4.14-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 1222a16014888ed9733c11e221730d4a8196222b ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- net/wireless/nl80211.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-)
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 5e7c9b361e8a..46e9812d13c0 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -9720,7 +9720,7 @@ 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? */ @@ -9757,10 +9757,19 @@ 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); }