6.17-stable review patch. If anyone has any objections, please let me know.
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From: Dan Carpenter dan.carpenter@linaro.org
[ Upstream commit 77e67d5daaf155f7d0f99f4e797c4842169ec19e ]
This code frees "link" by calling kfree_rcu(link, rcu_head) and then it dereferences "link" to get the "link->fw_id". Save the "link->fw_id" first to avoid a potential use after free.
Fixes: d1e879ec600f ("wifi: iwlwifi: add iwlmld sub-driver") Signed-off-by: Dan Carpenter dan.carpenter@linaro.org Link: https://patch.msgid.link/aNKCcKlbSkkS4_gO@stanley.mountain Signed-off-by: Miri Korenblit miriam.rachel.korenblit@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wireless/intel/iwlwifi/mld/link.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/intel/iwlwifi/mld/link.c b/drivers/net/wireless/intel/iwlwifi/mld/link.c index 782fc41aa1c31..960dcd208f005 100644 --- a/drivers/net/wireless/intel/iwlwifi/mld/link.c +++ b/drivers/net/wireless/intel/iwlwifi/mld/link.c @@ -501,6 +501,7 @@ void iwl_mld_remove_link(struct iwl_mld *mld, struct iwl_mld_vif *mld_vif = iwl_mld_vif_from_mac80211(bss_conf->vif); struct iwl_mld_link *link = iwl_mld_link_from_mac80211(bss_conf); bool is_deflink = link == &mld_vif->deflink; + u8 fw_id = link->fw_id;
if (WARN_ON(!link || link->active)) return; @@ -513,10 +514,10 @@ void iwl_mld_remove_link(struct iwl_mld *mld,
RCU_INIT_POINTER(mld_vif->link[bss_conf->link_id], NULL);
- if (WARN_ON(link->fw_id >= mld->fw->ucode_capa.num_links)) + if (WARN_ON(fw_id >= mld->fw->ucode_capa.num_links)) return;
- RCU_INIT_POINTER(mld->fw_id_to_bss_conf[link->fw_id], NULL); + RCU_INIT_POINTER(mld->fw_id_to_bss_conf[fw_id], NULL); }
void iwl_mld_handle_missed_beacon_notif(struct iwl_mld *mld,