diff options
authorBrian Norris <briannorris@chromium.org>2017-06-29 18:23:54 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-09-13 14:09:45 -0700
commit4a9c294d7b1e7cf965e4b2e2e9955b9b548a1a0b (patch)
parent926374f5e66914f7b835eaa0f2c71144dc33e974 (diff)
mwifiex: correct channel stat buffer overflows
commit 4b5dde2d6234ff5bc68e97e6901d1f2a0a7f3749 upstream. mwifiex records information about various channels as it receives scan information. It does this by appending to a buffer that was sized to the max number of supported channels on any band, but there are numerous problems: (a) scans can return info from more than one band (e.g., both 2.4 and 5 GHz), so the determined "max" is not large enough (b) some firmware appears to return multiple results for a given channel, so the max *really* isn't large enough (c) there is no bounds checking when stashing these stats, so problems (a) and (b) can easily lead to buffer overflows Let's patch this by setting a slightly-more-correct max (that accounts for a combination of both 2.4G and 5G bands) and adding a bounds check when writing to our statistics buffer. Due to problem (b), we still might not properly report all known survey information (e.g., with "iw <dev> survey dump"), since duplicate results (or otherwise "larger than expected" results) will cause some truncation. But that's a problem for a future bugfix. (And because of this known deficiency, only log the excess at the WARN level, since that isn't visible by default in this driver and would otherwise be a bit too noisy.) Fixes: bf35443314ac ("mwifiex: channel statistics support for mwifiex") Cc: Avinash Patil <patila@marvell.com> Cc: Xinming Hu <huxm@marvell.com> Signed-off-by: Brian Norris <briannorris@chromium.org> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Reviewed-by: Ganapathi Bhat <gbhat@marvell.com> Signed-off-by: Kalle Valo <kvalo@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2 files changed, 7 insertions, 1 deletions
diff --git a/drivers/net/wireless/mwifiex/cfg80211.c b/drivers/net/wireless/mwifiex/cfg80211.c
index c3331d6201c3..9a8982f581c5 100644
--- a/drivers/net/wireless/mwifiex/cfg80211.c
+++ b/drivers/net/wireless/mwifiex/cfg80211.c
@@ -3740,7 +3740,7 @@ int mwifiex_init_channel_scan_gap(struct mwifiex_adapter *adapter)
if (adapter->config_bands & BAND_A)
n_channels_a = mwifiex_band_5ghz.n_channels;
- adapter->num_in_chan_stats = max_t(u32, n_channels_bg, n_channels_a);
+ adapter->num_in_chan_stats = n_channels_bg + n_channels_a;
adapter->chan_stats = vmalloc(sizeof(*adapter->chan_stats) *
diff --git a/drivers/net/wireless/mwifiex/scan.c b/drivers/net/wireless/mwifiex/scan.c
index c20017ced566..fb98f42cb5e7 100644
--- a/drivers/net/wireless/mwifiex/scan.c
+++ b/drivers/net/wireless/mwifiex/scan.c
@@ -2170,6 +2170,12 @@ mwifiex_update_chan_statistics(struct mwifiex_private *priv,
sizeof(struct mwifiex_chan_stats);
for (i = 0 ; i < num_chan; i++) {
+ if (adapter->survey_idx >= adapter->num_in_chan_stats) {
+ mwifiex_dbg(adapter, WARN,
+ "FW reported too many channel results (max %d)\n",
+ adapter->num_in_chan_stats);
+ return;
+ }
chan_stats.chan_num = fw_chan_stats->chan_num;
chan_stats.bandcfg = fw_chan_stats->bandcfg;
chan_stats.flags = fw_chan_stats->flags;