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| author |   Masashi Honma <masashi.honma@gmail.com> | 2018-09-25 11:15:01 +0900 |
|---|---|---|
| committer |   Johannes Berg <johannes.berg@intel.com> | 2018-09-27 11:44:44 +0200 |
| commit | 1222a16014888ed9733c11e221730d4a8196222b (patch) | |
| tree | 996fc5f62a229ad0d726fa868eecf21cc4ff7ba9 /net | |
| parent | mac80211_hwsim: do not omit multicast announce of first added radio (diff) | |
| download | linux-dev-1222a16014888ed9733c11e221730d4a8196222b.tar.xz linux-dev-1222a16014888ed9733c11e221730d4a8196222b.zip | |
nl80211: Fix possible Spectre-v1 for CQM RSSI thresholds
Use array_index_nospec() to sanitize i with respect to speculation.
Note that the user doesn't control i directly, but can make it out
of bounds by not finding a threshold in the array.
Signed-off-by: Masashi Honma <masashi.honma@gmail.com>
[add note about user control, as explained by Masashi]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net')
| -rw-r--r-- | net/wireless/nl80211.c | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index bd26230de63e..176edfefcbaa 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -10231,7 +10231,7 @@ static int cfg80211_cqm_rssi_update(struct cfg80211_registered_device *rdev, struct wireless_dev *wdev = dev->ieee80211_ptr; s32 last, low, high; u32 hyst; - int i, n; + int i, n, low_index; int err; /* RSSI reporting disabled? */ @@ -10268,10 +10268,19 @@ static int cfg80211_cqm_rssi_update(struct cfg80211_registered_device *rdev, if (last < wdev->cqm_config->rssi_thresholds[i]) break; - low = i > 0 ? - (wdev->cqm_config->rssi_thresholds[i - 1] - hyst) : S32_MIN; - high = i < n ? - (wdev->cqm_config->rssi_thresholds[i] + hyst - 1) : S32_MAX; + low_index = i - 1; + if (low_index >= 0) { + low_index = array_index_nospec(low_index, n); + low = wdev->cqm_config->rssi_thresholds[low_index] - hyst; + } else { + low = S32_MIN; + } + if (i < n) { + i = array_index_nospec(i, n); + high = wdev->cqm_config->rssi_thresholds[i] + hyst - 1; + } else { + high = S32_MAX; + } return rdev_set_cqm_rssi_range_config(rdev, dev, low, high); } |