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 8A73239734B; Fri, 15 May 2026 16:24:13 +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=1778862253; cv=none; b=ZnMXQIGT+1jzVmQMqzLUhWlaLKbQ2LnYB+juWoNVmrlC1zpQWLnSDvrBRcLSmSdPiO/xR2Pc+TSbobxGQ+nvHh7cd7kzRWdv9WO4Vkj6qJMD6TJE3FqWQHV43ESjXhjvLLVYwlCVoUuqmhvH1TiMLQkg8gPTSAKe62sudbjalvs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778862253; c=relaxed/simple; bh=AKUCLvlLGby2rI+ddhOn9+G3uxooUPIPwTzdNHg+DHs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=i5tF8VdRMyVpAQ/ayQRY4f4nCDLYQKyQFIC6IBiy160pzJIuUnc+pdIk8byVSTzWpkj2ALyant8ek9nCPOR9L0rXAA7HVnS8CKC0kIx2qrHbFXno8MrorlDzIJcC+8OrrFbARmBI4fToZHoOshCTmSZgKL7g8LzUksSoL83OyoA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=QtVdAUBI; 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="QtVdAUBI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EC82EC2BCB0; Fri, 15 May 2026 16:24:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1778862253; bh=AKUCLvlLGby2rI+ddhOn9+G3uxooUPIPwTzdNHg+DHs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QtVdAUBIxVitEe1a6w8nu49o/rJPrxYczrEzrh2Za0vRRUQ2CHBQwBmKnHMAoDXSQ w00NPjWsYAODZWqh5mot6ODy2rbXc6YHmwkJu1kqBPZ9TDz5Ime2mTWz4t2l5vdvdt mNH1zsn1mDQ7u7vKprH+ndTP1k+LXbF31arAMqiY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Luiz Augusto von Dentz , David Carlier , Sasha Levin Subject: [PATCH 6.18 168/188] Bluetooth: hci_conn: fix potential UAF in create_big_sync Date: Fri, 15 May 2026 17:49:45 +0200 Message-ID: <20260515154700.980212081@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260515154657.309489048@linuxfoundation.org> References: <20260515154657.309489048@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Carlier [ Upstream commit 0beddb0c380bed5f5b8e61ddbe14635bb73d0b41 ] Add hci_conn_valid() check in create_big_sync() to detect stale connections before proceeding with BIG creation. Handle the resulting -ECANCELED in create_big_complete() and re-validate the connection under hci_dev_lock() before dereferencing, matching the pattern used by create_le_conn_complete() and create_pa_complete(). Keep the hci_conn object alive across the async boundary by taking a reference via hci_conn_get() when queueing create_big_sync(), and dropping it in the completion callback. The refcount and the lock are complementary: the refcount keeps the object allocated, while hci_dev_lock() serializes hci_conn_hash_del()'s list_del_rcu() on hdev->conn_hash, as required by hci_conn_del(). hci_conn_put() is called outside hci_dev_unlock() so the final put (which resolves to kfree() via bt_link_release) does not run under hdev->lock, though the release path would be safe either way. Without this, create_big_complete() would unconditionally dereference the conn pointer on error, causing a use-after-free via hci_connect_cfm() and hci_conn_del(). Fixes: eca0ae4aea66 ("Bluetooth: Add initial implementation of BIS connections") Cc: stable@vger.kernel.org Co-developed-by: Luiz Augusto von Dentz Signed-off-by: Luiz Augusto von Dentz Signed-off-by: David Carlier Signed-off-by: Luiz Augusto von Dentz [ kept stable's `qos->bcast.out.phy == 0x02` context line instead of upstream's renamed `qos->bcast.out.phys == BIT(1)` ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/bluetooth/hci_conn.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) --- a/net/bluetooth/hci_conn.c +++ b/net/bluetooth/hci_conn.c @@ -2113,6 +2113,9 @@ static int create_big_sync(struct hci_de u32 flags = 0; int err; + if (!hci_conn_valid(hdev, conn)) + return -ECANCELED; + if (qos->bcast.out.phy == 0x02) flags |= MGMT_ADV_FLAG_SEC_2M; @@ -2188,11 +2191,24 @@ static void create_big_complete(struct h bt_dev_dbg(hdev, "conn %p", conn); + if (err == -ECANCELED) + goto done; + + hci_dev_lock(hdev); + + if (!hci_conn_valid(hdev, conn)) + goto unlock; + if (err) { bt_dev_err(hdev, "Unable to create BIG: %d", err); hci_connect_cfm(conn, err); hci_conn_del(conn); } + +unlock: + hci_dev_unlock(hdev); +done: + hci_conn_put(conn); } struct hci_conn *hci_bind_bis(struct hci_dev *hdev, bdaddr_t *dst, __u8 sid, @@ -2309,10 +2325,11 @@ struct hci_conn *hci_connect_bis(struct BT_BOUND, &data); /* Queue start periodic advertising and create BIG */ - err = hci_cmd_sync_queue(hdev, create_big_sync, conn, + err = hci_cmd_sync_queue(hdev, create_big_sync, hci_conn_get(conn), create_big_complete); if (err < 0) { hci_conn_drop(conn); + hci_conn_put(conn); return ERR_PTR(err); }