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 4F312175BF; Mon, 12 May 2025 18:02:34 +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=1747072954; cv=none; b=NaxbuvNEbG3PsiPMmHwvierdYxcxfwdEPN6OOIjTbq2r2LeTQpPiUPcQg86m/fXD7HZRNCnmTT5v7siPS5/3v5+fjdwVJSwGRA5oa2w75PtDbiMMpEbMYfU3MNzjzLALRod7ZyKIx7ICQEKRKgUQr2tvVzt7tGqG1FjhGmhUMqg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747072954; c=relaxed/simple; bh=558hvcznL4I3AQ5hmpEAFnR7CbFAYAK91zXgkjndlmc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pzvF8fYDKAPDgqI6MoOrvvV8fCdWg88+qjI34dHNZRShCrZZVRVXu3g+vLv50lffihz4eu0zDU72Y6d9FM9C3eBFRDUqwb6rYSx66PEsmWH/pPDWnDNJqWXmSOk76mQdhp7rE7ByFx9v3YGMrQZab7ucFxwmOnvclRhop/xlO/0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=I7FtXqfL; 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="I7FtXqfL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CB878C4CEE7; Mon, 12 May 2025 18:02:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1747072954; bh=558hvcznL4I3AQ5hmpEAFnR7CbFAYAK91zXgkjndlmc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=I7FtXqfL+leMivPYAwWbjpM9MEJatUjWbgnlOaesXzA5kByKRLwD1Ytlwr0DpNt0B Dsj3GuvddN+DJdv/SlHrjae0FEDhJIKr/Obi7SUYc7qXq5FPAHJqcUWzL5KnkOgza2 /6gFqnfk19TeqvSZI0rJGUkPXVCT+Rl9Ctps5MFQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Tom Lendacky , "Mike Rapoport (Microsoft)" Subject: [PATCH 6.12 109/184] memblock: Accept allocated memory before use in memblock_double_array() Date: Mon, 12 May 2025 19:45:10 +0200 Message-ID: <20250512172046.266559308@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250512172041.624042835@linuxfoundation.org> References: <20250512172041.624042835@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tom Lendacky commit da8bf5daa5e55a6af2b285ecda460d6454712ff4 upstream. When increasing the array size in memblock_double_array() and the slab is not yet available, a call to memblock_find_in_range() is used to reserve/allocate memory. However, the range returned may not have been accepted, which can result in a crash when booting an SNP guest: RIP: 0010:memcpy_orig+0x68/0x130 Code: ... RSP: 0000:ffffffff9cc03ce8 EFLAGS: 00010006 RAX: ff11001ff83e5000 RBX: 0000000000000000 RCX: fffffffffffff000 RDX: 0000000000000bc0 RSI: ffffffff9dba8860 RDI: ff11001ff83e5c00 RBP: 0000000000002000 R08: 0000000000000000 R09: 0000000000002000 R10: 000000207fffe000 R11: 0000040000000000 R12: ffffffff9d06ef78 R13: ff11001ff83e5000 R14: ffffffff9dba7c60 R15: 0000000000000c00 memblock_double_array+0xff/0x310 memblock_add_range+0x1fb/0x2f0 memblock_reserve+0x4f/0xa0 memblock_alloc_range_nid+0xac/0x130 memblock_alloc_internal+0x53/0xc0 memblock_alloc_try_nid+0x3d/0xa0 swiotlb_init_remap+0x149/0x2f0 mem_init+0xb/0xb0 mm_core_init+0x8f/0x350 start_kernel+0x17e/0x5d0 x86_64_start_reservations+0x14/0x30 x86_64_start_kernel+0x92/0xa0 secondary_startup_64_no_verify+0x194/0x19b Mitigate this by calling accept_memory() on the memory range returned before the slab is available. Prior to v6.12, the accept_memory() interface used a 'start' and 'end' parameter instead of 'start' and 'size', therefore the accept_memory() call must be adjusted to specify 'start + size' for 'end' when applying to kernels prior to v6.12. Cc: stable@vger.kernel.org # see patch description, needs adjustments for <= 6.11 Fixes: dcdfdd40fa82 ("mm: Add support for unaccepted memory") Signed-off-by: Tom Lendacky Link: https://lore.kernel.org/r/da1ac73bf4ded761e21b4e4bb5178382a580cd73.1746725050.git.thomas.lendacky@amd.com Signed-off-by: Mike Rapoport (Microsoft) Signed-off-by: Greg Kroah-Hartman --- mm/memblock.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) --- a/mm/memblock.c +++ b/mm/memblock.c @@ -456,7 +456,14 @@ static int __init_memblock memblock_doub min(new_area_start, memblock.current_limit), new_alloc_size, PAGE_SIZE); - new_array = addr ? __va(addr) : NULL; + if (addr) { + /* The memory may not have been accepted, yet. */ + accept_memory(addr, new_alloc_size); + + new_array = __va(addr); + } else { + new_array = NULL; + } } if (!addr) { pr_err("memblock: Failed to double %s array from %ld to %ld entries !\n",