diff options
| author | Kees Cook <keescook@chromium.org> | 2021-11-18 12:38:39 -0800 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2021-11-26 11:54:03 +0100 |
| commit | fb5f6a0e8063b7a84d6d44ef353846ccd7708d2e (patch) | |
| tree | 80855ee79eca1dbf02442ae112e37ce3b3924867 | |
| parent | eb87d3e08992b2939d91b649630dfa11f4d2cd75 (diff) | |
| download | linux-fb5f6a0e8063b7a84d6d44ef353846ccd7708d2e.tar.bz2 | |
mac80211: Use memset_after() to clear tx status
In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.
Use memset_after() so memset() doesn't get confused about writing
beyond the destination member that is intended to be the starting point
of zeroing through the end of the struct.
Additionally fix the common helper, ieee80211_tx_info_clear_status(),
which was not clearing ack_signal, but the open-coded versions
did. Johannes Berg points out this bug was introduced by commit
e3e1a0bcb3f1 ("mac80211: reduce IEEE80211_TX_MAX_RATES") but was harmless.
Also drops the associated unneeded BUILD_BUG_ON()s, and adds a note to
carl9170 about usage.
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Christian Lamparter <chunkeey@gmail.com> [both CARL9170+P54USB on real HW]
Link: https://lore.kernel.org/r/20211118203839.1289276-1-keescook@chromium.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
| -rw-r--r-- | drivers/net/wireless/ath/carl9170/tx.c | 12 | ||||
| -rw-r--r-- | drivers/net/wireless/intersil/p54/txrx.c | 6 | ||||
| -rw-r--r-- | include/net/mac80211.h | 7 |
3 files changed, 8 insertions, 17 deletions
diff --git a/drivers/net/wireless/ath/carl9170/tx.c b/drivers/net/wireless/ath/carl9170/tx.c index 88444fe6d1c6..1b76f4434c06 100644 --- a/drivers/net/wireless/ath/carl9170/tx.c +++ b/drivers/net/wireless/ath/carl9170/tx.c @@ -275,12 +275,12 @@ static void carl9170_tx_release(struct kref *ref) if (WARN_ON_ONCE(!ar)) return; - BUILD_BUG_ON( - offsetof(struct ieee80211_tx_info, status.ack_signal) != 20); - - memset(&txinfo->status.ack_signal, 0, - sizeof(struct ieee80211_tx_info) - - offsetof(struct ieee80211_tx_info, status.ack_signal)); + /* + * This does not call ieee80211_tx_info_clear_status() because + * carl9170_tx_fill_rateinfo() has filled the rate information + * before we get to this point. + */ + memset_after(&txinfo->status, 0, rates); if (atomic_read(&ar->tx_total_queued)) ar->tx_schedule = true; diff --git a/drivers/net/wireless/intersil/p54/txrx.c b/drivers/net/wireless/intersil/p54/txrx.c index 873fea59894f..8414aa208655 100644 --- a/drivers/net/wireless/intersil/p54/txrx.c +++ b/drivers/net/wireless/intersil/p54/txrx.c @@ -431,11 +431,7 @@ static void p54_rx_frame_sent(struct p54_common *priv, struct sk_buff *skb) * Clear manually, ieee80211_tx_info_clear_status would * clear the counts too and we need them. */ - memset(&info->status.ack_signal, 0, - sizeof(struct ieee80211_tx_info) - - offsetof(struct ieee80211_tx_info, status.ack_signal)); - BUILD_BUG_ON(offsetof(struct ieee80211_tx_info, - status.ack_signal) != 20); + memset_after(&info->status, 0, rates); if (entry_hdr->flags & cpu_to_le16(P54_HDR_FLAG_DATA_ALIGN)) pad = entry_data->align[0]; diff --git a/include/net/mac80211.h b/include/net/mac80211.h index 10e6fe215f0f..e349f57d19ae 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -1205,12 +1205,7 @@ ieee80211_tx_info_clear_status(struct ieee80211_tx_info *info) /* clear the rate counts */ for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) info->status.rates[i].count = 0; - - BUILD_BUG_ON( - offsetof(struct ieee80211_tx_info, status.ack_signal) != 20); - memset(&info->status.ampdu_ack_len, 0, - sizeof(struct ieee80211_tx_info) - - offsetof(struct ieee80211_tx_info, status.ampdu_ack_len)); + memset_after(&info->status, 0, rates); } |