From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 84BF12E3FE for ; Tue, 7 Nov 2023 12:13:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="RG5PdjNY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E43A0C433C9; Tue, 7 Nov 2023 12:13:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699359220; bh=QH+7x9v85OUtiMkQxRToOchKcwdfsEMANuA873gHQI8=; h=From:To:Cc:Subject:Date:From; b=RG5PdjNYtrFF1T10gJ9QUAY8P/fBq50PWs/VrnvpUUz6s0zGQ5KuYoHVdOLHZlPbN xliS72fJQ6+zBl7l8PnvsbGHA6qMohw0zVen+K4bogLNaAL7ANJ/3tcWOQGIEO+SiX wwzjCRrOhBSzpolhHyCBXrDp+9eTf+8r2XA9N4GDKTWSJ2BHg3GdKheXmISpQ0guYc 4j+Lq1ztAXU3R9Ru806W4KTPMDC2e5YhQ69qpEdT+oz1JoQJENVlzqYkN5YNypcz1N 6q7xBC7+NSYdsgQ7oA6+7pFQOYLVawnOTfvE4W6ZJSaEd6lLXEyjjvR3pGui63tPkG zIyXxZO5nt7UQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ping-Ke Shih , Zong-Zhe Yang , Johannes Berg , Sasha Levin , johannes@sipsolutions.net, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, linux-wireless@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 1/4] wifi: mac80211: don't return unset power in ieee80211_get_tx_power() Date: Tue, 7 Nov 2023 07:13:31 -0500 Message-ID: <20231107121337.3759240-1-sashal@kernel.org> X-Mailer: git-send-email 2.42.0 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 4.14.328 Content-Transfer-Encoding: 8bit From: Ping-Ke Shih [ 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 Signed-off-by: Ping-Ke Shih Link: https://lore.kernel.org/r/20230203023636.4418-1-pkshih@realtek.com Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin --- 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; } -- 2.42.0