Please ignore this. It was by mistake when I was checking my git-send-email.. -----Original Message----- From: Ghorai, Sukumar Sent: Thursday, July 13, 2017 4:45 AM To: Murthy, Shanth <shanth.murthy@xxxxxxxxx> Cc: Brian Norris <briannorris@xxxxxxxxxxxx>; stable@xxxxxxxxxxxxxxx; Avinash Patil <patila@xxxxxxxxxxx>; Xinming Hu <huxm@xxxxxxxxxxx> Subject: [PATCH 2/2] FROMLIST: mwifiex: correct channel stat buffer overflows From: Brian Norris <briannorris@xxxxxxxxxxxx> 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: <stable@xxxxxxxxxxxxxxx> Cc: Avinash Patil <patila@xxxxxxxxxxx> Cc: Xinming Hu <huxm@xxxxxxxxxxx> Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx> (am from https://patchwork.kernel.org/patch/9818269/) BUG=b:63081833 TEST=kevin Wifi; verify that survey results don't overflow Change-Id: Ic0c7b56c7852dcacf055a3003c26789fae794680 Reviewed-on: https://chromium-review.googlesource.com/557351 Commit-Ready: Brian Norris <briannorris@xxxxxxxxxxxx> Tested-by: Brian Norris <briannorris@xxxxxxxxxxxx> Reviewed-by: Brian Norris <briannorris@xxxxxxxxxxxx> --- drivers/net/wireless/marvell/mwifiex/cfg80211.c | 2 +- drivers/net/wireless/marvell/mwifiex/scan.c | 6 ++++++ 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/marvell/mwifiex/cfg80211.c b/drivers/net/wireless/marvell/mwifiex/cfg80211.c index 99947e8c0a7d..ac29d6a0b591 100644 --- a/drivers/net/wireless/marvell/mwifiex/cfg80211.c +++ b/drivers/net/wireless/marvell/mwifiex/cfg80211.c @@ -4206,7 +4206,7 @@ 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 708346e9109a..78317dc9d719 100644 --- a/drivers/net/wireless/marvell/mwifiex/scan.c +++ b/drivers/net/wireless/marvell/mwifiex/scan.c @@ -2480,6 +2480,12 @@ 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; -- 2.7.4