/intel/iwlwifi/mld/debugfs.c > +++ b/drivers/net/wireless/intel/iwlwifi/mld/debugfs.c > @@ -556,8 +556,8 @@ iwl_dbgfs_vif_twt_setup_write(struct iwl_mld *mld, char *buf, size_t count, > }; > struct ieee80211_vif *vif = data; > struct iwl_mld_vif *mld_vif = iwl_mld_vif_from_mac80211(vif); > + struct iwl_dhc_cmd *cmd __free(kfree) = NULL; hmm, I thought the recommended convention was to define __free() pointers at the point of allocation. cleanup.h explicitly says: * Given that the "__free(...) = NULL" pattern for variables defined at * the top of the function poses this potential interdependency problem * the recommendation is to always define and assign variables in one * statement and not group variable definitions at the top of the * function when __free() is used. > struct iwl_dhc_twt_operation *dhc_twt_cmd; > - struct iwl_dhc_cmd *cmd __free(kfree); > u64 target_wake_time; > u32 twt_operation, interval_exp, interval_mantissa, min_wake_duration; > u8 trigger, flow_type, flow_id, protection, tenth_param;
On Wed, Mar 12, 2025 at 08:15:18AM -0700, Jeff Johnson wrote: > On 3/12/2025 1:31 AM, Dan Carpenter wrote: > > Pointers declared with the __free(kfree) attribute need to be initialized > > because they will be passed to kfree() on every return path. There are > > two return statement before the "cmd" pointer is initialized so this > > leads to an uninitialized variable bug. > > > > Fixes: d1e879ec600f ("wifi: iwlwifi: add iwlmld sub-driver") > > Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> > > --- > > drivers/net/wireless/intel/iwlwifi/mld/debugfs.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/net/wireless/intel/iwlwifi/mld/debugfs.c b/drivers/net/wireless/intel/iwlwifi/mld/debugfs.c > > index c759c5c68dc0..1d4b2ad5d388 100644 > > --- a/drivers/net/wireless/intel/iwlwifi/mld/debugfs.c > > +++ b/drivers/net/wireless/intel/iwlwifi/mld/debugfs.c > > @@ -556,8 +556,8 @@ iwl_dbgfs_vif_twt_setup_write(struct iwl_mld *mld, char *buf, size_t count, > > }; > > struct ieee80211_vif *vif = data; > > struct iwl_mld_vif *mld_vif = iwl_mld_vif_from_mac80211(vif); > > + struct iwl_dhc_cmd *cmd __free(kfree) = NULL; > > hmm, I thought the recommended convention was to define __free() pointers at > the point of allocation. cleanup.h explicitly says: > > * Given that the "__free(...) = NULL" pattern for variables defined at > * the top of the function poses this potential interdependency problem > * the recommendation is to always define and assign variables in one > * statement and not group variable definitions at the top of the > * function when __free() is used. > People do it either way. I'm agnostic so long as it doesn't have bugs. regards, dan carpenter
… > +++ b/drivers/net/wireless/intel/iwlwifi/mld/debugfs.c > @@ -556,8 +556,8 @@ iwl_dbgfs_vif_twt_setup_write(struct iwl_mld *mld, char *buf, size_t count, > }; > struct ieee80211_vif *vif = data; > struct iwl_mld_vif *mld_vif = iwl_mld_vif_from_mac80211(vif); > + struct iwl_dhc_cmd *cmd __free(kfree) = NULL; > struct iwl_dhc_twt_operation *dhc_twt_cmd; > - struct iwl_dhc_cmd *cmd __free(kfree); … Can it be recommended to reduce the scope for the affected local variable instead? https://elixir.bootlin.com/linux/v6.14-rc6/source/include/linux/cleanup.h#L129-L133 Regards, Markus
diff --git a/drivers/net/wireless/intel/iwlwifi/mld/debugfs.c b/drivers/net/wireless/intel/iwlwifi/mld/debugfs.c index c759c5c68dc0..1d4b2ad5d388 100644 --- a/drivers/net/wireless/intel/iwlwifi/mld/debugfs.c +++ b/drivers/net/wireless/intel/iwlwifi/mld/debugfs.c @@ -556,8 +556,8 @@ iwl_dbgfs_vif_twt_setup_write(struct iwl_mld *mld, char *buf, size_t count, }; struct ieee80211_vif *vif = data; struct iwl_mld_vif *mld_vif = iwl_mld_vif_from_mac80211(vif); + struct iwl_dhc_cmd *cmd __free(kfree) = NULL; struct iwl_dhc_twt_operation *dhc_twt_cmd; - struct iwl_dhc_cmd *cmd __free(kfree); u64 target_wake_time; u32 twt_operation, interval_exp, interval_mantissa, min_wake_duration; u8 trigger, flow_type, flow_id, protection, tenth_param;
Pointers declared with the __free(kfree) attribute need to be initialized because they will be passed to kfree() on every return path. There are two return statement before the "cmd" pointer is initialized so this leads to an uninitialized variable bug. Fixes: d1e879ec600f ("wifi: iwlwifi: add iwlmld sub-driver") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> --- drivers/net/wireless/intel/iwlwifi/mld/debugfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)