From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=95.215.58.155 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794146179; b=n775lWW01gUjmIlXpZ0QiCUttqk+31ZG68h847TFr1EsaDsUmiRmaSv7Gf8RkA/1qG0Z cvKutJ3HEHdnJdY7VjS8FEYmD/+wOIJgS7YEGXGfRqE6UEXZy9L4cUJzwCunBSsqC8G5d 4XIvA5VkUgnK55R+hRDkKGg1zrPVEtY/c3KrQ2hwvMijokogLz1wPAdxYzSjLecQkHeqp 4W9nuZO7C7a+eOrHOJI87Yk75eLeZaHORl0NuZafzGY1kOtp1iBjv9IxTId5jTRNJXu0V U2F/bSPZGFR1XkuCTBPAyT8sZj0oDIjAtYxe1Q1/ldxW+35ul/OblhBF1XvRh+ODBYQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794146179; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:From:To:Cc:Subject:Date:Message-Id: X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding; bh=sqtBH0a18GoP5swPUqLodYJqXwzpxujEm07G1oy5Qjg=; b=jnZXhMEQX0wuA3tHsNCaOBJmuiJF9BANihWKzY4Qq/crd6eDFz99Sh8FrWTdjVkQx4aQ /+gsm8cQO4O//xKQbTIQYj0CTMFTmZw814nNqEfV3kITr8QAtitkfI6DlTzbqGGAs10+r mw8IlaGTVTYX95b+62lbrRJrPiyuoEuBdKRQBpsd9TbpABelkPzdEPoAVTUYJLgagO9co NqE+ZanFCcNt3Dp1b0ZOx3Da/A5n3X2yuEzYfURWsZmup5FstUDnGrVKgK9TJ8zi2x33u SiYbKrm3nmrZL8CEvMBBrAyfbCZxMX3rqiXHgEEk5vuPWY+RZeNkmBfOtZ9Xmyj+e/g== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=MwxDtmUj; arc=none smtp.remote-ip=95.215.58.155 Received: from mta1.migadu.com (out-155.mta1.migadu.com [95.215.58.155]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0045E606A31C for ; Sun, 8 Nov 2026 13:56:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 0045E606A31C Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=MwxDtmUj X-Envelope-To: stable@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=0YQTFfo6Zx+bnkQmwhR7F7qwZFMAvWmY7FYm8gNBzfY=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1794146174; v=1; x=1794750974; b=MwxDtmUjXQQ9yh/gx6Urw71F2U/rZWSdRjMOozocxnRQiYCNY4V/a7KB5Co4PISzXjZwxrqA emVoGpihW4txZvJ/R2OmOMoKddUu35V7XzSLsI+ColwdlOVI3PPSxdoz79rxspr4DbyqAg8ds+L i1oTziYP4RyN72+Li2cIEvLs= X-Envelope-To: stable@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 1156377d6fda6b04; Sun, 08 Nov 2026 13:56:14 +0000 X-Mizu-Trace-ID: 1156377d6fda6b04 X-Migadu-Flow: FLOW_OUT From: Qingfang Deng To: stable@vger.kernel.org Cc: Jakub Kicinski Subject: [PATCH 6.18.y] pppoe: delete session hash entries by pointer match Date: Sun, 8 Nov 2026 21:56:09 +0800 Message-Id: <20261108135609.889-1-qingfang.deng@linux.dev> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20261107051334-failed-6.18-b5b8c81836e2@kernel.org> References: <20261107051334-failed-6.18-b5b8c81836e2@kernel.org> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit [ Upstream commit b5b8c81836e2bec7b444dfa2b14fd14e912e9d63 ] pppoe_connect() copies the requested PPPoE address to a socket before attempting to insert the socket into the session hash table. If the tuple already exists, __set_item() returns -EALREADY, but the copied address and ifindex remain set on the failed socket. Closing that socket then deletes the existing socket's hash entry through pppoe_release(), preventing it from receiving further session traffic. An unprivileged process in the same network namespace can trigger this through a duplicate connection attempt. To avoid the accidental delete, pass the pppox_sock to __delete_item(), and unlink only an entry whose pointer matches the requested socket. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Qingfang Deng Link: https://patch.msgid.link/20261020092118.47416-1-qingfang.deng@linux.dev Signed-off-by: Jakub Kicinski [ Resolve conflict, and remove const qualifier of pppox_sock to match hash_item(). ] Signed-off-by: Qingfang Deng --- drivers/net/ppp/pppoe.c | 22 ++++++++-------------- 1 file changed, 8 insertions(+), 14 deletions(-) diff --git a/drivers/net/ppp/pppoe.c b/drivers/net/ppp/pppoe.c index 7ee63051a161..0bfb048c291a 100644 --- a/drivers/net/ppp/pppoe.c +++ b/drivers/net/ppp/pppoe.c @@ -195,18 +195,16 @@ static int __set_item(struct pppoe_net *pn, struct pppox_sock *po) return 0; } -static void __delete_item(struct pppoe_net *pn, __be16 sid, - char *addr, int ifindex) +static void __delete_item(struct pppoe_net *pn, struct pppox_sock *po) { - int hash = hash_item(sid, addr); + int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote); struct pppox_sock *ret, __rcu **src; ret = rcu_dereference_protected(pn->hash_table[hash], lockdep_is_held(&pn->hash_lock)); src = &pn->hash_table[hash]; while (ret) { - if (cmp_addr(&ret->pppoe_pa, sid, addr) && - ret->pppoe_ifindex == ifindex) { + if (ret == po) { struct pppox_sock *next; next = rcu_dereference_protected(ret->next, @@ -256,11 +254,10 @@ static inline struct pppox_sock *__get_item_by_addr(struct net *net, return pppox_sock; } -static inline void delete_item(struct pppoe_net *pn, __be16 sid, - char *addr, int ifindex) +static void delete_item(struct pppoe_net *pn, struct pppox_sock *po) { spin_lock(&pn->hash_lock); - __delete_item(pn, sid, addr, ifindex); + __delete_item(pn, po); spin_unlock(&pn->hash_lock); } @@ -602,8 +599,7 @@ static int pppoe_release(struct socket *sock) * protect "po" from concurrent updates * on pppoe_flush_dev */ - delete_item(pn, po->pppoe_pa.sid, po->pppoe_pa.remote, - po->pppoe_ifindex); + delete_item(pn, po); sock_orphan(sk); sock->sk = NULL; @@ -653,8 +649,7 @@ static int pppoe_connect(struct socket *sock, struct sockaddr *uservaddr, if (stage_session(po->pppoe_pa.sid)) { pppox_unbind_sock(sk); pn = pppoe_pernet(sock_net(sk)); - delete_item(pn, po->pppoe_pa.sid, - po->pppoe_pa.remote, po->pppoe_ifindex); + delete_item(pn, po); if (po->pppoe_dev) { dev_put(po->pppoe_dev); po->pppoe_dev = NULL; @@ -705,8 +700,7 @@ static int pppoe_connect(struct socket *sock, struct sockaddr *uservaddr, error = ppp_register_net_channel(dev_net(dev), &po->chan); if (error) { - delete_item(pn, po->pppoe_pa.sid, - po->pppoe_pa.remote, po->pppoe_ifindex); + delete_item(pn, po); goto err_put; }