Vincent reports: > The ath5k driver seems to do an array-index-out-of-bounds access as > shown by the UBSAN kernel message: > UBSAN: array-index-out-of-bounds in > drivers/net/wireless/ath/ath5k/base.c:1741:20 > index 4 is out of range for type 'ieee80211_tx_rate [4]' > ... > Call Trace: > <TASK> > dump_stack_lvl+0x5d/0x80 > ubsan_epilogue+0x5/0x2b > __ubsan_handle_out_of_bounds.cold+0x46/0x4b > ath5k_tasklet_tx+0x4e0/0x560 [ath5k] > tasklet_action_common+0xb5/0x1c0
It is real. 'ts->ts_final_idx' can be 3 on 5212, so: info->status.rates[ts->ts_final_idx + 1].idx = -1; with the array defined as: struct ieee80211_tx_rate rates[IEEE80211_TX_MAX_RATES]; while the size is: #define IEEE80211_TX_MAX_RATES 4 is indeed bogus. Set this 'idx = -1' sentinel only if the array index is less than the array size. As mac80211 will not look at rates beyond the size (IEEE80211_TX_MAX_RATES). Note: The effect of the OOB write is negligible. It just overwrites the next member of info->status, i.e. ack_signal. Signed-off-by: Jiri Slaby (SUSE) <[email protected]> Reported-by: Vincent Danjean <[email protected]> Link: https://lore.kernel.org/all/[email protected] Closes: https://bugs.debian.org/1119093 Fixes: 6d7b97b23e11 ("ath5k: fix tx status reporting issues") Cc: [email protected] --- [v2] added Fixes + Cc: stable Cc: [email protected] Cc: Salvatore Bonaccorso <[email protected]> Cc: Nick Kossifidis <[email protected]>, Cc: Luis Chamberlain <[email protected]> Cc: [email protected] --- drivers/net/wireless/ath/ath5k/base.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/ath/ath5k/base.c b/drivers/net/wireless/ath/ath5k/base.c index 4d88b02ffa79..917e1b087924 100644 --- a/drivers/net/wireless/ath/ath5k/base.c +++ b/drivers/net/wireless/ath/ath5k/base.c @@ -1738,7 +1738,8 @@ ath5k_tx_frame_completed(struct ath5k_hw *ah, struct sk_buff *skb, } info->status.rates[ts->ts_final_idx].count = ts->ts_final_retry; - info->status.rates[ts->ts_final_idx + 1].idx = -1; + if (ts->ts_final_idx + 1 < IEEE80211_TX_MAX_RATES) + info->status.rates[ts->ts_final_idx + 1].idx = -1; if (unlikely(ts->ts_status)) { ah->stats.ack_fail++; -- 2.52.0
