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author | Brian Norris <briannorris@chromium.org> | 2017-06-30 01:23:54 (GMT) |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-09-09 15:39:40 (GMT) |
commit | 0e720cd70631968e506e13fa366da77d4cf770e1 (patch) | |
tree | ea5b10ac4edac256c14cd332b91fad58d43d2442 | |
parent | 5c23d3ed1190eb91ebb208d2fb8414b92b566a37 (diff) | |
download | linux-0e720cd70631968e506e13fa366da77d4cf770e1.tar.xz |
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>
-rw-r--r-- | drivers/net/wireless/marvell/mwifiex/cfg80211.c | 2 | ||||
-rw-r--r-- | drivers/net/wireless/marvell/mwifiex/scan.c | 6 |
2 files changed, 7 insertions, 1 deletions
diff --git a/drivers/net/wireless/marvell/mwifiex/cfg80211.c b/drivers/net/wireless/marvell/mwifiex/cfg80211.c index afdbbf5..8677a53 100644 --- a/drivers/net/wireless/marvell/mwifiex/cfg80211.c +++ b/drivers/net/wireless/marvell/mwifiex/cfg80211.c @@ -4188,7 +4188,7 @@ 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) * adapter->num_in_chan_stats); diff --git a/drivers/net/wireless/marvell/mwifiex/scan.c b/drivers/net/wireless/marvell/mwifiex/scan.c index 97c9765..78d59a6 100644 --- a/drivers/net/wireless/marvell/mwifiex/scan.c +++ b/drivers/net/wireless/marvell/mwifiex/scan.c @@ -2479,6 +2479,12 @@ 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; |