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 79EB4392C56 for ; Sun, 19 Jul 2026 15:40:22 +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=1784475623; cv=none; b=kub+so+nJ4glfUuKPklGUhqIoKELMoN+z86c8gxwbbHXdeniMApp7MoCPS5YFmwQJuvSCW/H5ORVeSoAq7g/xccUAYrG3M7cW5Nqb/d4Gw/rTXQcphw3OwOSviQSA8oST/JORuGKW0xSF4x3aAUehx/YL9Pfu45QQEpcmHfKurg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784475623; c=relaxed/simple; bh=L+ZODIKlH2GwIka55ibg38KCpaPyG5WjheREnG04LRk=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=iH7559ny9VNYj+qavJEsGunS+smkaxxH6A/jOKMJsbIFim4KIqpMRjxgFF2Jgb9T5JzBpPrOrk5/ExpTenmumwrOg4XmR/Dp1q3xVwDLbPXQIoWovKXRLlsl4ACf5hqAcveYp9nX8Ke00mv3mvUDQkGkh/hFBiFXn/AV0rGWyjA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=QtKXbrMY; 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="QtKXbrMY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8E2381F000E9; Sun, 19 Jul 2026 15:40:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784475622; bh=xplIFcODOTrejlHJUe28YsFnRs3SuOM4dlyijCW1RIA=; h=From:To:Cc:Subject:Date:Reply-To; b=QtKXbrMYJV5bIDcEA81WRp0jtL589MVx3TVbpKVGsETcTddijMlrrnGUscwpmvvC1 bCOUjodvNsP//kxzqLv+Y7n7VJ/aVIEQLF+jd/WamRBqkOvcYEgAKs2iJoqsCXL1MV couR1YHZpr0bI30fW9WxQNHSjJVpOB2dJf6YyqRo= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-64026: rxrpc: Fix DATA decrypt vs splice() by copying data to buffer in recvmsg Date: Sun, 19 Jul 2026 17:38:08 +0200 Message-ID: <2026071902-CVE-2026-64026-372d@gregkh> X-Mailer: git-send-email 2.55.0 Reply-To: , Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=4491; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=ERGWyz6FnxHtAGSUIapMTVyuU7iLe2mYIUz3qk1MLiI=; b=owGbwMvMwCRo6H6F97bub03G02pJDFkx76OnCcjwfm1qfm4zhzVsxfe8n08nveLaKyFrZ3qAK 7xo0vuqjlgWBkEmBlkxRZYv23iO7q84pOhlaHsaZg4rE8gQBi5OAZjIDUGG+b5/KmPF4j+++nBt 5SOedi8J/R1lYQzzfTpENi4NuHn6IuNezw2NqblPNu3oBgA= X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit From: Greg Kroah-Hartman Description =========== In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix DATA decrypt vs splice() by copying data to buffer in recvmsg This improves the fix for CVE-2026-43500. Fix the pagecache corruption from in-place decryption of a DATA packet transmitted locally by splice() by getting rid of the packet sharing in the I/O thread and unconditionally extracting the packet content into a bounce buffer in which the buffer is decrypted. recvmsg() (or the kernel equivalent) then copies the data from the bounce buffer to the destination buffer. The sk_buff then remains unmodified. This has an additional advantage in that the packet is then arranged in the buffer with the correct alignment required for the crypto algorithms to process directly. The performance of the crypto does seem to be a little faster and, surprisingly, the unencrypted performance doesn't seem to change much - possibly due to removing complexity from the I/O thread. Yet another advantage is that the I/O thread doesn't have to copy packets which would slow down packet distribution, ACK generation, etc.. The buffer belongs to the call and is allocated initially at 2K, sufficiently large to hold a whole jumbo subpacket, but the buffer will be increased in size if needed. However, to take this work, MSG_PEEK may cause a later packet to be decrypted into the buffer, in which case the earlier one will need re-decrypting for a subsequent recvmsg(). Note that rx_pkt_offset may legitimately see 0 as a valid offset now, so switch to using USHRT_MAX to indicate an invalid offset. Note also that I would generally prefer to replace the buffers of the current sk_buff with a new kmalloc'd buffer of the right size, ditching the old data and frags as this makes the handling of MSG_PEEK easier and removes the re-decryption issue, but this looks like quite a complicated thing to achieve. skb_morph() looks half way to what I want, but I don't want to have to allocate a new sk_buff. The Linux kernel CVE team has assigned CVE-2026-64026 to this issue. Affected and fixed versions =========================== Issue introduced in 5.3 with commit d0d5c0cd1e711c98703f3544c1e6fc1372898de5 and fixed in 6.6.143 with commit a05bf6d9e621fa71e89ccebe3047ba45218d7b38 Issue introduced in 5.3 with commit d0d5c0cd1e711c98703f3544c1e6fc1372898de5 and fixed in 6.12.93 with commit b94a6ccbaf1104dd980150a65fdeb2f69d17d2f5 Issue introduced in 5.3 with commit d0d5c0cd1e711c98703f3544c1e6fc1372898de5 and fixed in 6.18.35 with commit 46cb765e2e5ad52303ea157e10d370bb6b7acbbf Issue introduced in 5.3 with commit d0d5c0cd1e711c98703f3544c1e6fc1372898de5 and fixed in 7.0.11 with commit c580087743712112778a06d65a4074053072d7bf Issue introduced in 5.3 with commit d0d5c0cd1e711c98703f3544c1e6fc1372898de5 and fixed in 7.1 with commit d2bc90cf6c75cb96d2ce549be6c35efa3099d25b Please see https://www.kernel.org for a full list of currently supported kernel versions by the kernel community. Unaffected versions might change over time as fixes are backported to older supported kernel versions. The official CVE entry at https://cve.org/CVERecord/?id=CVE-2026-64026 will be updated if fixes are backported, please check that for the most up to date information about this issue. Affected files ============== The file(s) affected by this issue are: net/rxrpc/ar-internal.h net/rxrpc/call_event.c net/rxrpc/call_object.c net/rxrpc/insecure.c net/rxrpc/recvmsg.c net/rxrpc/rxgk.c net/rxrpc/rxgk_common.h net/rxrpc/rxkad.c Mitigation ========== The Linux kernel CVE team recommends that you update to the latest stable kernel version for this, and many other bugfixes. Individual changes are never tested alone, but rather are part of a larger kernel release. Cherry-picking individual commits is not recommended or supported by the Linux kernel community at all. If however, updating to the latest release is impossible, the individual changes to resolve this issue can be found at these commits: https://git.kernel.org/stable/c/a05bf6d9e621fa71e89ccebe3047ba45218d7b38 https://git.kernel.org/stable/c/b94a6ccbaf1104dd980150a65fdeb2f69d17d2f5 https://git.kernel.org/stable/c/46cb765e2e5ad52303ea157e10d370bb6b7acbbf https://git.kernel.org/stable/c/c580087743712112778a06d65a4074053072d7bf https://git.kernel.org/stable/c/d2bc90cf6c75cb96d2ce549be6c35efa3099d25b