From patchwork Sun Jun 23 09:06:43 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Edward Adam Davis X-Patchwork-Id: 13708545 Received: from out162-62-58-216.mail.qq.com (out162-62-58-216.mail.qq.com [162.62.58.216]) (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 5BCBB1C14; Sun, 23 Jun 2024 09:11:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=162.62.58.216 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719133920; cv=none; b=LvQxAE+50SHXcBmfLQj0cTsSL1kPujYk9I0YoPEa/InCtlymmK3jAntiZ67murg1fQoS+5WG3k1B6Xta8bJEE4dlVFYwaJcPT3Daw3mQb3lwBNc5eMcMjz8k+a8S+3v7c1Y21jLqeeAew8ap+J4F3kNoNWGDr94bGgHePdxy9Ss= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719133920; c=relaxed/simple; bh=9PpbKR6w3Iu2ALPSmk5bOIP7zdMirW30x7ODlfnmSI8=; h=Message-ID:From:To:Cc:Subject:Date:In-Reply-To:References: MIME-Version; b=tE4traCK2z8c2FCsJc8DSS7gJ1Xdb6ywbtC5ZCDZBJmYb30FPvWe6glI80gZYfLVHY4b6q6E0r6on4QR5yLX34bAblGENyqEFKk6tG14Bg3ss0TTwJuAUwrvug/jTxMpqRxUsodqU61FQX3tj8dftS1fvuyOSo9yHltPtEXsteo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=qq.com; spf=pass smtp.mailfrom=qq.com; dkim=pass (1024-bit key) header.d=qq.com header.i=@qq.com header.b=XMoYSk8i; arc=none smtp.client-ip=162.62.58.216 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=qq.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=qq.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=qq.com header.i=@qq.com header.b="XMoYSk8i" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qq.com; s=s201512; t=1719133605; bh=F2Y5FsltYYu6RBm0fojOKhVSeGmbWVg+5v1x+DrOyMY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=XMoYSk8iu3/RNxcMdfNBfFRB1kwcXEPY4lAmYbF4VVJ3sAUZYayfJchXF6Dzx/DTH 0qK8W1b0Av2QMRIH9jJMz0NS3MFclj5yqN1GiGp4YcXA4LLfEQILFv8PWBWk9I4w1P rMxA/OgG5PB59Aa9UT6/z6JFwZQblBxjhc4rM4fI= Received: from pek-lxu-l1.wrs.com ([111.198.228.103]) by newxmesmtplogicsvrsza29-0.qq.com (NewEsmtp) with SMTP id 1AA9C83B; Sun, 23 Jun 2024 17:06:42 +0800 X-QQ-mid: xmsmtpt1719133602t9vru0epp Message-ID: X-QQ-XMAILINFO: OQhZ3T0tjf0aplMQ3N6eZX3MWPmIvMrZA1q+KMlXuKsOZwU/nFV7zxH6hgAzxw 3vPyeYKRQYf0CEzPOfkpQAtDS2+1WQQN8tw5+OUZb5sQBDBOuA3oLWoIfgnciNXm5zlxAeFJKmu+ 0gP+bpEYfbE81+9BY4Z7kP65yj1ehRiK9o0a13/V4MVCa9oKWcdMSE45uJ+5bGZYJ0elnskSAkZW d3I3wVN3VMUWTKQDCnqZZTfrHV+yADfYgQhd3NBDY1wpwRzGBonZFHlMN7Qokw04Ie2xdJUDnLxg GB90md7/x7tplrRnnqs2ycuECMjL5N9HBNrE3lWhGd59mvKNIc9FXojbQFgm1IY2b/5AQLpIJjHe l0DdXD+TaYUXXsBAjbG1y9Ob1JaGNNiwu8Vzm0uwfP0P8EwUurxesKfXr1kNy8LkCD5Po8QXkNyO L/9Aor7uo5BibW6sCIF2Dw7xLyrGwdvcV0GQjst+b3x5+ExhQtsYFzS6NzNFg5pHU18in4h7z+4v xq8CPmR2hIVv/DBTOMCTyLax6zGDVIHfcCnaMLq5wPjty9RrW/83m1xrYG8hU3AEYPt5NGmzqedg JPpNEqbhGiaO0UOBNYg0PV9XlccMaqnOyaOpdBiX4eGBsvAZV0bQohL2vI6TeX7gfsGUSnSQ40kX CjCc3YRWkIFJmhdqQbI6zdPyLJb7ENhM9tvTLCQC0xGnOMy00dTh9busVBIJLC72uJiAA+9W0K9J wKwJ/kNuX0HAjHJDnNERxKnAnz4U69YiXuCya+Mc90Ay9zB6fM+HcWS1w58b6PQ2hK2tWMq3kt4j mijuL5zq7V5h11YNrsm+mzt6Z89z7SXfsVm39keKNVvmYnhKrlLiFmd7nGmIL/jzp6seLAfTdF7p FquJYffUZpKrxImja3wy7CD21gIpJ1lgpeRDaDFRUjjGGU/DqXwXedvVkYvdiXCpeGflZcsjWK X-QQ-XMRINFO: NyFYKkN4Ny6FSmKK/uo/jdU= From: Edward Adam Davis To: syzbot+35ebc808442df6420eae@syzkaller.appspotmail.com Cc: johan.hedberg@gmail.com, linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org, luiz.dentz@gmail.com, marcel@holtmann.org, syzkaller-bugs@googlegroups.com Subject: [PATCH] Bluetooth: fix double free in hci_req_sync_complete Date: Sun, 23 Jun 2024 17:06:43 +0800 X-OQ-MSGID: <20240623090642.3753697-2-eadavis@qq.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <00000000000033a6e8061b3c6d4a@google.com> References: <00000000000033a6e8061b3c6d4a@google.com> Precedence: bulk X-Mailing-List: linux-bluetooth@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Look at the following situation: cpu1 cpu2 ==== ==== sock_ioctl sock_do_ioctl hci_sock_ioctl hci_rx_work hci_dev_cmd hci_event_packet hci_req_sync req_complete_skb __hci_req_sync hci_req_sync_complete If hci_rx_work executes before __hci_req_sync releases req_skb, everything is normal, otherwise it will result in double free of req_skb. Adding NULL check of req_skb before releasing it can avoid double free. Fixes: 45d355a926ab ("Bluetooth: Fix memory leak in hci_req_sync_complete()") Reported-and-tested-by: syzbot+35ebc808442df6420eae@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=35ebc808442df6420eae Signed-off-by: Edward Adam Davis --- net/bluetooth/hci_request.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c index efea25eb56ce..3862fa6bb288 100644 --- a/net/bluetooth/hci_request.c +++ b/net/bluetooth/hci_request.c @@ -106,7 +106,8 @@ void hci_req_sync_complete(struct hci_dev *hdev, u8 result, u16 opcode, hdev->req_result = result; hdev->req_status = HCI_REQ_DONE; if (skb) { - kfree_skb(hdev->req_skb); + if (hdev->req_skb) + kfree_skb(hdev->req_skb); hdev->req_skb = skb_get(skb); } wake_up_interruptible(&hdev->req_wait_q);