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 332593BED38 for ; Sun, 27 Sep 2026 23:23:58 +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=1790551440; cv=none; b=LGwQQZLJUl3TJUf70rryG316MwJxFxD+fHRPi+F4qdNLn7VK+QYgAmws+6EYeFUgmfCzTVpAl022wtb2ihhc58qEHNbAFZX43bayyyQLC6UNbn18FP0cUf4VgMRaVe+8wj9uNh+Y8G1LKh45XxPuphlq1Uxz/uc7gDz8GJXzodU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790551440; c=relaxed/simple; bh=bRyFcsVjDYOiPQLlH3oX5aeZ8Ia1BLK8qaCWKtCBBnA=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To:Cc: Content-Type; b=CLLRWPwCs4TroYUU5Lplj9ANqt1Nk5eiExnEkAvLLyxJCIluDBjMHeqGGXQ9gJxnsCb0lSaIwIEeT6XbWrbLqWD8hqUFFD7igz3igXiSAVi0d0Py9ERN+jjHxrRO9O9g/Ol1NH67Ct07VX9c4/sjVR1GbWssydGfpRYAl3TeVQI= 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 5614622812f47-4b28d7ffab1so4373523b6e.1 for ; Sun, 27 Sep 2026 16:23:58 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790551438; x=1791156238; h=content-type:cc: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=xyZDKoTGeP1svw19j8H2HBS2WMauDaO9iXzwJKLa9kg=; b=mYPia5EY5hdwja6S7ID4u6+TDhpl1Il5UAW9OvbDIuMKJnb/tpwK66MI7TmLl6jIRm UK+Dli/8ZOXM7kvPcwfsch3NI2PjeY2DvOkcTvtqDC9V3lM2/s4E3xU6pnguLtSDF/1G zyR6+KaY9BTq7AT34Hn70QSR+ENsOoJietAdJ7lnW4sGqBVfJWmToNwRhLVFt4ze8JR4 rKOI/hlo8HXxyGilpLYgip6btrl1PALM04XNIxaZZBZYH5FvOtMVtSuqV2XnzE32LnSs VX5PyyJ4MgISW+I7t5m74pVGNOm38sU3lgW5Jig+MPbYYlWQQNgQDdnCc4OUoQiAB+KN OCHg== X-Gm-Message-State: AFuF++mMUKa0EZ1Jua3A2+mVCxdhsSaEctPsAHfpCV1Mz8QKFZofkklK cs3eUhL2HZQRMYg1hG/tyH5IDkoaENhq/A9OszkAwScSrTchsM3Bhl45eMUyOhs90OIlgstao1F qjyBujGFtNfS/P8Bj3JLb/f5tznZnRRv6awJN17XBqJGWcX8VBt9iAw7a0Hg= Precedence: bulk X-Mailing-List: syzbot@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:16aa:b0:4c9:f7ca:82b1 with SMTP id 5614622812f47-4d72cd3640amr8798887b6e.33.1790551438083; Sun, 27 Sep 2026 16:23:58 -0700 (PDT) Date: Sun, 27 Sep 2026 16:23:58 -0700 In-Reply-To: <20260927232347.2160670-1-qwe.aldo@gmail.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6ab9a58e.80e1c6cc.1e8e5f.0067.GAE@google.com> Subject: Forwarded: nfc: llcp: clear stale device pointers on socket close From: syzbot To: syzbot@lists.linux.dev Cc: syzbot , qwe.aldo@gmail.com Content-Type: text/plain; charset="UTF-8" For archival purposes, forwarding an incoming command email to syzbot@lists.linux.dev. *** Subject: nfc: llcp: clear stale device pointers on socket close Author: qwe.aldo@gmail.com #syz test nfc_llcp_socket_release() and nfc_llcp_recv_dm() can move a socket to LLCP_CLOSED without clearing llcp_sock->dev. A bound socket never owned a device reference (bind puts its temporary ref), and a connected socket's reference is already released here. A later reconnect attempt would then put a device reference the socket does not own. Clear the pointer when a socket becomes closed so that the reconnect cleanup only puts references it actually holds. Signed-off-by: Aldo Ariel Panzardo --- net/nfc/llcp_core.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/net/nfc/llcp_core.c b/net/nfc/llcp_core.c index 74bf81700..174e92ea5 100644 --- a/net/nfc/llcp_core.c +++ b/net/nfc/llcp_core.c @@ -95,8 +95,14 @@ static void nfc_llcp_socket_release(struct nfc_llcp_local *local, bool device, nfc_llcp_socket_purge(llcp_sock); - if (sk->sk_state == LLCP_CONNECTED) + if (sk->sk_state == LLCP_CONNECTED) { nfc_put_device(llcp_sock->dev); + llcp_sock->dev = NULL; + } else if (sk->sk_state == LLCP_BOUND || + sk->sk_state == LLCP_LISTEN) { + /* bind() already dropped its temporary device reference. */ + llcp_sock->dev = NULL; + } if (sk->sk_state == LLCP_LISTEN) { struct nfc_llcp_sock *lsk, *n; @@ -1329,6 +1335,10 @@ static void nfc_llcp_recv_dm(struct nfc_llcp_local *local, if (connecting) nfc_llcp_sock_unlink(&local->connecting_sockets, sk); + /* Bound and listening sockets do not own a device reference. */ + if (sk->sk_state == LLCP_BOUND || sk->sk_state == LLCP_LISTEN) + llcp_sock->dev = NULL; + sk->sk_err = ENXIO; sk->sk_state = LLCP_CLOSED; sk->sk_state_change(sk); -- 2.43.0