From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f198.google.com (mail-oi1-f198.google.com [209.85.167.198]) (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 C3417175A88 for ; Sat, 8 Aug 2026 11:53:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.198 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786190034; cv=none; b=eodREfgc50bowYDPPTW7rFwaeb4XSqyOGdywsK2QrOECAH15nE8xdk9y44iLxC2TRVpPJUEonmHlbxO8sK/COlS3KvsdMONmI0Di3w3O1H/ULg6KWw5d9X/1FvP/FOfRzd5Q5nrOgwnRhdTUmNRXmE+ZvjJGnvq/dFGTtIjyXoM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786190034; c=relaxed/simple; bh=JXdHF1o6JBktG9YQUq2uNc5sKkUIOvtTc6bVNGwgFLs=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=Q6QKPp0Xq/vE3q6EPYS9cQvldXT5eXgU7WfeHFVhtZq6EtR33FOF7FbjXSLlPYx/Xmss4EMUl5Io7GoRCno+/oUzOCJzHJLpaD7MZwwgPBVI9Qr0H9/dCsAS6SIwGTE5u7UyIkFbjl/ZbgwDXsOBznr7HA0mbljqz9BB/Vnbmq4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.167.198 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oi1-f198.google.com with SMTP id 5614622812f47-4afa222912eso275120b6e.2 for ; Sat, 08 Aug 2026 04:53:52 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786190031; x=1786794831; h=content-type:to:from:subject:message-id:in-reply-to:date :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to:content-type; bh=ljBbxnS/rEH8DABBP4KSvYhkLS1pxPwkTZ6awPGAzMw=; b=oKs7fJ89qZ+kByTTKCG83eDmv4mTgAnV7/8rRZIqboQHGFwU8t4XKrMoHmeZ5Hq7et l6MeM4Js1MH8CT2Z9xkeQLj0VdgdHRqrBHNfi09dFFeCWORQ4RCl1Fs4lcT/3vzDiA88 9cF80N07acNohORmDdhgzkkhRr4dLtS4Freht4zbFTfw2CnNXOefpkwEoyVPwBLg5bqS q6YqGw+Wvxdyp40GjH4d70ZfAfp72qsjpdiP5Crk4oqkC+x9RckBx6TpkZ+qjagVD9qO DNXE87062vHO0BCBX3HmBQK3gJr2vkrDA8Rtr+7eHPjvMFysPNTJrEmOlHZ90P1x8RKK qShw== X-Gm-Message-State: AOJu0Yz50HmL+S6ZouKKYTOvJek+97EWsh1xP7cRXkKUF8RjwjK+nJNK BvS2pO0PdqTcnXf0lyZZJek5ospkVJiq4kvoE7ynFfLuLo4FEl5GJ0c90Az5welF2OF245R62Op z2eLlRte7U0L53R9CVjnXexL2n0jEvPU+Ld/9dMboLV8gCmcMbtLfZxTBQyc= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:1688:b0:495:e0a9:8c0 with SMTP id 5614622812f47-4b1ab96cd2fmr3528002b6e.11.1786190031664; Sat, 08 Aug 2026 04:53:51 -0700 (PDT) Date: Sat, 08 Aug 2026 04:53:51 -0700 In-Reply-To: <66fbcbc0.050a0220.6bad9.0058.GAE@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a7718cf.b50370da.49fe0.0027.GAE@google.com> Subject: Forwarded: [PATCH] Bluetooth: L2CAP: reject accept queue add unless BT_LISTEN From: syzbot To: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" For archival purposes, forwarding an incoming command email to linux-kernel@vger.kernel.org. *** Subject: [PATCH] Bluetooth: L2CAP: reject accept queue add unless BT_LISTEN Author: pav@iki.fi New items should not be added to parent socket accept queue after last l2cap_sock_cleanup_listen() has run in l2cap_sock_teardown_cb() and state set to BT_CLOSED, as that can result to UAF on dereferencing the dangling parent reference. Add check for sk_state == BT_LISTEN after acquiring sk lock in l2cap_sock_new_connection_cb() to avoid this. Add lock_sock() around sk_state changes where it was missing. That this can trigger appears to be possible since l2cap_chan::state is not consistently guarded by a lock, so data races on it can exist in checking parent pchan->state == BT_LISTEN in l2cap_core. Fixes: 2ff1a41a912d ("Bluetooth: L2CAP: Fix null-ptr-deref in l2cap_sock_state_change_cb()") Reported-by: syzbot+9265e754091c2d27ea29@syzkaller.appspotmail.com --- #syz test net/bluetooth/l2cap_sock.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index 735167f73f31..8c2ac8b911e0 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1568,6 +1568,11 @@ static int l2cap_sock_new_connection_cb(struct l2cap_chan *chan, lock_sock(parent); + if (parent->sk_state != BT_LISTEN) { + release_sock(parent); + return -EINVAL; + } + /* Check for backlog size */ if (sk_acceptq_is_full(parent)) { BT_DBG("backlog full %d", parent->sk_ack_backlog); @@ -1731,10 +1736,14 @@ static void l2cap_sock_state_change_cb(struct l2cap_chan *chan, int state, if (!sk) return; + lock_sock(sk); + sk->sk_state = state; if (err) sk->sk_err = err; + + release_sock(sk); } static struct sk_buff *l2cap_sock_alloc_skb_cb(struct l2cap_chan *chan, @@ -1810,6 +1819,8 @@ static void l2cap_sock_resume_cb(struct l2cap_chan *chan) if (!sk) return; + lock_sock(sk); + if (test_and_clear_bit(FLAG_PENDING_SECURITY, &chan->flags)) { sk->sk_state = BT_CONNECTED; chan->state = BT_CONNECTED; @@ -1817,6 +1828,8 @@ static void l2cap_sock_resume_cb(struct l2cap_chan *chan) clear_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags); sk->sk_state_change(sk); + + release_sock(sk); } static void l2cap_sock_set_shutdown_cb(struct l2cap_chan *chan) -- 2.55.0