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 70ABF3DDDDB for ; Fri, 8 May 2026 13:42:02 +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=1778247722; cv=none; b=FJ12BFNajgTgeEPNKTxJ4yBs91WvWOVrsL1ZJuMIREQCCy625AH4cQbQuuIb8lXrqr816hci0A5ZjmmXAFNdZbbar63D1T02Ozxz2LXJs1rhZFVnWQi1jB1iCf02YPRXyHaQOnqr42NU88AbonurRc1cFXlXTBx1HIvDOWYk0fQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778247722; c=relaxed/simple; bh=h8vTOSf9GC1dWXAkr6Uv/34T/XYwJFPYxROds5pOnqE=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=LTFuhGVFmV/9j+XT6rvhO/k9q/1ecCAz5kUpHgO0PB997P082I9FxMYyCYmvv59P+R43ifvGKF/EqcCEmyrhu3lgAv/5RM0KbP26wA6HZKBwNX8UgVA6hUOpzNBd3hIV4FtEpPcGqRVueOnJtV6DbvL9Wx/+Z+lKq5H9FIE0Q38= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=vfsG3FdY; 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="vfsG3FdY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E7D14C2BCB0; Fri, 8 May 2026 13:42:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1778247722; bh=h8vTOSf9GC1dWXAkr6Uv/34T/XYwJFPYxROds5pOnqE=; h=From:To:Cc:Subject:Date:Reply-To:From; b=vfsG3FdYxdK5a4bwc2WLI2RRHDU7zoQgxqsbM+VyLZ6yVxaqb2nb91MQJker2YfPm 6ttry/zPIRqvv4vGFG0AHNrEVeEAeA5zA7uC7ybRsFutIX6oBWYwA1O5l96mx4ZGC5 ymyxqJOzAt6firc87kQo4KmJf2lmURssD6Ymyotc= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-43348: mshv_vtl: Fix vmemmap_shift exceeding MAX_FOLIO_ORDER Date: Fri, 8 May 2026 15:41:56 +0200 Message-ID: <2026050855-CVE-2026-43348-5331@gregkh> X-Mailer: git-send-email 2.54.0 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=2921; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=rU1cFvSHIv3FbrdXDuoQC6Yy1/AZqYgdlRNIEZyqYBE=; b=owGbwMvMwCRo6H6F97bub03G02pJDJl/XygfDz7WoGfF86Vy3eElOovDuq/+ycj54lGseDjvy U1GB7b/HbEsDIJMDLJiiixftvEc3V9xSNHL0PY0zBxWJpAhDFycAjARqfUMc6XC739YtyQ0dYvt F5ULDy8sN3W5I8ywYGXB03W552asny/1Y+HRM7J65gpSTAA= 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: mshv_vtl: Fix vmemmap_shift exceeding MAX_FOLIO_ORDER When registering VTL0 memory via MSHV_ADD_VTL0_MEMORY, the kernel computes pgmap->vmemmap_shift as the number of trailing zeros in the OR of start_pfn and last_pfn, intending to use the largest compound page order both endpoints are aligned to. However, this value is not clamped to MAX_FOLIO_ORDER, so a sufficiently aligned range (e.g. physical range [0x800000000000, 0x800080000000), corresponding to start_pfn=0x800000000 with 35 trailing zeros) can produce a shift larger than what memremap_pages() accepts, triggering a WARN and returning -EINVAL: WARNING: ... memremap_pages+0x512/0x650 requested folio size unsupported The MAX_FOLIO_ORDER check was added by commit 646b67d57589 ("mm/memremap: reject unreasonable folio/compound page sizes in memremap_pages()"). Fix this by clamping vmemmap_shift to MAX_FOLIO_ORDER so we always request the largest order the kernel supports, in those cases, rather than an out-of-range value. Also fix the error path to propagate the actual error code from devm_memremap_pages() instead of hard-coding -EFAULT, which was masking the real -EINVAL return. The Linux kernel CVE team has assigned CVE-2026-43348 to this issue. Affected and fixed versions =========================== Issue introduced in 6.19 with commit 7bfe3b8ea6e30437e01fcb8e4f56ef6e4d986d0f and fixed in 7.0.2 with commit a142ca4b6481e71498712800b20e0c0fcf02843b Issue introduced in 6.19 with commit 7bfe3b8ea6e30437e01fcb8e4f56ef6e4d986d0f and fixed in 7.1-rc1 with commit 404cd6bffe17e25e0f94ed2775ffdd6cd10ac3fd 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-2026-43348 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/hv/mshv_vtl_main.c include/uapi/linux/mshv.h 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/a142ca4b6481e71498712800b20e0c0fcf02843b https://git.kernel.org/stable/c/404cd6bffe17e25e0f94ed2775ffdd6cd10ac3fd