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 9E2BA3AA187; Fri, 4 Sep 2026 05:43:23 +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=1788500604; cv=none; b=uTUYQpjxNKLS6ARiq0ttzLDHOF7bZiwGBWdkmQh5g2mrYz9g9HWVxVmQS9HgGnCW2BZwfRGnBCMSo9GHeYVys9OZdz8vStofARN2/RPUNaZ7hB42RTDkzeBn3Tphpx4/I7/9uRTWtq4omnchxv8UKoV2PRo+kA4jpQHAhDPMPJg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788500604; c=relaxed/simple; bh=M31Ev4xexaZCgR4NSE3Wnx8ZsqtiI7BpiL4Wt4P4y8c=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=QCl8iDOkpFZR5PTYtUxl9G17WYhdy6v5XW3XsGBjGy5/BFkJGyHylsp5V/Q50y3KXmsjziX+0UIhHIysxpSKdNbwlG03//aYfyb3aq7h2LHo3EvsykPeLHDEfAcBEt2y+J57DKgdcI7EQxKuh1izEhpOza5iobe2fvYgNbXHuaQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ymMmUBtQ; 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="ymMmUBtQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 049191F00A3D; Fri, 4 Sep 2026 05:43:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788500603; bh=OJPz/TznN6hKrjRXRrCS/HZU8Cw/MEuIB4cEsrUuLl4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ymMmUBtQM0E68vpQ/MMlWTbwAc3q1E2amtoJh11wRG1f2yqmplKDB70jsiLUIchva PqEkmL1TpQPDne+ihP1E1ftehwEQTZeY+INVVBJIJanNdt4P3Tfl6eW3V4Bk7jYH1P a8EFeHU/J7xsKLL4VAHYz8uAJIxAmRkwuEImwW+g= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Chris Mason , Chuck Lever Subject: [PATCH 6.18 113/552] nfsd: size fh_verify server sockaddr slot by xpt_locallen Date: Fri, 4 Sep 2026 06:54:30 +0200 Message-ID: <20260904045750.467054498@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260904045747.813364717@linuxfoundation.org> References: <20260904045747.813364717@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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chris Mason commit 71d068490098b1d23c63b2345e40675d3a1ca763 upstream. The nfsd_fh_verify and nfsd_fh_verify_err tracepoints declare the server sockaddr slot sized by xpt_remotelen but fill it from xpt_local using xpt_locallen: TP_STRUCT__entry( ... __sockaddr(server, rqstp->rq_xprt->xpt_remotelen) ... ) TP_fast_assign( ... __assign_sockaddr(server, &rqstp->rq_xprt->xpt_local, rqstp->rq_xprt->xpt_locallen); ... ) When xpt_locallen exceeds xpt_remotelen, __assign_sockaddr's memcpy writes past the reserved ring-buffer slot. In the reverse direction (xpt_locallen < xpt_remotelen) the slot is oversized and the unwritten tail leaks prior ring-buffer contents to trace consumers. The write-past-end case is reachable on NFS/UDP. svc_xprt_set_remote() is only called from svc_tcp_accept() (net/sunrpc/svcsock.c) and from the RDMA connect path; svc_create_socket() for UDP calls only svc_xprt_set_local(), so xpt_remotelen stays 0 for the xprt's lifetime. Every fh_verify trace for an NFSv2/v3-over-UDP request then copies 16 or 28 bytes from xpt_local into a zero-byte slot. The other NFSD tracepoints that record the server address (NFSD_TRACE_PROC_CALL_FIELDS, NFSD_TRACE_PROC_RES_FIELDS, SVC_RQST_ENDPOINT_FIELDS) already size the server slot by xpt_locallen; nfsd_fh_verify and nfsd_fh_verify_err were the only exceptions. Fix by sizing the server slot with xpt_locallen so the declared slot matches the copy length. The client slot and its assignment already agree on xpt_remotelen and are left untouched. Fixes: 051382885552 ("NFSD: Instrument fh_verify()") Fixes: 948755efc951 ("NFSD: Replace dprintk() call site in fh_verify()") Cc: stable@vger.kernel.org Assisted-by: kres:claude-opus-4-7 Signed-off-by: Chris Mason Link: https://patch.msgid.link/20260531-nfsd-testing-v1-1-7bfa481b0540@kernel.org Signed-off-by: Chuck Lever Signed-off-by: Greg Kroah-Hartman --- fs/nfsd/trace.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/fs/nfsd/trace.h +++ b/fs/nfsd/trace.h @@ -236,7 +236,7 @@ TRACE_EVENT_CONDITION(nfsd_fh_verify, TP_CONDITION(rqstp != NULL), TP_STRUCT__entry( __field(unsigned int, netns_ino) - __sockaddr(server, rqstp->rq_xprt->xpt_remotelen) + __sockaddr(server, rqstp->rq_xprt->xpt_locallen) __sockaddr(client, rqstp->rq_xprt->xpt_remotelen) __field(u32, xid) __field(u32, fh_hash) @@ -275,7 +275,7 @@ TRACE_EVENT_CONDITION(nfsd_fh_verify_err TP_CONDITION(rqstp != NULL && error), TP_STRUCT__entry( __field(unsigned int, netns_ino) - __sockaddr(server, rqstp->rq_xprt->xpt_remotelen) + __sockaddr(server, rqstp->rq_xprt->xpt_locallen) __sockaddr(client, rqstp->rq_xprt->xpt_remotelen) __field(u32, xid) __field(u32, fh_hash)