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 D4A2D38837C; Sat, 12 Sep 2026 19:09:25 +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=1789240167; cv=none; b=h8lkl0ZE7N43m4cTBFThAEfusVwydaM8H8/BoWML5IZKTx42rZRD9T64DOh/ercICwS+8a84CHz7o3DB4n+7cshS++8XisEiG93LIe/0F4blSEG6I7OgV5UTot2tnrT/DlcAyj16/OoOH7ChEdl0KLk/HEFJ05t4n9KTWUWTA/Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789240167; c=relaxed/simple; bh=Yyv2AXNiYtwswJzfvUteAddZFZ7SiAuwuyH7oaMqdx4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jxGCogZ7+VjQJiVxvcJ7fw7kharTjb+2NvQ2Twg/sw2wjQZxDS2BoB/5p93apEI3ZPm2wKTlcN69+L66CyFes7t/sHFWU51UgqoHR3g7w+M10Whb986bCrSFNAeXMm5fk+T2b6xPFovvzORUMxFYtwy5qYuQc3Ra00K9IORhf8Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=1sRZSds6; 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="1sRZSds6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3F2061F000FF; Sat, 12 Sep 2026 19:09:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789240165; bh=fQ9PgaJFgqv3MavuOZfNPP1M8P19NgWEkdToXICmqwA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=1sRZSds6YKHCVUsANyzH5U9kX4Vqm+99HV+6BFjTR2Uht+NzMs5nEadZGxUok05bB HcgSnb3rw0yRlDsT60e6rIpI7rhnjjElal8C/8/Rkb2UVw9LaOCRo85AlTF05e5QuN Z3qExycgOflKg7FP4ZQSgXcgkJWYaVAt8GVnbcZ0= 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 5.15 769/935] SUNRPC: check rpc_sockaddr2uaddr() return value in rpcb_register_inet4/6 Date: Sat, 12 Sep 2026 09:03:19 +0200 Message-ID: <20260912065544.468337259@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065526.833703348@linuxfoundation.org> References: <20260912065526.833703348@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 5.15-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 c49f9295fce97..b17becfb46b7f 100644 --- a/net/sunrpc/rpcb_clnt.c +++ b/net/sunrpc/rpcb_clnt.c @@ -467,6 +467,8 @@ 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) { @@ -493,6 +495,8 @@ 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