This is a note to let you know that I've just added the patch titled
wifi: mac80211: don't return unset power in ieee80211_get_tx_power()
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
wifi-mac80211-don-t-return-unset-power-in-ieee80211_.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit f259db92245d883cc06072d4bb0d79d74b786ea2
Author: Ping-Ke Shih <pkshih@xxxxxxxxxxx>
Date: Fri Feb 3 10:36:36 2023 +0800
wifi: mac80211: don't return unset power in ieee80211_get_tx_power()
[ Upstream commit e160ab85166e77347d0cbe5149045cb25e83937f ]
We can get a UBSAN warning if ieee80211_get_tx_power() returns the
INT_MIN value mac80211 internally uses for "unset power level".
UBSAN: signed-integer-overflow in net/wireless/nl80211.c:3816:5
-2147483648 * 100 cannot be represented in type 'int'
CPU: 0 PID: 20433 Comm: insmod Tainted: G WC OE
Call Trace:
dump_stack+0x74/0x92
ubsan_epilogue+0x9/0x50
handle_overflow+0x8d/0xd0
__ubsan_handle_mul_overflow+0xe/0x10
nl80211_send_iface+0x688/0x6b0 [cfg80211]
[...]
cfg80211_register_wdev+0x78/0xb0 [cfg80211]
cfg80211_netdev_notifier_call+0x200/0x620 [cfg80211]
[...]
ieee80211_if_add+0x60e/0x8f0 [mac80211]
ieee80211_register_hw+0xda5/0x1170 [mac80211]
In this case, simply return an error instead, to indicate
that no data is available.
Cc: Zong-Zhe Yang <kevin_yang@xxxxxxxxxxx>
Signed-off-by: Ping-Ke Shih <pkshih@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230203023636.4418-1-pkshih@xxxxxxxxxxx
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 5659af1bec179..77d8ed184c1c4 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -2452,6 +2452,10 @@ static int ieee80211_get_tx_power(struct wiphy *wiphy,
else
*dbm = sdata->vif.bss_conf.txpower;
+ /* INT_MIN indicates no power level was set yet */
+ if (*dbm == INT_MIN)
+ return -EINVAL;
+
return 0;
}
