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 3CD2D3911D6; Sat, 12 Sep 2026 19:59:37 +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=1789243178; cv=none; b=ugHIj3XlOvaqeHiEzehwc4TRwB4e7pjoY9mAA73+nO9TZSVCPIZEp/AtpiF61HJnrRt/hbxtReXM7eyuApkou8InTd1NNbKKynoaM18Kz0fWvVGB8CoH8nFZUjLLWk4qmFaOrWPwxP2AdWE2KBtW3vrQE5Bcl77+K6nygOiDjPk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789243178; c=relaxed/simple; bh=6RGOsdwBXDy9ZZJqBRELKIQ1IGxhkO8lADSRSwkkZTE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=guQnej2MR5Ivn378kPZ37l8UH2TIs/XvQPDL6ZH50s3PTb09Tf5Jx1lZmwFx+b4J58zz7RL7+qnenJ8Mtt4UnwiuWkIs6Ct1yWwNwI9QJOC1Stha6L0/beRTQnJgYxjyJhewxSZkmiQvNxxNXS1h+x4q+7OATYNGAyr9GEFv8PQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=n9kjLqT0; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="n9kjLqT0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 997D51F000FF; Sat, 12 Sep 2026 19:59:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789243177; bh=bKvj0DlI6pesTastMD4iVJDL3Xy1iUuBIj10dyjBisU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=n9kjLqT0PaKa8csZc9YouNOM8mFTRwjm/SJLPVULUBjpLN8RMaBWbOkfwSH40lvMS /hmXFQKB0sEXRINuXEGU9kJecDoNOaz0Q4SC9v+tEWiOOOLBIomG5I4JxmVf80nNfm snQD1mf55Y96Oraky1OJoJuWTSxQ2ixrkAWkx6JY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Xiang Mei , Weiming Shi , Jeff Layton , Trond Myklebust , Sasha Levin Subject: [PATCH 5.10 665/798] SUNRPC: check rpc_sockaddr2uaddr() return value in rpcb_register_inet4/6 Date: Sat, 12 Sep 2026 09:04:53 +0200 Message-ID: <20260912065532.348177495@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065516.948645775@linuxfoundation.org> References: <20260912065516.948645775@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Weiming Shi [ Upstream commit fd22370226a0d8109045d0831fd5aaadee921693 ] rpcb_register_inet4() and rpcb_register_inet6() store the result of rpc_sockaddr2uaddr() into map->r_addr without checking it for NULL. rpc_sockaddr2uaddr() returns NULL when its final kstrdup() fails, and the unchecked NULL is then carried into the synchronous RPCBPROC_SET encode path: rpcb_register_call() -> rpc_call_sync() -> rpcb_enc_getaddr() -> encode_rpcb_string(), whose first statement is strlen(string), dereferencing NULL and oopsing the kernel. The crash reproduces under failslab on v6.12; with KASAN the NULL dereference surfaces as a fault on the shadow of address zero: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000 [#1] PREEMPT SMP KASAN RIP: 0010:strlen (lib/string.c:409) Call Trace: encode_rpcb_string (net/sunrpc/rpcb_clnt.c:890) rpcb_enc_getaddr (net/sunrpc/rpcb_clnt.c:910) rpcauth_wrap_req_encode (net/sunrpc/auth.c:745) call_encode (net/sunrpc/clnt.c:1966) __rpc_execute (net/sunrpc/sched.c:952) rpc_run_task (net/sunrpc/clnt.c:1243) rpc_call_sync (net/sunrpc/clnt.c:1272) rpcb_v4_register (net/sunrpc/rpcb_clnt.c:500) svc_generic_rpcbind_set nfsd_rpcbind_set svc_register svc_setup_socket svc_addsock write_ports nfsctl_transaction_write vfs_write The crash is reachable when an in-kernel RPC service (nfsd, lockd, nfs-callback) registers with the local rpcbind under enough memory pressure for the small GFP_KERNEL kstrdup() in rpc_sockaddr2uaddr() to fail. The asynchronous getport path already handles this exact failure mode by returning -ENOMEM; only the two register helpers omit the check. Mirror that handling: bail out with -ENOMEM when rpc_sockaddr2uaddr() returns NULL, before the address is fed into the encoder. Fixes: d77385f23830 ("SUNRPC: Fix rpc_sockaddr2uaddr") Reported-by: Xiang Mei Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Weiming Shi Reviewed-by: Jeff Layton Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin --- net/sunrpc/rpcb_clnt.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c index f1bb4fd2a2707..86fc4661646e1 100644 --- a/net/sunrpc/rpcb_clnt.c +++ b/net/sunrpc/rpcb_clnt.c @@ -465,6 +465,8 @@ static int rpcb_register_inet4(struct sunrpc_net *sn, int result; map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL); + if (!map->r_addr) + return -ENOMEM; msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET]; if (port != 0) { @@ -491,6 +493,8 @@ static int rpcb_register_inet6(struct sunrpc_net *sn, int result; map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL); + if (!map->r_addr) + return -ENOMEM; msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET]; if (port != 0) { -- 2.53.0