From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 4069320E328 for ; Wed, 12 Feb 2025 13:28:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739366888; cv=none; b=TErGz+PIt5jv098ZAigM3Ct/R7fPapFEX8yxeoHFhS1AS3ZfWtQA2NWbpniGv2sHnrziGmZ89c/C6Z7BjKgFCeLRCTTaOeMgVj343RMgnKb+CvcNRYcM0oW93Zz92mgf8e/j3Q36d70i4N8Q0V/2qP1XCv9/QQqqdM47IgEso+s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739366888; c=relaxed/simple; bh=aXIYfE97AixgSybjlbX0u9AjvtdxSk14gdowHmeic7A=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=t1VU4xqvcv0NNq/Gn/g54OMKrNTIx7UxDH/Y3ctIKpMn+IbL1Qt4LLs/Y3suLXBHQRp90COQy2ECD0Ky91y5PTJZEdC5DaSMeOOY8BC0WKieLnjPamSp18GKmu8OkPv/xISWyTii1OG7ye81GIWIDrPMS7bAtH5aEpbk40cNoYE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=pAIdbyj5; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="pAIdbyj5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 470A0C4CEDF; Wed, 12 Feb 2025 13:28:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1739366887; bh=aXIYfE97AixgSybjlbX0u9AjvtdxSk14gdowHmeic7A=; h=From:To:Cc:Subject:Date:Reply-to:From; b=pAIdbyj5RMnytS5YSkC9/3XuMF9IwiprlVChWQ0G+TrcAf4be+Tb1hLmEn3KoOabW R9k4Xnt9z4BhM35EkpyM9jNwWWEwkn54D++wJdOS7XkcDhucgO2QFXKs66qmUTSLSV LPnTkXFy+xv2QUFeOy/FWDb78fYxzk69dSyZz4bo= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2024-57951: hrtimers: Handle CPU state correctly on hotplug Date: Wed, 12 Feb 2025 14:26:57 +0100 Message-ID: <2025021256-CVE-2024-57951-691d@gregkh> X-Mailer: git-send-email 2.48.1 Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Reply-to: , X-Developer-Signature: v=1; a=openpgp-sha256; l=4304; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=aXIYfE97AixgSybjlbX0u9AjvtdxSk14gdowHmeic7A=; b=owGbwMvMwCRo6H6F97bub03G02pJDOlrFi4InnvVwl77/k0LpS+O79tcfK6rXrr5Y+PCGxVG2 +tiWjqqO2JZGASZGGTFFFm+bOM5ur/ikKKXoe1pmDmsTCBDGLg4BWAix/gY5gqyaJUtzfhk7uH7 aoZFzKrwmc/tmhjmZ5xkDpglXe+z1fyVVamtaf+OHzu5AQ== X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit Description =========== In the Linux kernel, the following vulnerability has been resolved: hrtimers: Handle CPU state correctly on hotplug Consider a scenario where a CPU transitions from CPUHP_ONLINE to halfway through a CPU hotunplug down to CPUHP_HRTIMERS_PREPARE, and then back to CPUHP_ONLINE: Since hrtimers_prepare_cpu() does not run, cpu_base.hres_active remains set to 1 throughout. However, during a CPU unplug operation, the tick and the clockevents are shut down at CPUHP_AP_TICK_DYING. On return to the online state, for instance CFS incorrectly assumes that the hrtick is already active, and the chance of the clockevent device to transition to oneshot mode is also lost forever for the CPU, unless it goes back to a lower state than CPUHP_HRTIMERS_PREPARE once. This round-trip reveals another issue; cpu_base.online is not set to 1 after the transition, which appears as a WARN_ON_ONCE in enqueue_hrtimer(). Aside of that, the bulk of the per CPU state is not reset either, which means there are dangling pointers in the worst case. Address this by adding a corresponding startup() callback, which resets the stale per CPU state and sets the online flag. [ tglx: Make the new callback unconditionally available, remove the online modification in the prepare() callback and clear the remaining state in the starting callback instead of the prepare callback ] The Linux kernel CVE team has assigned CVE-2024-57951 to this issue. Affected and fixed versions =========================== Issue introduced in 5.4.264 with commit 54d0d83a53508d687fd4a225f8aa1f18559562d0 and fixed in 5.4.290 with commit 95e4f62df23f4df1ce6ef897d44b8e23c260921a Issue introduced in 5.10.204 with commit 7f4c89400d2997939f6971c7981cc780a219e36b and fixed in 5.10.234 with commit 14984139f1f2768883332965db566ef26db609e7 Issue introduced in 5.15.143 with commit 6fcbcc6c8e52650749692c7613cbe71bf601670d and fixed in 5.15.177 with commit 15b453db41d36184cf0ccc21e7df624014ab6a1a Issue introduced in 6.1.68 with commit 75b5016ce325f1ef9c63e5398a1064cf8a7a7354 and fixed in 6.1.127 with commit 3d41dbf82e10c44e53ea602398ab002baec27e75 Issue introduced in 6.6.7 with commit 53f408cad05bb987af860af22f4151e5a18e6ee8 and fixed in 6.6.74 with commit a5cbbea145b400e40540c34816d16d36e0374fbc Issue introduced in 6.7 with commit 5c0930ccaad5a74d74e8b18b648c5eb21ed2fe94 and fixed in 6.12.11 with commit 38492f6ee883c7b1d33338bf531a62cff69b4b28 Issue introduced in 6.7 with commit 5c0930ccaad5a74d74e8b18b648c5eb21ed2fe94 and fixed in 6.13 with commit 2f8dea1692eef2b7ba6a256246ed82c365fdc686 Issue introduced in 4.19.302 with commit 9a2fc41acb69dd4e2a58d0c04346c3333c2341fc 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-2024-57951 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: include/linux/hrtimer.h kernel/cpu.c kernel/time/hrtimer.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/95e4f62df23f4df1ce6ef897d44b8e23c260921a https://git.kernel.org/stable/c/14984139f1f2768883332965db566ef26db609e7 https://git.kernel.org/stable/c/15b453db41d36184cf0ccc21e7df624014ab6a1a https://git.kernel.org/stable/c/3d41dbf82e10c44e53ea602398ab002baec27e75 https://git.kernel.org/stable/c/a5cbbea145b400e40540c34816d16d36e0374fbc https://git.kernel.org/stable/c/38492f6ee883c7b1d33338bf531a62cff69b4b28 https://git.kernel.org/stable/c/2f8dea1692eef2b7ba6a256246ed82c365fdc686