2021-09-27 09:54:43

by Johannes Berg

[permalink] [raw]
Subject: [PATCH] mac80211: twt: don't use potentially unaligned pointer

From: Johannes Berg <[email protected]>

Since we're pointing into a frame, the pointer to the
twt_agrt->req_type struct member is potentially not
aligned properly. Open-code le16p_replace_bits() to
avoid passing an unaligned pointer.

Reported-by: kernel test robot <[email protected]>
Fixes: f5a4c24e689f ("mac80211: introduce individual TWT support in AP mode")
Signed-off-by: Johannes Berg <[email protected]>
---
net/mac80211/s1g.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/net/mac80211/s1g.c b/net/mac80211/s1g.c
index 7e35ab5b6166..01140dd42a8b 100644
--- a/net/mac80211/s1g.c
+++ b/net/mac80211/s1g.c
@@ -104,9 +104,10 @@ ieee80211_s1g_rx_twt_setup(struct ieee80211_sub_if_data *sdata,

/* broadcast TWT not supported yet */
if (twt->control & IEEE80211_TWT_CONTROL_NEG_TYPE_BROADCAST) {
- le16p_replace_bits(&twt_agrt->req_type,
- TWT_SETUP_CMD_REJECT,
- IEEE80211_TWT_REQTYPE_SETUP_CMD);
+ twt_agrt->req_type &=
+ ~cpu_to_le16(IEEE80211_TWT_REQTYPE_SETUP_CMD);
+ twt_agrt |= le16_encode_bits(TWT_SETUP_CMD_REJECT,
+ IEEE80211_TWT_REQTYPE_SETUP_CMD);
goto out;
}

--
2.31.1