4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ping-Ke Shih pkshih@realtek.com
[ 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@realtek.com Signed-off-by: Ping-Ke Shih pkshih@realtek.com Link: https://lore.kernel.org/r/20230203023636.4418-1-pkshih@realtek.com Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/mac80211/cfg.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c index 94293b57f1b23..05e74004376fb 100644 --- a/net/mac80211/cfg.c +++ b/net/mac80211/cfg.c @@ -2428,6 +2428,10 @@ 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; }