mac80211: pending brcmfmac patches cleaning channels management

They prepare brcmfmac for using wiphy_read_of_freq_limits.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>

1 files changed, 100 insertions, 0 deletions

diff --git a/package/kernel/mac80211/patches/840-brcmfmac-avoid-writing-channel-out-of-allocated-arra.patch b/package/kernel/mac80211/patches/840-brcmfmac-avoid-writing-channel-out-of-allocated-arra.patch
new file mode 100644
index 0000000000..8456a1364c
--- /dev/null
+++ b/package/kernel/mac80211/patches/840-brcmfmac-avoid-writing-channel-out-of-allocated-arra.patch
@@ -0,0 +1,100 @@
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
+Date: Wed, 4 Jan 2017 12:09:41 +0100
+Subject: [PATCH] brcmfmac: avoid writing channel out of allocated array
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Our code was assigning number of channels to the index variable by
+default. If firmware reported channel we didn't predict this would
+result in using that initial index value and writing out of array. This
+never happened so far (we got a complete list of supported channels) but
+it means possible memory corruption so we should handle it anyway.
+
+This patch simply detects unexpected channel and ignores it.
+
+As we don't try to create new entry now, it's also safe to drop hw_value
+and center_freq assignment. For known channels we have these set anyway.
+
+I decided to fix this issue by assigning NULL or a target channel to the
+channel variable. This was one of possible ways, I prefefred this one as
+it also avoids using channel[index] over and over.
+
+Fixes: 58de92d2f95e ("brcmfmac: use static superset of channels for wiphy bands")
+Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
+Acked-by: Arend van Spriel <arend.vanspriel@broadcom.com>
+---
+
+--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
++++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
+@@ -5913,7 +5913,6 @@ static int brcmf_construct_chaninfo(stru
+ 	u32 i, j;
+ 	u32 total;
+ 	u32 chaninfo;
+-	u32 index;
+ 
+ 	pbuf = kzalloc(BRCMF_DCMD_MEDLEN, GFP_KERNEL);
+ 
+@@ -5961,33 +5960,36 @@ static int brcmf_construct_chaninfo(stru
+ 		    ch.bw == BRCMU_CHAN_BW_80)
+ 			continue;
+ 
+-		channel = band->channels;
+-		index = band->n_channels;
++		channel = NULL;
+ 		for (j = 0; j < band->n_channels; j++) {
+-			if (channel[j].hw_value == ch.control_ch_num) {
+-				index = j;
++			if (band->channels[j].hw_value == ch.control_ch_num) {
++				channel = &band->channels[j];
+ 				break;
+ 			}
+ 		}
+-		channel[index].center_freq =
+-			ieee80211_channel_to_frequency(ch.control_ch_num,
+-						       band->band);
+-		channel[index].hw_value = ch.control_ch_num;
++		if (!channel) {
++			/* It seems firmware supports some channel we never
++			 * considered. Something new in IEEE standard?
++			 */
++			brcmf_err("Ignoring unexpected firmware channel %d\n",
++				  ch.control_ch_num);
++			continue;
++		}
+ 
+ 		/* assuming the chanspecs order is HT20,
+ 		 * HT40 upper, HT40 lower, and VHT80.
+ 		 */
+ 		if (ch.bw == BRCMU_CHAN_BW_80) {
+-			channel[index].flags &= ~IEEE80211_CHAN_NO_80MHZ;
++			channel->flags &= ~IEEE80211_CHAN_NO_80MHZ;
+ 		} else if (ch.bw == BRCMU_CHAN_BW_40) {
+-			brcmf_update_bw40_channel_flag(&channel[index], &ch);
++			brcmf_update_bw40_channel_flag(channel, &ch);
+ 		} else {
+ 			/* enable the channel and disable other bandwidths
+ 			 * for now as mentioned order assure they are enabled
+ 			 * for subsequent chanspecs.
+ 			 */
+-			channel[index].flags = IEEE80211_CHAN_NO_HT40 |
+-					       IEEE80211_CHAN_NO_80MHZ;
++			channel->flags = IEEE80211_CHAN_NO_HT40 |
++					 IEEE80211_CHAN_NO_80MHZ;
+ 			ch.bw = BRCMU_CHAN_BW_20;
+ 			cfg->d11inf.encchspec(&ch);
+ 			chaninfo = ch.chspec;
+@@ -5995,11 +5997,11 @@ static int brcmf_construct_chaninfo(stru
+ 						       &chaninfo);
+ 			if (!err) {
+ 				if (chaninfo & WL_CHAN_RADAR)
+-					channel[index].flags |=
++					channel->flags |=
+ 						(IEEE80211_CHAN_RADAR |
+ 						 IEEE80211_CHAN_NO_IR);
+ 				if (chaninfo & WL_CHAN_PASSIVE)
+-					channel[index].flags |=
++					channel->flags |=
+ 						IEEE80211_CHAN_NO_IR;
+ 			}
+ 		}