From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794060864; b=uqdlBi8HGYzKp1Llzy+6BnA6LNnpLVE+hu0JMNfHTB8ukKHuPrpQx2jfQyGvGg42w52Q ty+12m1r54LPjtVQ3gAsHPuALGJSyg57CaVcG9tCo+xn9bKBSujq6RNVQjg2U4Kvjj546 0m5cWy+slIPcdXLD1Gozy+hAoAoNzjaapiPG+U11gIg/PJ+qxaOxp3WIC+CCQRGVLUH5K g/lSkXTu4ej2MInsHmv08Co5Q8GhCF0fX/m/Gx1SRPSqQ85oY3Z9/AsqW4mNs+UNh0mzS Voox/9TvvbAg06aGG58jG/Ftg5EzPNuvuWEiekjH3/+FMEoty23o5lhU4c0Ffhwiiwg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794060864; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=QKx613dasEPvth/LkrRrgAX/SZPKUgMh3IRB808pXns=; b=aAhwm8TgDRu9sPJ1ddu4nLXw0JieVwkYptf2fR1OnLULmDF3nCki9aOWa/gF96iuIwdB jR7HhpAL7Q8IQ7kyiaQXYY/I/XH3Qu44XJih2F1sv9TKBW3VmNbU+tR8om4rBVgood7kC qf3pDcBK1wMFBn7JzInTiGF0wn0rfo8F/MnKSZae6UeC1pbe6twKDQdC28BZCE6nmqRgL BUeYywgwpl/PHF6W3z40gxscXnlwXjKyPe2eTye+CXkiMmClxcCWzJ7f9eptQyF0c9Cyg p++DPVQkdijLioGtJrqYMq6rYp4P8N31HmvhdhIosnyVRcl38IAT1ki57pwxJHtAilQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=e+Kqd4k+; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 78751606A338; Sat, 7 Nov 2026 14:14:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=e+Kqd4k+ Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1148A1F0089F; Sat, 7 Nov 2026 14:14:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794060864; bh=QKx613dasEPvth/LkrRrgAX/SZPKUgMh3IRB808pXns=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=e+Kqd4k+akscBj5nEFKeioVoBCG9hUae3fAYSlTu90XhFr0EmfmaLUuxY2rkgjm2Y og8uJaKVcK5+YP2W5bw0vr/fuusjYKVYEKGQ5hF3mkfvAQvKMIsNxR+R9GNpcRaSCp yDde4I3EVe/Xyu0rNJJVjOPdYVGCTtYuSuyCyz9o= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Prashant Rahul , Felix Fietkau , Sasha Levin Subject: [PATCH 6.12 0245/1536] wifi: mt76: mt7921: fix memory leak when skb_linearize fails in mcu rx event Date: Sat, 7 Nov 2026 08:37:41 -0500 Message-ID: <20261107135004.562760261@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134957.653319350@linuxfoundation.org> References: <20261107134957.653319350@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Prashant Rahul [ Upstream commit 4361f1660101270611eb5dc39799f620b35f2e4d ] The ownership of sk_buff skb is passed to mt7921_queue_rx_skb, each path inside it under the switch case handles cleaning of skb and it is true for mt7921_mcu_rx_event as well. mt7921_mcu_rx_event, on a success path, either queues skb via mt76_mcu_rx_event or cleans it immediately inside mt7921_mcu_uni_rx_unsolicited_event. However inside mt7921_mcu_rx_event, if skb_linearize fails, the function returns immediately and never bothers cleaning skb which leaks skb. Since skb is fully owned at this point, it is safe to call dev_kfree_skb which fixes the leak. Granted, the skb_linearize failure is rare as it can only fail under heavy memory usage, but at the same time, leaking memory under heavy memory usage can worsen the OOM condition. Signed-off-by: Prashant Rahul Link: https://patch.msgid.link/20260716-mt7921-mem-leak-v1-1-6e9c0ea19f63@gmail.com Signed-off-by: Felix Fietkau Signed-off-by: Sasha Levin --- drivers/net/wireless/mediatek/mt76/mt7921/mcu.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7921/mcu.c index 6caf8fbd6a7f2..bc7a99b58ba48 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7921/mcu.c +++ b/drivers/net/wireless/mediatek/mt76/mt7921/mcu.c @@ -348,8 +348,10 @@ void mt7921_mcu_rx_event(struct mt792x_dev *dev, struct sk_buff *skb) { struct mt76_connac2_mcu_rxd *rxd; - if (skb_linearize(skb)) + if (skb_linearize(skb)) { + dev_kfree_skb(skb); return; + } rxd = (struct mt76_connac2_mcu_rxd *)skb->data; -- 2.53.0