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 323CE2EA494; Tue, 15 Jul 2025 13:48:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752587313; cv=none; b=E/MsS9cTLSL3C8F+BkbWKYUAsoTLeqLGsZ4oSIeOf+C24vAcEPya6MY6H/AnhCPlxmDC7V+OpOPytqTpFKW4RPvlaGoZ8NAHeYNOYMwao+U8rpD4FuHA+i4UUuZgZhDiZMcEt9HVVg/iZswh5YwyIY8cQ8GEkdakZQeQV3sgrhQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752587313; c=relaxed/simple; bh=mk8Oy78nE9uJZOi39ajZVtnrz8uk0yk/2wgTC/FqQZQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=r0gX4WRdKv4eu6EvtoPYvl69wQzyelhVgAbnjcjsMAvJ7uLzE3pMnlRRcUmxhgmtg0IPltdo6g1798ZOK+GpwIJ6PbE/UXzL1Nb8yDXAr3d2aA83ZDSDU+sTnp3ePBFnftsuyOKy5n5HLxtDhTLInmlE1AZl+8ptZXk8QDea2UA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ePq0Oii0; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ePq0Oii0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B3C92C4CEF1; Tue, 15 Jul 2025 13:48:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1752587313; bh=mk8Oy78nE9uJZOi39ajZVtnrz8uk0yk/2wgTC/FqQZQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ePq0Oii0tIE4zzryeJcoOP8recbJy7P2YyKnJ1Fi3ENh9SXDKM6b0S5olIFk6DDTj tBVIVDK8yEhr5FrnQO8X8iDzvXjvq7YIxyfiihTw4l35qwzP1yH09fkj84BOHdFYOh CiK0lK1DnOmGqj0UWyGZ0c/7yUtKq1zfjQqAL7OY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Daniil Dulov , Johannes Berg , Sasha Levin Subject: [PATCH 6.1 54/88] wifi: zd1211rw: Fix potential NULL pointer dereference in zd_mac_tx_to_dev() Date: Tue, 15 Jul 2025 15:14:30 +0200 Message-ID: <20250715130756.727814453@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250715130754.497128560@linuxfoundation.org> References: <20250715130754.497128560@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Daniil Dulov [ Upstream commit 74b1ec9f5d627d2bdd5e5b6f3f81c23317657023 ] There is a potential NULL pointer dereference in zd_mac_tx_to_dev(). For example, the following is possible: T0 T1 zd_mac_tx_to_dev() /* len == skb_queue_len(q) */ while (len > ZD_MAC_MAX_ACK_WAITERS) { filter_ack() spin_lock_irqsave(&q->lock, flags); /* position == skb_queue_len(q) */ for (i=1; itype == NL80211_IFTYPE_AP) skb = __skb_dequeue(q); spin_unlock_irqrestore(&q->lock, flags); skb_dequeue() -> NULL Since there is a small gap between checking skb queue length and skb being unconditionally dequeued in zd_mac_tx_to_dev(), skb_dequeue() can return NULL. Then the pointer is passed to zd_mac_tx_status() where it is dereferenced. In order to avoid potential NULL pointer dereference due to situations like above, check if skb is not NULL before passing it to zd_mac_tx_status(). Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 459c51ad6e1f ("zd1211rw: port to mac80211") Signed-off-by: Daniil Dulov Link: https://patch.msgid.link/20250626114619.172631-1-d.dulov@aladdin.ru Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin --- drivers/net/wireless/zydas/zd1211rw/zd_mac.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/zydas/zd1211rw/zd_mac.c b/drivers/net/wireless/zydas/zd1211rw/zd_mac.c index 80b905d499542..57269c317ce22 100644 --- a/drivers/net/wireless/zydas/zd1211rw/zd_mac.c +++ b/drivers/net/wireless/zydas/zd1211rw/zd_mac.c @@ -583,7 +583,11 @@ void zd_mac_tx_to_dev(struct sk_buff *skb, int error) skb_queue_tail(q, skb); while (skb_queue_len(q) > ZD_MAC_MAX_ACK_WAITERS) { - zd_mac_tx_status(hw, skb_dequeue(q), + skb = skb_dequeue(q); + if (!skb) + break; + + zd_mac_tx_status(hw, skb, mac->ack_pending ? mac->ack_signal : 0, NULL); mac->ack_pending = 0; -- 2.39.5