From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f200.google.com (mail-oi1-f200.google.com [209.85.167.200]) (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 153257083C for ; Mon, 28 Sep 2026 01:46:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.200 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790560012; cv=none; b=MUwPEflBvMCXQ1vQpf8x/Zi1Hbwenr2D8/EJPDG8gbK68dBIJoPgfDV5Htt6egjJRV3PLlKKDaW6dwRxDv36mg7BUcdjKxFswQog/wtfw7t2UbEuhhR9qXC283AkcSj3l5Bvy4/AetoYFvkKFxArI8ubhuoGNPtOauDUy6La+SI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790560012; c=relaxed/simple; bh=BGSjq3rD62G6UietoKvI6EZIb3xUlGPHYyIfMCgfESM=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To:Cc: Content-Type; b=PSPskc9l+mfyNrmr50EgIg4PeDkDWMX7NtjjEYU8Upbdjr6vF6SDqaei8XPSKaSEigYjzcpY3k5yNXhKYtKqHOTpG2eIZ8Tcw9w9PuNU9exmGEjcTkM32so7wtvjcxZHcFqK6XdTIxeoW/Qim7mKxCFaH3vMu1U9iTrK1q2g6C0= 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=209.85.167.200 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-f200.google.com with SMTP id 5614622812f47-4ab260600easo5236885b6e.1 for ; Sun, 27 Sep 2026 18:46:50 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790560010; x=1791164810; 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=RH3u4TMhsdNFlANd5Tp5Xa0rdVtCLYtzYuD/aX9jlLU=; b=mk7EZdCxKAZmB9c0aVJOW0iRrYNCRff68aWDjq0ZHso4zXx/mJ+HSuTUlR1sQ8YLRo 3OMssInqdEOlWhcPI1iBetjOjrhxxUvjHHRW3LhZhtwbBZH6S69GS2ahPS4Q/5O8n5Yx 2PVE2Jvb6As2JYYjI+e63uokwattrNBVXCNumLl9+iIyRKmyepGylhKbV4SYZTal/wr6 wuRqW6os5JkDCa8N94EocxFMq9rH7NlxEIhEXyBXXWM2Mf5XNabUkT7ab0Y2rMlJDEsL 0+ex6La8EvxMFf4Gg9PRgy9DY7BXcfFPlfVeDKhtKsJ3f8hogDWnuVvQ5vbrexqFHOUU SFJQ== X-Gm-Message-State: AFuF++lRp7i2Xz1rs5Yf9uzRE2Jun614fPysWq9s1FONSLNooFyJVDij bXvlJvxMastB7Xhohl0iSATCXQtxdHHuOG6zDS570lDNdxCIjJAnllaD5qP6Q8E0V8x/jtuRmWF nQi2FsF8lontlHPkIa7gwJEadeaMOGDiMAo30YDluhVHHxyN6knbuQCW4QEM= Precedence: bulk X-Mailing-List: syzbot@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:6f86:b0:4d6:9133:cfe9 with SMTP id 5614622812f47-4d72d06594amr9809473b6e.46.1790560009952; Sun, 27 Sep 2026 18:46:49 -0700 (PDT) Date: Sun, 27 Sep 2026 18:46:49 -0700 In-Reply-To: <20260928014639.2230819-1-qwe.aldo@gmail.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6ab9c709.e548f532.1ca396.0042.GAE@google.com> Subject: Forwarded: [PATCH] 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: [PATCH] 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 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 cac1b5487..f2530bebe 100644 --- a/net/nfc/llcp_core.c +++ b/net/nfc/llcp_core.c @@ -81,8 +81,14 @@ 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; @@ -1276,6 +1282,10 @@ static void nfc_llcp_recv_dm(struct nfc_llcp_local *local, sk = &llcp_sock->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