On Fri, Feb 27, 2009 at 12:32:55AM +0100, Jiri Slaby wrote: > On 27.2.2009 00:28, Bob Copeland wrote: >> hw_to_driver_rix() returns sc->rate_idx[x][y] as an int, and that >> array is initialized to (u8)-1 for invalid rates. So, it can >> return 255 if the hardware rate index (y) is bad, then the check >> "rxs.rate_idx>= 0" would always be true, right? If it's not a >> real bug yet, it likely will be one day :) > > Ah, yes, it really is a bug(tm), care to post a fix?
Actually, I remembered in the dark recesses of my moldering brain that someone had a lost patch for this a while ago, so I searched the archives. Pavel, ok to add your s-o-b? From: Pavel Roskin <[email protected]> Subject: [PATCH] ath5k: use signed elements for rate index table A lookup table is used to convert from hardware rate indexes back to driver-based rate indexes. For unknown hardware rates, we initialize these values to -1, but since the array elements are of type u8, they will be in the range 0-255. This can cause array overruns because subsequent sanity checks only check for negative values. Signed-off-by: Bob Copeland <[email protected]> --- drivers/net/wireless/ath5k/base.h | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/net/wireless/ath5k/base.h b/drivers/net/wireless/ath5k/base.h index 20e0d14..8229561 100644 --- a/drivers/net/wireless/ath5k/base.h +++ b/drivers/net/wireless/ath5k/base.h @@ -112,7 +112,7 @@ struct ath5k_softc { struct ieee80211_supported_band sbands[IEEE80211_NUM_BANDS]; struct ieee80211_channel channels[ATH_CHAN_MAX]; struct ieee80211_rate rates[IEEE80211_NUM_BANDS][AR5K_MAX_RATES]; - u8 rate_idx[IEEE80211_NUM_BANDS][AR5K_MAX_RATES]; + s8 rate_idx[IEEE80211_NUM_BANDS][AR5K_MAX_RATES]; enum nl80211_iftype opmode; struct ath5k_hw *ah; /* Atheros HW */ -- 1.5.4.1 -- Bob Copeland %% www.bobcopeland.com _______________________________________________ ath5k-devel mailing list [email protected] https://lists.ath5k.org/mailman/listinfo/ath5k-devel
