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[8/9] iwlwifi: mvm: debugfs: check length precisely in inject_packet

Message ID iwlwifi.20210117164916.5184dfc2a445.I0631d2e4f6ffb93cf06618edb035c45bd6d1d7b9@changeid
State Accepted
Commit 5c255a10711b139877044164b5822ef4e8811c7c
Delegated to: Luca Coelho
Headers show
Series iwlwifi: updates intended for v5.12 2021-01-17 part 2 | expand

Commit Message

Luca Coelho Jan. 17, 2021, 2:52 p.m. UTC
From: Johannes Berg <johannes.berg@intel.com>

When we check the length, we only check that the advertised
data length fits into the data we have, but currently not
that it actually matches correctly.

This should be harmless, but if the first two bytes are zero,
then the iwl_rx_packet_payload_len() ends up negative, and
that might later cause issues if unsigned variables are used,
as this is not something that's normally expected.

Change the validation here to precisely validate the lengths
match, to avoid such issues.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
 drivers/net/wireless/intel/iwlwifi/mvm/debugfs.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox series


diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/debugfs.c b/drivers/net/wireless/intel/iwlwifi/mvm/debugfs.c
index 231c3489cc31..3834d7197e11 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/debugfs.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/debugfs.c
@@ -1169,9 +1169,9 @@  static ssize_t iwl_dbgfs_inject_packet_write(struct iwl_mvm *mvm,
 	if (ret)
 		goto out;
-	/* avoid invalid memory access */
+	/* avoid invalid memory access and malformed packet */
 	if (bin_len < sizeof(*pkt) ||
-	    bin_len < sizeof(*pkt) + iwl_rx_packet_payload_len(pkt))
+	    bin_len != sizeof(*pkt) + iwl_rx_packet_payload_len(pkt))
 		goto out;