From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 9F3D2316197 for ; Thu, 14 May 2026 15:53:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778774000; cv=none; b=Gtxz16KfnEJsdqJgA7YILtNR0ERFPsVmwty7qW/MCGsGpRwfsImBupDWE5yHT5eKrC3h9BuVGst+Z1twmjqIbPDkIqUwO/XgeGPtwcOvWHGRjq/yxk6/hfpiUUoJWfnOVrv0hFnF4mCgZkEOsN5b25Ig77AZnCj59AuwdBzp074= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778774000; c=relaxed/simple; bh=l+rLmMg/hVX2hhsETNj9o6r4r9qcBCC30BsnxOxqUDs=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=NwO9LyjNaDZRlXl5lL3Do+eLEs45P27D+VbkM42EHhTosbk53cGh8MifW6SpC6Z4RnTJZU8a5NxVcDl0xjuxr3x5Z7iQuNzUQ7gS9xay79fO6oCXNotXn7cIenZD/a0FGFhkq2n2ZuJiFIY/nIlWlP6QWUBsJaFbPuersYGSfrw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=f8YV4Yj6; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="f8YV4Yj6" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1778773997; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=wPJD4cSvgohi5bUcmXKy4d3gwoNT23eATH97E0wX5lw=; b=f8YV4Yj6aVnGFNvDvQDzPh1VBg/zx5S6FdS53xcrEquDONcJFDL97jRU2of+uIrMwT1yla 6eWpkrzqAaA6MV4gNwY/wMd8bqX/AnBcKX+xqyRd6ZtQJ1CTEuiQTMXrenpjXf3YRby5Am 4a0k2EYfJnlc278syF/lQCHweP5hstU= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-139-aVvCfNSXPFq9J8wwaUEzPw-1; Thu, 14 May 2026 11:53:14 -0400 X-MC-Unique: aVvCfNSXPFq9J8wwaUEzPw-1 X-Mimecast-MFC-AGG-ID: aVvCfNSXPFq9J8wwaUEzPw_1778773993 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 47831180061E; Thu, 14 May 2026 15:53:12 +0000 (UTC) Received: from warthog.procyon.org.com (unknown [10.44.48.83]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 37AF130002DA; Thu, 14 May 2026 15:53:07 +0000 (UTC) From: David Howells To: netdev@vger.kernel.org Cc: David Howells , Hyunwoo Kim , Marc Dionne , Jakub Kicinski , "David S. Miller" , Eric Dumazet , Paolo Abeni , Simon Horman , linux-afs@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH net v3 0/4] rxrpc: Better fix for DATA/RESPONSE decrypt vs splice() Date: Thu, 14 May 2026 16:52:58 +0100 Message-ID: <20260514155304.2249591-1-dhowells@redhat.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Here are two patches containing better fixes for the in-place decryption of DATA and RESPONSE packets that can corrupt pagecache spliced into UDP packets and sent to an AF_RXRPC server [CVE-2026-43500], plus a patch to precheck the length of rxgk-secured DATA packets. [!] Note that Hyunwoo Kim's fix is included as that is a prerequisite for the main patches to build. This is in Linus's tree, but not yet net/main. Of the main patches, one patch fixes DATA decryption by having recvmsg unconditionally extract the data into a flat bounce buffer and, if need be, decrypt it there. It doesn't seem to cause a performance problem to do this even on unencrypted packets; for encrypted packets it makes sure the content is correctly aligned for crypto which seems to get a small performance gain. Further, it means that DATA packets are no longer copied in the I/O thread, avoiding a slowdown of the protocol engine that runs there. The other main patch fixes RESPONSE decryption by having the connection event handler worker copy the data to a flat buffer and, again, decrypt it there. This simplifies RESPONSE handling. With these two fixes, the data content of the received sk_buff no longer gets altered. David The patches can be found here also: http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=rxrpc-fixes Changes ======= ver #3) - Fixed Sashiko review comments[2]: - Fix wrong abort codes. - Fix skipped rxgk_put. - Fix some mis-sizeofs. - Fix flipped length check comparison. ver #2) - In rxrpc_verify_data(): - Flipped the order of the buffer size comparison. - Used max() not umin() to calculate the minimum buffer size. - In rxrpc_verify_response(), returned -ENOMEM rather than uninitialised ret. - Removed the xdr wrappers that were added to make backporting easier. - Fixed Sashiko review comments[1]: - Added length prechecking of received packets secured with RxGK, thereby avoiding looking at an unallocated buffer. - Added missing crypto free. [1] https://sashiko.dev/#/patchset/20260511160753.607296-1-dhowells%40redhat.com [2] https://sashiko.dev/#/patchset/20260513131941.1439155-1-dhowells%40redhat.com David Howells (3): crypto/krb5, rxrpc: Fix lack of pre-decrypt/pre-verify length checks rxrpc: Fix DATA decrypt vs splice() by copying data to buffer in recvmsg rxrpc: Fix RESPONSE packet verification to extract skb to a linear buffer Hyunwoo Kim (1): rxrpc: Also unshare DATA/RESPONSE packets when paged frags are present Documentation/crypto/krb5.rst | 17 +++- crypto/krb5/krb5_api.c | 54 ++++++++++-- include/crypto/krb5.h | 9 +- include/trace/events/rxrpc.h | 1 + net/rxrpc/ar-internal.h | 14 +-- net/rxrpc/call_event.c | 20 +---- net/rxrpc/call_object.c | 2 + net/rxrpc/conn_event.c | 29 +++--- net/rxrpc/insecure.c | 8 +- net/rxrpc/recvmsg.c | 76 +++++++++++++--- net/rxrpc/rxgk.c | 160 ++++++++++++++-------------------- net/rxrpc/rxgk_app.c | 46 ++++------ net/rxrpc/rxgk_common.h | 66 +++++++------- net/rxrpc/rxkad.c | 115 +++++++++--------------- 14 files changed, 315 insertions(+), 302 deletions(-)