[PATCH 5.15 360/917] mac80211: twt: dont use potentially unaligned pointer

Greg Kroah-Hartman
2021-11-15T23:37:47Z

From: Johannes Berg <johannes.berg@intel.com>

[ Upstream commit 7ff379ba2d4b7b205240e666601fe302207d73f8 ]

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 <lkp@intel.com>
Fixes: f5a4c24e689f ("mac80211: introduce individual TWT support in AP mode")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20210927115124.e1208694f37b.Ie3de9bcc5dde5a79e3ac81f3185beafe4d214e57@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/mac80211/s1g.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/net/mac80211/s1g.c b/net/mac80211/s1g.c
index 7e35ab5b61664..4141bc80cdfd6 100644
--- a/net/mac80211/s1g.c
+++ b/net/mac80211/s1g.c
@@ -104,9 +104,11 @@ 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->req_type |=
+ le16_encode_bits(TWT_SETUP_CMD_REJECT,
+ IEEE80211_TWT_REQTYPE_SETUP_CMD);
goto out;
}

--
2.33.0