From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f198.google.com (mail-pf1-f198.google.com [209.85.210.198]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CB818499F03 for ; Thu, 6 Aug 2026 22:10:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.198 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786054252; cv=none; b=u0UyMygtfOY0dirdLP/gRyguiekYcCU/zFMz7I3OZH7tR2HRAwVeS87VLWsSZrDJCqFaNAufbnrLsBTjKUazIcBD2jXh+xK/PIh1E5DlZ3kbGabo0HjBtD0jooADQ4ZYipwdG1yliWAYdhzWyfo+zDpOf+IPSk4rvFWaxZzbQ/0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786054252; c=relaxed/simple; bh=+o9QGjIip+mB0zT5m8VqWQBgDa+DKcbyBA/hKPuZl1s=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=HB7jXcC+B7KwZX6jA/I31ssBS2CNRcQq+4692+FoYec2WZiqaUYifn8dO8FXnVgAxrzjHQOnkt8eW/MnsGd6eeEz1V6RuJsyrmlPu+k6H55KwSpr9hwyi5JC/oML06Lp5mSXo7IXBt+PbFGf/lpy6LIOEhrwBoyDw3QLQIkiEEY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--tkjos.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=qTN+4bkx; arc=none smtp.client-ip=209.85.210.198 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--tkjos.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="qTN+4bkx" Received: by mail-pf1-f198.google.com with SMTP id d2e1a72fcca58-84870e7f498so2905468b3a.3 for ; Thu, 06 Aug 2026 15:10:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1786054250; x=1786659050; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:mime-version:date:from :to:cc:subject:date:message-id:reply-to:content-type; bh=vP2d7oDvPp3Hc8fnAHJj8Oo/Gn81Eu0dp5TtGDR52bc=; b=qTN+4bkxb18QYW0Fpbhrd23SrEuAF0EiyykAT622oEJT5AjQFKcacUTWxM8JzPfNyI 6pMcpd1lYCwVGz+wZM9CHpriQikM6HbzKq5I9HZQTBoy8fiDLXMCG8zV66/fhZxsnpq/ Tg/Q1+tiuYHdFPaxaSPq8qSGIySdOlbv2VIV/1ru1xgwiP0hWwMzDcxno5MarULPTnIZ k9gPqWn3Q3vYrJkz2ED81DPwRxfcuTi4zwWZ/6Fhtze0R0aIkZxP3T2ZrR9SVS4CL5xt IE0qPBpOMUlA6ndGjbN8XbVnn4/tmpe/XGYDUVad17byW6apAVJbaO5gXGoNjmOuz4PH YASQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786054250; x=1786659050; h=content-type:cc:to:from:subject:message-id:mime-version:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=vP2d7oDvPp3Hc8fnAHJj8Oo/Gn81Eu0dp5TtGDR52bc=; b=Ik9U1sfcnAcZ/AXbxcYi17wLX2tkkZ/2yXkv5E/2XqzD4DEsDwq6Tk+SbUNS+Bj5uf BmZyjMZ5SKvLfII0Kh5jZlnyJ15T6tuUx7MiOT1VcKNofMBuSaO0tIPc8tZX5ofmsz6L 9i9rnJIKC2npbg7a26KAVoIO02OLn5pl9Or0IleT+ER+c4u4Ghzbv6blMgQLz9R29vus FlnSjXAGI7KxZDe1b1A7SN8D5VWCFqrOPdSFkQr+8iRB5TNTbyzw+K+8wxbtWr/NSycX 5JqDX2RbmT6tDevM1GClVF9B9Xj13nLcIJM8d6CDz/p6WkWynlx+NFna+RIb97yWU1ZR EnEg== X-Gm-Message-State: AOJu0YxzpcLpRMsg0RTNMSatgrz3/FkESsw4FgMAYqjnUmANWMJExfVc auBVk9iCn/jsd3g1ejnxw9jvqu2gek+QM+7BYu11rv1XPU1LSWCt4+/9UGttozE68pm8cB/Bi7S 7O8r97smoNuk3AGpHDoWyjhY0t0Inz4ju7lRYxq9nIxFoPc68/4QX3Ux0VamxIW2dDRSH/66BDZ Yq35UeyLB6bQVghflN1ZEAT1todJvLUM4= X-Received: from pgbcn6.prod.google.com ([2002:a05:6a02:a86:b0:ca5:80e2:129c]) (user=tkjos job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:1886:b0:847:99a7:c751 with SMTP id d2e1a72fcca58-84f2e05d02dmr17681622b3a.25.1786054249492; Thu, 06 Aug 2026 15:10:49 -0700 (PDT) Date: Thu, 6 Aug 2026 22:10:44 +0000 Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.55.0.654.g21b8a5bc05-goog Message-ID: <20260806221044.1169839-1-tkjos@google.com> Subject: [PATCH] Bluetooth: hci_conn: fix potential UAF in create_big_sync From: Todd Kjos To: stable@vger.kernel.org Cc: kernel-team@android.com, Lee Jones , Greg Kroah-Hartman , Luiz Augusto von Dentz , Sasha Levin , David Carlier , Todd Kjos Content-Type: text/plain; charset="UTF-8" [ 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 [ Backported to 6.1.y: included inline helper hci_conn_valid() in include/net/bluetooth/hci_core.h from upstream commit 881559af5f5c ] Signed-off-by: Todd Kjos --- include/net/bluetooth/hci_core.h | 18 ++++++++++++++++++ net/bluetooth/hci_conn.c | 19 ++++++++++++++++++- 2 files changed, 36 insertions(+), 1 deletion(-) diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h index e67b1e5e0d2c8fb3c49696dd73e5fd6753412155..76764d399b23eff885e307148391c9cba5c6a4d0 100644 --- a/include/net/bluetooth/hci_core.h +++ b/include/net/bluetooth/hci_core.h @@ -1069,6 +1069,24 @@ static inline unsigned int hci_conn_count(struct hci_dev *hdev) return c->acl_num + c->amp_num + c->sco_num + c->le_num + c->iso_num; } +static inline bool hci_conn_valid(struct hci_dev *hdev, struct hci_conn *conn) +{ + struct hci_conn_hash *h = &hdev->conn_hash; + struct hci_conn *c; + + rcu_read_lock(); + + list_for_each_entry_rcu(c, &h->list, list) { + if (c == conn) { + rcu_read_unlock(); + return true; + } + } + rcu_read_unlock(); + + return false; +} + static inline __u8 hci_conn_lookup_type(struct hci_dev *hdev, __u16 handle) { struct hci_conn_hash *h = &hdev->conn_hash; diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c index 54cfcab7636380a2ced55986a81b0240e9d48d87..aa5404412cbd34320f00954bda71dce65910793c 100644 --- a/net/bluetooth/hci_conn.c +++ b/net/bluetooth/hci_conn.c @@ -2088,6 +2088,9 @@ static int create_big_sync(struct hci_dev *hdev, void *data) u32 flags = 0; int err; + if (!hci_conn_valid(hdev, conn)) + return -ECANCELED; + if (qos->out.phy == 0x02) flags |= MGMT_ADV_FLAG_SEC_2M; @@ -2194,11 +2197,24 @@ static void create_big_complete(struct hci_dev *hdev, void *data, int err) 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_connect_bis(struct hci_dev *hdev, bdaddr_t *dst, @@ -2223,10 +2239,11 @@ struct hci_conn *hci_connect_bis(struct hci_dev *hdev, bdaddr_t *dst, } /* 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); } -- 2.55.0.654.g21b8a5bc05-goog