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=1793213679; b=H9xwpgEynK2E2ZKaQmP+bH6GS/Jj7mE3TGF1KGNpNIUVFFQQgRfgPVHwo32TPhYvRqSJ V1sHlLjjUIB6g3xSEOAttHmRAOzlTf10+DZG9M5sNGFYr/l1ga/F6k/3VOPlkSQ2X/tU1 cjVqVZo4dm3mZ629cDLOzq7jhXs1nFWErv66Q18/p+EHAvHL/Vz2Y9tgcZL0AjF+7kXx/ mccCf0H88H7XFxJWLmj2vjF8/DrVLJc0jDt8Q4cUpn4GENay+US6fgRtvet6nofetF1tw nSS2xuNLn1NuPG/WY/91Q7faLxETM2UEnJgZE8oscoqR7miJ4EMYoMj6rSv+rUpX0PA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793213679; 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=3LQiqMhLZWd//hlc62SXhxTaV6+ouJHAU1kL1zaaJg0=; b=FkpVGBS3m9hrOi1Hoij9b0huZ25ntUaFpGx38w8KArnWUVy1vDhv+0S3fgD2V3UC7fsX jfALAPGm/J7fFA/+30jz7LVYxJf107zRj5lUC4OmXyMfjVKWVPJYSDsGwVBz3+Ozuf+Rb COOInSFAXL+OWe7i5PuesEqJ0bk7ow30JtMU97alH4X8AS7Jzi8GtEkbN6Xp/NDUq6YCk NySGdbGTpjeY7pFBDEsMkW/ZI43LgeIe/nW4/yg9lW1qu+ZXHoJ8M5YIvEIZR2wolh+Py EjeDwFkX5A5i0Roz14Lbqt3Vm4185BIgV4XNcWNy4CIqBuRXb/SMVLhLEJUa1swawgA== 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=2UT7zL0R; 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 7C1C360A2626; Wed, 28 Oct 2026 18:54:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=2UT7zL0R Received: by smtp.kernel.org (Postfix) with ESMTPSA id CB6C31F031E1; Wed, 28 Oct 2026 18:54:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793213679; bh=3LQiqMhLZWd//hlc62SXhxTaV6+ouJHAU1kL1zaaJg0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=2UT7zL0R4LzSmHKQbgTehsqbHtY1CBnxTVHJFUIqC9d/oL01PkX6KCKmrRN7lbmDb iprUa60sbciBhP3/AF/LOFoqOx2vLp817nY63Krjg6c9JthVCcQKPa2ofYh3MeZUHc DMXd8cP+db5X4nXTiHH9nwt1NI9eRdEHFKz9njQk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Luiz Augusto von Dentz , Sasha Levin Subject: [PATCH 6.1 0592/1887] Bluetooth: af_bluetooth: Fix deadlock Date: Wed, 28 Oct 2026 17:44:48 +0100 Message-ID: <20261028170512.892335614@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170459.200466217@linuxfoundation.org> References: <20261028170459.200466217@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Luiz Augusto von Dentz [ Upstream commit f7b94bdc1ec107c92262716b073b3e816d4784fb ] Attemting to do sock_lock on .recvmsg may cause a deadlock as shown bellow, so instead of using sock_sock this uses sk_receive_queue.lock on bt_sock_ioctl to avoid the UAF: INFO: task kworker/u9:1:121 blocked for more than 30 seconds. Not tainted 6.7.6-lemon #183 Workqueue: hci0 hci_rx_work Call Trace: __schedule+0x37d/0xa00 schedule+0x32/0xe0 __lock_sock+0x68/0xa0 ? __pfx_autoremove_wake_function+0x10/0x10 lock_sock_nested+0x43/0x50 l2cap_sock_recv_cb+0x21/0xa0 l2cap_recv_frame+0x55b/0x30a0 ? psi_task_switch+0xeb/0x270 ? finish_task_switch.isra.0+0x93/0x2a0 hci_rx_work+0x33a/0x3f0 process_one_work+0x13a/0x2f0 worker_thread+0x2f0/0x410 ? __pfx_worker_thread+0x10/0x10 kthread+0xe0/0x110 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x2c/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1b/0x30 Fixes: 2e07e8348ea4 ("Bluetooth: af_bluetooth: Fix Use-After-Free in bt_sock_recvmsg") Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin --- net/bluetooth/af_bluetooth.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c index 2e37841e4835f..212ac760f3d91 100644 --- a/net/bluetooth/af_bluetooth.c +++ b/net/bluetooth/af_bluetooth.c @@ -363,14 +363,11 @@ int bt_sock_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, if (flags & MSG_OOB) return -EOPNOTSUPP; - lock_sock(sk); - skb = skb_recv_datagram(sk, flags, &err); if (!skb) { if (sk->sk_shutdown & RCV_SHUTDOWN) err = 0; - release_sock(sk); return err; } @@ -396,8 +393,6 @@ int bt_sock_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, skb_free_datagram(sk, skb); - release_sock(sk); - if (flags & MSG_TRUNC) copied = skblen; @@ -630,10 +625,11 @@ int bt_sock_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) if (sk->sk_state == BT_LISTEN) return -EINVAL; - lock_sock(sk); + spin_lock(&sk->sk_receive_queue.lock); skb = skb_peek(&sk->sk_receive_queue); amount = skb ? skb->len : 0; - release_sock(sk); + spin_unlock(&sk->sk_receive_queue.lock); + err = put_user(amount, (int __user *)arg); break; -- 2.53.0