From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.77 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794146511; b=ERhVYnT31oH9PaYTSBfDo5MTBldd7M6CTZAs5HKHhVhSImLRNgYDjbtnwy4B/aTzaWDO WXLZ63R3ONBEeDHVBj4wQSGgs+tZVCliGTN6KKDSpQP2f2XY+pgv4Q2RkHjosniVsnSzn a5UNTKgySuD6g4h7FtK+i9ShK+z2XyEd+zJ2pfC6Iu97iFx7GHz2srTi3+brNFrPp6RLI 2IaxkmX+8wyylH4zxvvIa+tlbQSKknXW8x9/9ttsQ3ylIVTo5YXrOcc6nrppRRM5NQxap CcZLVOgQN0ALFmhmJPrDJ+Rlco019hK7kk/3SZS4b/z1mqoudfrlEJ0FYyM3EmE6yfw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794146511; 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=zAQJbBXK85zhqnp6Sy8iRos+KnUH1gw70gkQ2aOh+90=; b=vbOuUkZ+94aY4tUoDIw5IKRxOfiAnV9BaEW+KLWautoHJ//csQRH1je9FQPsA0mvZfU5 +i+ZneQoIvTA9FE8pIU3JFDJVS/JvR4FHybxwLQIvQ3Lr9VPcqhCPLESqQHn9GvwGWzHR r9k8T9q60GZzZp6yRMIwid56CDJwls6L0snWPLXmTH3MQAT/6Gd2RxsWA163tmylE2STe R7OqBfBLU53mmxuNwiLmm9VEZm+R9xGMYREhBHAfzbUBKAQBVaFhqPhf8WloCwr8Q5qwY nIZfb2iX9eKuorjx75vFCAloXRzjpKMcWSo8E/Ww3HPgKyv2sECTJAuFZQwIo9U8UWA== 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=gyJDtw1O; arc=none smtp.remote-ip=91.218.175.77 Received: from mta0.migadu.com (out-77.mta0.migadu.com [91.218.175.77]) (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 EF782606A31C for ; Sun, 8 Nov 2026 14:01:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org EF782606A31C 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=gyJDtw1O X-Envelope-To: stable@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=HjVZPtkRA01m0fgGyDnvvNCRvaaaXCOerbCRxZkDG8Q=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1794146507; v=1; x=1794751307; b=gyJDtw1OHWTueJSrFbE9M6Q9FeXI7GJBm8kIILXHYJKu9jS6IFJNZx9y86K4Hx5DaNjx60WZ ADzt/pSpPknIOSTAT/GIlwAu2vGthKXfOQtu8/5NqR4lbOc3yyUfBIZWbS5VJBHuExB355QJqbf XH3xNmXRbW76XfiDvsfGxa+Q= X-Envelope-To: stable@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 08f775a7004b422a; Sun, 08 Nov 2026 14:01:47 +0000 X-Mizu-Trace-ID: 08f775a7004b422a X-Migadu-Flow: FLOW_OUT From: Qingfang Deng To: stable@vger.kernel.org Cc: Jakub Kicinski Subject: [PATCH 6.12.y 6.6.y 6.1.y 5.15.y 5.10.y] pppoe: delete session hash entries by pointer match Date: Sun, 8 Nov 2026 22:01:44 +0800 Message-Id: <20261108140144.1081-1-qingfang.deng@linux.dev> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20261107052514-failed-6.12-b5b8c81836e2@kernel.org> References: <20261107052514-failed-6.12-b5b8c81836e2@kernel.org> <20261107053805-failed-6.6-b5b8c81836e2@kernel.org> <20261107055315-failed-6.1-b5b8c81836e2@kernel.org> <20261107061023-failed-5.15-b5b8c81836e2@kernel.org> <20261107062733-failed-5.10-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 8ff2024dde60..293b6fb1c1e9 100644 --- a/drivers/net/ppp/pppoe.c +++ b/drivers/net/ppp/pppoe.c @@ -194,18 +194,16 @@ 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, **src; ret = pn->hash_table[hash]; src = &pn->hash_table[hash]; while (ret) { - if (cmp_addr(&ret->pppoe_pa, sid, addr) && - ret->pppoe_ifindex == ifindex) { + if (ret == po) { *src = ret->next; break; } @@ -255,11 +253,10 @@ 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) { write_lock_bh(&pn->hash_lock); - __delete_item(pn, sid, addr, ifindex); + __delete_item(pn, po); write_unlock_bh(&pn->hash_lock); } @@ -599,8 +596,7 @@ 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; @@ -651,8 +647,7 @@ 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; @@ -703,8 +698,7 @@ 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; }