FAILED: patch "[PATCH] wifi: iwlwifi: mvm: fix 6 GHz scan construction" failed to apply to 6.6-stable tree

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 7245012f0f496162dd95d888ed2ceb5a35170f1a
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2024110521-antler-uneatable-d873@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 7245012f0f496162dd95d888ed2ceb5a35170f1a Mon Sep 17 00:00:00 2001
From: Johannes Berg <[email protected]>
Date: Wed, 23 Oct 2024 09:17:44 +0200
Subject: [PATCH] wifi: iwlwifi: mvm: fix 6 GHz scan construction

If more than 255 colocated APs exist for the set of all APs found during 2.4/5 GHz scanning, then the 6 GHz scan construction will loop forever since the loop variable has type u8, which can never reach the number found when that's bigger than 255, and is stored in a u32 variable. Also move it into the loops to have a smaller scope.

Using a u32 there is fine, we limit the number of APs in the scan list and each has a limit on the number of RNR entries due to the frame size. With a limit of 1000 scan results, a frame size upper bound of 4096 (really it's more like ~2300) and a TBTT entry size of at least 11, we get an upper bound for the number of ~372k, well in the bounds of a u32.

index 3ce9150213a7..ddcbd80a49fb 100644
@@ -1774,7 +1774,7 @@ iwl_mvm_umac_scan_cfg_channels_v7_6g(struct iwl_mvm *mvm,
 			&cp->channel_config[ch_cnt];
 
 		u32 s_ssid_bitmap = 0, bssid_bitmap = 0, flags = 0;
-		u8 j, k, n_s_ssids = 0, n_bssids = 0;
+		u8 k, n_s_ssids = 0, n_bssids = 0;
 		u8 max_s_ssids, max_bssids;
 		bool force_passive = false, found = false, allow_passive = true,
 		     unsolicited_probe_on_chan = false, psc_no_listen = false;

@@ -1799,7 +1799,7 @@ iwl_mvm_umac_scan_cfg_channels_v7_6g(struct iwl_mvm *mvm,
 		cfg->v5.iter_count = 1;
 		cfg->v5.iter_interval = 0;
 
-		for (j = 0; j < params->n_6ghz_params; j++) {
+		for (u32 j = 0; j < params->n_6ghz_params; j++) {
 			s8 tmp_psd_20;
 
 			if (!(scan_6ghz_params[j].channel_idx == i))

@@ -1873,7 +1873,7 @@ iwl_mvm_umac_scan_cfg_channels_v7_6g(struct iwl_mvm *mvm,
 		 * SSID.
 		 * TODO: improve this logic
 		 */
-		for (j = 0; j < params->n_6ghz_params; j++) {
+		for (u32 j = 0; j < params->n_6ghz_params; j++) {
 			if (!(scan_6ghz_params[j].channel_idx == i))
 				continue;
 

From: Johannes Berg <[email protected]>

Upstream commit 7245012f0f496162dd95d888ed2ceb5a35170f1a.

If more than 255 colocated APs exist for the set of all APs found during 2.4/5 GHz scanning, then the 6 GHz scan construction will loop forever since the loop variable has type u8, which can never reach the number found when that's bigger than 255, and is stored in a u32 variable. Also move it into the loops to have a smaller scope.

Using a u32 there is fine, we limit the number of APs in the scan list and each has a limit on the number of RNR entries due to the frame size. With a limit of 1000 scan results, a frame size upper bound of 4096 (really it's more like ~2300) and a TBTT entry size of at least 11, we get an upper bound for the number of ~372k, well in the bounds of a u32.

---
 drivers/net/wireless/intel/iwlwifi/mvm/scan.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

index aa6ef6491205..16818dcdae22 100644
@@ -1753,7 +1753,8 @@ iwl_mvm_umac_scan_cfg_channels_v6_6g(struct iwl_mvm_scan_params *params,
 			&cp->channel_config[i];
 
 		u32 s_ssid_bitmap = 0, bssid_bitmap = 0, flags = 0;
-		u8 j, k, s_max = 0, b_max = 0, n_used_bssid_entries;
+		u8 k, s_max = 0, b_max = 0, n_used_bssid_entries;
+		u32 j;
 		bool force_passive, found = false, allow_passive = true,
 		     unsolicited_probe_on_chan = false, psc_no_listen = false;
 

2.47.0