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 2E696585978 for ; Fri, 11 Sep 2026 19:54:34 +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=1789156484; cv=none; b=iquFAyaWbna/NdeftS3jo1UeChqXCTps37xfS4gIa/O/tIXtiqZ1jo9zt8A0ZC9wWVH6D0XQliJ4JPSxARPnSzZnSSMbzRUZMsDYtT5R4Tg7Z8QZyw3/BVtneE1xUf6Jkbll28JSlw34XwAqP7seXRSRoT/q+RwWzhrWOkc/nCo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789156484; c=relaxed/simple; bh=YHVYtwZQJ5bh/fiODzp8vn/NJuyupHs1PWFm5QtILvU=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=pAUsH3WoyaDdvbBZdr6rX7URwmL3toMFeLe/ZiF6lfdTfAer545EjPBTOvPelyFm8yL+70WDqomKr25nmKaspmBQDxBkgqIglXa/yrm8WXEqa7S8JRNNDhupsHOv51dpxkRPIDPklgWRjBpHZSTir+eiAdqGUI8R/LtGSkhEY6U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=csk/jEPH; 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="csk/jEPH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3FF3C1F00898; Fri, 11 Sep 2026 19:54:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789156473; bh=/zHg14o5EIKNbrO9i3Oli+Yzf56BbjW+dlMYlC7XTOI=; h=From:To:Cc:Subject:Date:Reply-To; b=csk/jEPHLPLkER9Vjd20TUTgg/poHrue9zrp1iM9x9/LFSqc2kZU875CSMW8Br+uj GnzDrgPkcdDo1ij2TtAAJNXcxUyDXM9nT6NgIvETHwZXYDUsywoVYA/RMM2IBZv92K Zg+pcNq+JDXdPKHykUVi8UDa/FbHPRIvkwaOMn24= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89530: svcrdma: Reject inline replies that overflow the pull-up buffer Date: Fri, 11 Sep 2026 21:43:39 +0200 Message-ID: <2026091116-CVE-2026-89530-71e5@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=3819; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=ssU4fY+6n1Dqg+EzlXz84wO48PO1uyo1ChStEFJAvdc=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLImN4510Jd7LKcmjSkj6due7XxZhPk/XvsvT8Wvv5b OBO+/W9HbEsDIJMDLJiiixftvEc3V9xSNHL0PY0zBxWJpAhDFycAjCRnY0MC3Ze+6RZ1rR13v1s SwlbgaQi3amK2gzzXZmffnrmJjerSfFaU1Rr4F7h8/+0AQ== 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: svcrdma: Reject inline replies that overflow the pull-up buffer An RPC-over-RDMA client can request a reply, such as an NFS READ payload, without providing a Write list or a Reply chunk to carry it. When such a reply needs more scatter/gather entries than the device's Send Queue supports, svc_rdma_pull_up_needed() selects pull-up and svc_rdma_pull_up_reply_msg() linearizes the whole reply into sctxt->sc_xprt_buf. That buffer is only sc_max_req_size bytes, while the reply on this path is bounded only by the client's request, so svc_rdma_xb_linearize() copies past the end of the buffer and corrupts adjacent slab memory. The oversized length is then stored in sc_sges[0].length and posted, so the device also reads beyond the mapped region. The SGE-exhaustion branch is the only pull-up path that can exceed the buffer: the threshold branch pulls up only replies smaller than RPCRDMA_PULLUP_THRESH, and replies that fit the device's SGE budget are sent directly without linearization. Make svc_rdma_pull_up_needed() report -E2BIG when the reply it would pull up cannot fit sc_max_req_size, and fail the request with ERR_CHUNK as RFC 8166 Section 4.5.3 directs rather than dropping the connection. The helper no longer answers a simple yes/no question: it now reports pull-up, no pull-up, or -E2BIG for a reply too large to linearize. Rename svc_rdma_pull_up_needed() to svc_rdma_check_pull_up() so its name no longer implies a boolean predicate. The Linux kernel CVE team has assigned CVE-2026-89530 to this issue. Affected and fixed versions =========================== Issue introduced in 5.0 with commit e248aa7be86e8179f20ac0931774ecd746f3f5bf and fixed in 6.12.109 with commit fcd91b9957462d398792201c239dffaeff1cc8b2 Issue introduced in 5.0 with commit e248aa7be86e8179f20ac0931774ecd746f3f5bf and fixed in 6.18.50 with commit 1949dd1576f7a8aa161b1330c6125df9d53046d5 Issue introduced in 5.0 with commit e248aa7be86e8179f20ac0931774ecd746f3f5bf and fixed in 7.2.4 with commit 8ec60eb51fae37cd3d334ff26e4a7d6fb21ff7cf Issue introduced in 5.0 with commit e248aa7be86e8179f20ac0931774ecd746f3f5bf and fixed in 7.3-rc1 with commit 0fbe20dfe74b783d255bf389a6ea77aa25dc7860 Issue introduced in 4.19.22 with commit 9b65b18f817d9ada2bf67351f24bdcce6789a0bb Issue introduced in 4.20.9 with commit d564356e1919d1178568c19af410cfc1a9076663 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-2026-89530 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/sunrpc/xprtrdma/svc_rdma_sendto.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/fcd91b9957462d398792201c239dffaeff1cc8b2 https://git.kernel.org/stable/c/1949dd1576f7a8aa161b1330c6125df9d53046d5 https://git.kernel.org/stable/c/8ec60eb51fae37cd3d334ff26e4a7d6fb21ff7cf https://git.kernel.org/stable/c/0fbe20dfe74b783d255bf389a6ea77aa25dc7860