The patch below does not apply to the v5.15-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 stable@vger.kernel.org.

Thanks, Sasha

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

From 7245012f0f496162dd95d888ed2ceb5a35170f1a Mon Sep 17 00:00:00 2001 From: Johannes Berg johannes.berg@intel.com 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.

Cc: stable@vger.kernel.org Fixes: eae94cf82d74 ("iwlwifi: mvm: add support for 6GHz") Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219375 Link: https://patch.msgid.link/20241023091744.f4baed5c08a1.I8b417148bbc8c5d11c101e... Signed-off-by: Johannes Berg johannes.berg@intel.com --- drivers/net/wireless/intel/iwlwifi/mvm/scan.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/scan.c b/drivers/net/wireless/intel/iwlwifi/mvm/scan.c index 3ce9150213a74..ddcbd80a49fb2 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/scan.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/scan.c @@ -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;