[PATCH 5.15 487/917] iwlwifi: pnvm: dont kmemdup() more than we have

[Greg Kroah-Hartman]

From: Johannes Berg <johannes.berg@xxxxxxxxx>

[ Upstream commit 0f892441d8c353144e3669b7991fa5fe0bd353e9 ]

We shouldn't kmemdup() more data than we have, that might
cause the code to crash. Fix that by updating the length
before the kmemdup.

Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Luca Coelho <luciano.coelho@xxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/iwlwifi.20211016114029.ab0e64c3fba9.Ic6a3295fc384750b51b4270bf0b7d94984a139f2@changeid
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/wireless/intel/iwlwifi/fw/pnvm.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/fw/pnvm.c b/drivers/net/wireless/intel/iwlwifi/fw/pnvm.c
index dde22bdc87039..9b0eee53488ab 100644
--- a/drivers/net/wireless/intel/iwlwifi/fw/pnvm.c
+++ b/drivers/net/wireless/intel/iwlwifi/fw/pnvm.c
@@ -284,16 +284,15 @@ int iwl_pnvm_load(struct iwl_trans *trans,
 	/* First attempt to get the PNVM from BIOS */
 	package = iwl_uefi_get_pnvm(trans, &len);
 	if (!IS_ERR_OR_NULL(package)) {
+		/* we need only the data */
+		len -= sizeof(*package);
 		data = kmemdup(package->data, len, GFP_KERNEL);
 
 		/* free package regardless of whether kmemdup succeeded */
 		kfree(package);
 
-		if (data) {
-			/* we need only the data size */
-			len -= sizeof(*package);
+		if (data)
 			goto parse;
-		}
 	}
 
 	/* If it's not available, try from the filesystem */
-- 
2.33.0