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 2886B4A441C for ; Thu, 24 Sep 2026 15:52:29 +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=1790265150; cv=none; b=IdjCISS1m2mIOOW+HRPhppsueJGZK5IxpEqghrmyd/nl9Bb+OR3WeTZW36pT6mBzy/H2gkcolxfCVE70XcBAFCoWAZhClrlXnXNDytgZdC2We1UGxidoH1Sd5Q20MsZzCOugrCJx4pWM0RwfWhdUbIWpUo6Rvr72hFHkqDKw4Eg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790265150; c=relaxed/simple; bh=Hy3VeuRVIUdlHr/RlLelgjsMVznUJMXx0c+EFrGUy3k=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=dsYIF04Vc9DvIWY52YGJjkKeViLKUEhxZ+AxyqSAoZ36IzGjuPz5/XWMGL5TlqnaIZxPeTTKGKE/vRmFfRpZq4EdYXyp/hiIVofnNvfntL9Gd5gHY3dyE2J8dsKCINDeGmw3B5L3plqhG+z8jXCUHkL0S+OH3hjeMQRIj/8qA0o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=AbTzSD1M; 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="AbTzSD1M" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4BE891F000FF; Thu, 24 Sep 2026 15:52:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790265149; bh=4s4fA8EZ1nfBA3tvwkJxf2jcCVdk9bgUH7Z/6QU1P6U=; h=From:To:Cc:Subject:Date:Reply-To; b=AbTzSD1MuRKvmolangWq3K+C4a3mwUUjJOuLFe0ok5uvb7V7PPobvXvNaP3lGD/gb zDnEctOXVTWykEvstklnT0WDRJeslDJ6am8I0W+rkqCxk0Uc22KgP9Hq0aus6tbfZn Vjv9Tyng8xR5ZTSsPzApkdK1NNPK7j9koHbdjZMs= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-93256: arm64: hibernate: mask DAIF before restoring hibernated kernel Date: Thu, 24 Sep 2026 17:51:16 +0200 Message-ID: <2026092408-CVE-2026-93256-ec2a@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=4619; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=wXpGmQaHczAKEfCMu2dZnhNUdh0HQD9P4tzGvbswHCE=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlb3d4ElF3c13qUXyuaxbD917HPZw+b/w5LkDmxb1fv4 ifvPfzcOmJZGASZGGTFFFm+bOM5ur/ikKKXoe1pmDmsTCBDGLg4BWAi9y0Y5gds32D7ft3E6MPM onsZZLd7+CdKLGSYH6Nyx9tgTU9N9ceHeYv6lQL/OWYHAQA= 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: arm64: hibernate: mask DAIF before restoring hibernated kernel The arm64 hibernate code manages the exception masking in an unsound way, leading to potential crashes and/or warnings during resume. When a hibernation image is saved in `swsusp_arch_suspend()`, all DAIF exceptions are masked (by virtue of `local_daif_save()`), and the suspended image is saved assuming that all DAIF exceptions will remain masked when the image is restored. When a hibernation image is resumed by `swsusp_arch_resume()`, only interrupts are masked (by virtue of `local_irq_disable()` in `resume_target_kernel()`). When pseudo-NMI is enabled the DAIF.IF bits will be clear, and regardless of pseudo-NMI the DAIF.DA bits will be clear. This means that there are two problems: (1) It is possible to take Debug, SError, or pseudo-NMI exceptions during the resume process. This is unsafe, as during the resume process both the old ane new kernels will tranisently be in an inconsistent state, and swsusp_arch_suspend_exit() won't retain an executable mapping of any exception vectors. Any exception taken here will be fatal and silent. (2) When re-entering the resumed kernel, some DAIF bits will be clear unexpectedly. This permits Debug, SError, or pseudo-NMI exceptions to be taken for a short period while the resumed kernel is not yet in a consistent state. This is detected by CONFIG_ARM64_DEBUG_PRIORITY_MASKING. Avoid these issues by masking all DAIF exceptions during resume. The Linux kernel CVE team has assigned CVE-2026-93256 to this issue. Affected and fixed versions =========================== Issue introduced in 4.7 with commit 82869ac57b5d3b550446932c918dbf2caf020c9e and fixed in 5.10.270 with commit c9c671e9ab87b639720db8f7f8648bdf0f3bc8ec Issue introduced in 4.7 with commit 82869ac57b5d3b550446932c918dbf2caf020c9e and fixed in 5.15.221 with commit 099ad3edcef1d955d9f5d6aab16ae78ecdfd4cda Issue introduced in 4.7 with commit 82869ac57b5d3b550446932c918dbf2caf020c9e and fixed in 6.1.188 with commit 716c41bd476334afb943308be9ff2142e34461b7 Issue introduced in 4.7 with commit 82869ac57b5d3b550446932c918dbf2caf020c9e and fixed in 6.6.157 with commit 5370853041a3cb53a125b77528586278f64b378b Issue introduced in 4.7 with commit 82869ac57b5d3b550446932c918dbf2caf020c9e and fixed in 6.12.110 with commit 290c5b0c9fc0c61fb1c41421ed2394f955206ea0 Issue introduced in 4.7 with commit 82869ac57b5d3b550446932c918dbf2caf020c9e and fixed in 6.18.52 with commit 012823494e20c3cce622982ebd3fd6971be39ad2 Issue introduced in 4.7 with commit 82869ac57b5d3b550446932c918dbf2caf020c9e and fixed in 7.2.6 with commit d736ace2c491623c9ab5e73744085e93e9ae3ebe Issue introduced in 4.7 with commit 82869ac57b5d3b550446932c918dbf2caf020c9e and fixed in 7.3-rc1 with commit 684bde100117931f4c51c644a95f42f2dab041bc 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-2026-93256 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: arch/arm64/kernel/hibernate.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/c9c671e9ab87b639720db8f7f8648bdf0f3bc8ec https://git.kernel.org/stable/c/099ad3edcef1d955d9f5d6aab16ae78ecdfd4cda https://git.kernel.org/stable/c/716c41bd476334afb943308be9ff2142e34461b7 https://git.kernel.org/stable/c/5370853041a3cb53a125b77528586278f64b378b https://git.kernel.org/stable/c/290c5b0c9fc0c61fb1c41421ed2394f955206ea0 https://git.kernel.org/stable/c/012823494e20c3cce622982ebd3fd6971be39ad2 https://git.kernel.org/stable/c/d736ace2c491623c9ab5e73744085e93e9ae3ebe https://git.kernel.org/stable/c/684bde100117931f4c51c644a95f42f2dab041bc