From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794590870; b=fxPJFPEi8LZpj8vl98HFolrC/6Sogt3FS+Eqr3HC6vDAN/0pYpkGQZxUk+7uV5e1PELN TGJ8TjZs4BZjbEL46FkYKJFaSJeqSRhj27yX6jy6Q4uEzY86jIlBTawja6hemeWL5wKTS B1LZdpUpdJlHlExLmQCyhA6Dml2ca5Ns4SrskdOlvlyrggTM2Gu2r/iZKeA6BieZwDMhA AaYj+UKi/YpImAgRDSNgqSodulxEhLSLm3t4hK5HHxCM04dbFfgU975VSe4lC4BfuTWMv cVXU+WcgqcXir8dacXCTvh+WLg38qWJwIDQKq1Q8Xut3oqLo2lijlkspUWL3mWJFqJw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794590870; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=auGQMaPhnvz/DkXoEdqfvbI6iqoJ2jVDP5VD49Xuz28=; b=rhX8SZpt1LUX4dfAP+DcJVQdvlGe3MkZ5UD5wGtaZsLKJ/KRIEc7AfJw7tFYM92Hl/IB TF7tuelfhxzkk5Vi9MhGfxK1ybX9DNiuTaI2wqi6GILlHTHlMZQqjCQXpv6nvns9kKr6m vut+0QU6vO+8T2KebJaH+FbvzkehHM81jDhEEY8RGMMGZA4zRkudGl7HbS8TDocL3IV2U bGT+F/PTw3Kg+M7TK2Y3cR/0cVtK3ztcTQLgemGUvruXe4D9GBvSgKtV07P+4UxgHt5jb RgxCyNguo0wox9q+oS+nhIqclYNBkqQlqglY+IvdVcuAC7Zo8z/zE3Fmm1hDidPAOJg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=bSJis7WR; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6F37D606D4A5; Fri, 13 Nov 2026 17:27:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=bSJis7WR Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1C0651F000C5; Fri, 13 Nov 2026 17:27:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794590870; bh=auGQMaPhnvz/DkXoEdqfvbI6iqoJ2jVDP5VD49Xuz28=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=bSJis7WRR9tHDT1f/0hM1FvN7HknY6GtBvhXWrssTWKKxm6qiRfWFWpwdpXgfnP8g 4vv001kpjHjLXRSF1+Dp/OggythcdeF9pVSRw3lcp2HWugYy+Bt41NP0XF0OfHuE5T P3vDTMUSPr6w0wn8W7bzls2YxGx5d3FJNUmGcswo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Qingfang Deng , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.12 068/670] pppoe: delete session hash entries by pointer match Date: Fri, 13 Nov 2026 10:43:52 -0500 Message-ID: <20261113153813.811931602@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261113153811.177190860@linuxfoundation.org> References: <20261113153811.177190860@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Qingfang Deng [ 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 Signed-off-by: Sasha Levin --- 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 8ff2024dde604..293b6fb1c1e98 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; } -- 2.53.0