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 DBA3C3DEAE0 for ; Tue, 6 Oct 2026 10:25:17 +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=1791282319; cv=none; b=KVKYywHlXUoU3j6MuGqZzXlXQ13RX/fg8DYVjZQC6VtBWuSJu6Uip9MhT4lLFtkSlutLIrffpFbpi3pCFLdoq1vdPl6krxVZ4G8zIaGmX3N8edzu/EaI8/9fBTtfqn8dlpi+4CPTgeI3t/xjJi0I9qCzNnLtg4DY/cBKBiRLWQE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791282319; c=relaxed/simple; bh=A14D8Adc6u5gdL3jNQWO0BBkQLz7toP0aBD4gVRfwF0=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=iPP0YrlMFXiBzDIaZ51LuRXke4k4T7Tv34FticzP5Ou92dPLNVJphHfYyZ8azEzsQHgV/bvFY0naJTA0FlLmrI0THvIPei3DYssvwdYqrVrlEYxsUHNACLN6IUF3LOVojBK/Yu64xINSLDjy4PMu0gXoI20iKPgny1bV7SrRilg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=CMT2erkV; 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="CMT2erkV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0A41D1F000FF; Tue, 6 Oct 2026 10:25:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1791282317; bh=mevzTlsZlq+iUZift62ZTlyEGf6PJlWOpz/ksLGojIk=; h=From:To:Cc:Subject:Date:Reply-To; b=CMT2erkVn6Jf5WMAbKL7PDdjEqvRYLQFWtDkwMSo7imkDzgX5D8SKXXQLy1CTkq/j Hbm+fvqk9qBKT7IDgkuiSiMQVFFV176bT+mGODrAP6gBRJiexrWdnwkQRfD8zAHZj7 34Uww+jmUhyofLLxUz4QCw5myeDcfXKUwZEU3J6w= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-98253: RDMA/ucma: Serialize join and leave on copy_to_user failure Date: Tue, 6 Oct 2026 10:45:54 +0200 Message-ID: <2026100655-CVE-2026-98253-71fd@gregkh> X-Mailer: git-send-email 2.56.0 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=4171; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=+mjMD1ixKJ08uEeSRnNlOUDCXLTxPaUP9TfbcEjUMkc=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlHtrKnxpfO2iu1/y//vPOfckIKMmUZOG/9WXX3Sf2n7 n/3mS0TOmJZGASZGGTFFFm+bOM5ur/ikKKXoe1pmDmsTCBDGLg4BWAipf0Mc6U3aQbGr2m5ErFB at60Q7/zUtUXVDDMFb1aNjUjRXiJzZpDIZXb/su9cJq4FAA= 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: RDMA/ucma: Serialize join and leave on copy_to_user failure rdma_join_multicast() queues RoCE work that later reads the ucma_multicast through event->param.ud.private_data, then list_add()s the CMA multicast at the head of id_priv->mc_list. rdma_leave_multicast() matches only by sockaddr and destroys the first hit. ucma_process_join() used to drop ctx->mutex after a successful join and retake it only if copy_to_user() failed. Two concurrent JOIN_MCAST calls with the same address can therefore insert a second CMA entry before the first thread's leave. leave then cancels the newer work and the older worker still dereferences the ucma_multicast that the first thread frees. Keep ctx->mutex held from rdma_join_multicast() through copy_to_user() and, on -EFAULT, through rdma_leave_multicast() so leave cannot miss this join. Do not leave if join itself failed: that path never published this address on mc_list, and a leave-by-addr would destroy an earlier successful join. The Linux kernel CVE team has assigned CVE-2026-98253 to this issue. Affected and fixed versions =========================== Issue introduced in 5.10.20 with commit 60d613b39e8d0c9f3b526e9c96445422b4562d76 and fixed in 5.10.271 with commit 29b9ed83d8bfab5c6e11fcbf1aa836aa4ae26cb9 Issue introduced in 5.12 with commit fe454dc31e84f8c14cb8942fcb61666c9f40745b and fixed in 5.15.222 with commit 52172e11bd074ccaded21740ffeb67123f01dd00 Issue introduced in 5.12 with commit fe454dc31e84f8c14cb8942fcb61666c9f40745b and fixed in 6.1.189 with commit 01e29d0d78a8f66f221625720a04939eef5ec1f6 Issue introduced in 5.12 with commit fe454dc31e84f8c14cb8942fcb61666c9f40745b and fixed in 6.6.158 with commit ae805d204cf1f15b87d1bf3529b4c649f3519420 Issue introduced in 5.12 with commit fe454dc31e84f8c14cb8942fcb61666c9f40745b and fixed in 6.12.112 with commit 43c4e24bd10370fc976f6220518049ce71419399 Issue introduced in 5.12 with commit fe454dc31e84f8c14cb8942fcb61666c9f40745b and fixed in 6.18.54 with commit 01cbdb724c584d7772fd25af2e4dfdf8527ce0d5 Issue introduced in 5.12 with commit fe454dc31e84f8c14cb8942fcb61666c9f40745b and fixed in 7.2.8 with commit 83610ee5e498fa5bfcb80031d2b959baea276bf6 Issue introduced in 5.12 with commit fe454dc31e84f8c14cb8942fcb61666c9f40745b and fixed in 7.3-rc4 with commit 662ade4de9ff5eceb0820a9f8e9fac70ba6a815b Issue introduced in 5.11.3 with commit a3262b3884dd67b4c5632ce7cdf9cff9d1a575d4 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-2026-98253 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: drivers/infiniband/core/ucma.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/29b9ed83d8bfab5c6e11fcbf1aa836aa4ae26cb9 https://git.kernel.org/stable/c/52172e11bd074ccaded21740ffeb67123f01dd00 https://git.kernel.org/stable/c/01e29d0d78a8f66f221625720a04939eef5ec1f6 https://git.kernel.org/stable/c/ae805d204cf1f15b87d1bf3529b4c649f3519420 https://git.kernel.org/stable/c/43c4e24bd10370fc976f6220518049ce71419399 https://git.kernel.org/stable/c/01cbdb724c584d7772fd25af2e4dfdf8527ce0d5 https://git.kernel.org/stable/c/83610ee5e498fa5bfcb80031d2b959baea276bf6 https://git.kernel.org/stable/c/662ade4de9ff5eceb0820a9f8e9fac70ba6a815b