[SRU][M][PATCH 1/1] wifi: iwlwifi: fix double-free bug

[Bethany Jamison]

From: Johannes Berg <johannes.berg at intel.com>

commit 353d321f63f7dbfc9ef58498cc732c9fe886a596 upstream.

The storage for the TLV PC register data wasn't done like all
the other storage in the drv->fw area, which is cleared at the
end of deallocation. Therefore, the freeing must also be done
differently, explicitly NULL'ing it out after the free, since
otherwise there's a nasty double-free bug here if a file fails
to load after this has been parsed, and we get another free
later (e.g. because no other file exists.) Fix that by adding
the missing NULL assignment.

Cc: stable at vger.kernel.org
Fixes: 5e31b3df86ec ("wifi: iwlwifi: dbg: print pc register data once fw dump occurred")
Reported-by: Guy Kaplan <guy.kaplan at intel.com>
Signed-off-by: Johannes Berg <johannes.berg at intel.com>
Reviewed-by: Gregory Greenman <gregory.greenman at intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit at intel.com>
Link: https://msgid.link/20240123200528.675f3c24ec0d.I6ab4015cd78d82dd95471f840629972ef0331de3@changeid
Signed-off-by: Johannes Berg <johannes.berg at intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
(cherry picked from commit d24eb9a27bea8fe5237fa71be274391d9d51eff2 linux-6.7.y)
CVE-2024-26694
Signed-off-by: Bethany Jamison <bethany.jamison at canonical.com>
---
 drivers/net/wireless/intel/iwlwifi/iwl-drv.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-drv.c b/drivers/net/wireless/intel/iwlwifi/iwl-drv.c
index fb5e254757e71..8faf4e7872bb9 100644
--- a/drivers/net/wireless/intel/iwlwifi/iwl-drv.c
+++ b/drivers/net/wireless/intel/iwlwifi/iwl-drv.c
@@ -128,6 +128,7 @@ static void iwl_dealloc_ucode(struct iwl_drv *drv)
 	kfree(drv->fw.ucode_capa.cmd_versions);
 	kfree(drv->fw.phy_integration_ver);
 	kfree(drv->trans->dbg.pc_data);
+	drv->trans->dbg.pc_data = NULL;
 
 	for (i = 0; i < IWL_UCODE_TYPE_MAX; i++)
 		iwl_free_fw_img(drv, drv->fw.img + i);
-- 
2.34.1