From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5AF4734CFC3 for ; Wed, 22 Jul 2026 13:54:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784728495; cv=none; b=exgDi93g4KMH64SqaggiDaNS3eVoCCQAgWx1e3X4OwROg3I7jXhSg9xBI3xwrjqzmHw2hVZHXgHei0dHvf24M8xdO6fIzoGIfMlzrdtsYcgDjX9gzk4g0BFrF3Hc43oUj1qLj5Y4334abA0qYSMf2I+grE+nFPQf8+Ipdm7Z5xs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784728495; c=relaxed/simple; bh=yLogF2fWHLoGd1hzTiTcsJx0HcL1rtq2NLtIJKbjRUE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Y9GCNMj1EB+9+FBwYdNtUns60LTE1TmCbylrSes53u+IOmhT2icym78X3lqJlvZVlSV2tEmj1QY211Eai+SucMyQG04x4iDQK15XwWmcyboCwbbqdMNIax/4tdLfSC67UVrLBj6cmdH2rKFwiFPpmrHm+2i8vfdFDgTciW8IL38= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TcwzxdIZ; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="TcwzxdIZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9AD021F00A3A; Wed, 22 Jul 2026 13:54:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784728494; bh=dF2QI8H4Uny4s2k/DpyhGNVp5B3nky9gewHGiBujfpw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=TcwzxdIZSHLqCu/Xr5IWTXAI+V/sosfwW8bLHNSwP5PHmICsI6y5ket6dYEN34uG7 pIQEJDpAmhpyJf6vTt8E/Xx7wzSqcTFNdR7Bluy4b6yRhk4uRJxKMZbw3mEBxOFYib LyIHg64f59XudhBpmFuM9GBHrxOoV/YtX778JSzXFEjE89SbBPpglaIwdb5rJEnGUS mKAZK2c9NHcSCaVYOBvsURS5Aj+0m87cuodip75yc0Z4W5DiE5M1ggmp0Az1gFvTwn sQt+URqwdMencfp30yLRiNbAJ3hryFzstN0mLCBgDsKDZWlu4sShQE4TqHn0eraqZy w0JF8guTOrmFg== From: Sasha Levin To: stable@vger.kernel.org Cc: Li Daming , Yuan Tan , Yifan Wu , Juefei Pu , Xin Liu , Ren Wei , David Howells , Marc Dionne , Jeffrey Altman , Simon Horman , linux-afs@lists.infradead.org, stable@kernel.org, Jakub Kicinski , Sasha Levin Subject: [PATCH 6.12.y 2/2] rxrpc: serialize kernel accept preallocation with socket teardown Date: Wed, 22 Jul 2026 09:54:50 -0400 Message-ID: <20260722135450.1365902-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260722135450.1365902-1-sashal@kernel.org> References: <2026072052-carve-yelp-e5c8@gregkh> <20260722135450.1365902-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Li Daming [ Upstream commit dc175389b18c29a5303ee83169ec653adfae3e17 ] rxrpc_kernel_charge_accept() reads rx->backlog without any socket/backlog synchronization and passes that raw pointer into rxrpc_service_prealloc_one(). A concurrent rxrpc_discard_prealloc() sets rx->backlog = NULL and frees the backlog rings, so a kernel preallocation worker can keep using a freed struct rxrpc_backlog while updating *_backlog_head/tail and array slots. Serialize the state check and backlog lookup with the socket lock, and reject kernel preallocation once teardown has disabled listening or discarded the service backlog. Fixes: 00e907127e6f ("rxrpc: Preallocate peers, conns and calls for incoming service requests") Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Signed-off-by: Li Daming Signed-off-by: Ren Wei Signed-off-by: David Howells cc: Marc Dionne cc: Jeffrey Altman cc: Simon Horman cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/20260609140911.838677-6-dhowells@redhat.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/rxrpc/call_accept.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) diff --git a/net/rxrpc/call_accept.c b/net/rxrpc/call_accept.c index 5343fca982bdad..b6da923378f08b 100644 --- a/net/rxrpc/call_accept.c +++ b/net/rxrpc/call_accept.c @@ -470,13 +470,26 @@ int rxrpc_kernel_charge_accept(struct socket *sock, rxrpc_notify_rx_t notify_rx, unsigned long user_call_ID, gfp_t gfp, unsigned int debug_id) { - struct rxrpc_sock *rx = rxrpc_sk(sock->sk); - struct rxrpc_backlog *b = rx->backlog; + struct rxrpc_backlog *b; + struct rxrpc_sock *rx; + struct sock *sk; + int ret; - if (sock->sk->sk_state == RXRPC_CLOSE) - return -ESHUTDOWN; + sk = sock->sk; + rx = rxrpc_sk(sk); + + lock_sock(sk); + if (sk->sk_state != RXRPC_SERVER_LISTENING || !rx->backlog) { + ret = -ESHUTDOWN; + goto out; + } + + b = rx->backlog; + ret = rxrpc_service_prealloc_one(rx, b, notify_rx, user_call_ID, + gfp, debug_id); - return rxrpc_service_prealloc_one(rx, b, notify_rx, user_call_ID, - gfp, debug_id); +out: + release_sock(sk); + return ret; } EXPORT_SYMBOL(rxrpc_kernel_charge_accept); -- 2.53.0