From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Mon, 4 Dec 2017 15:08:04 +0100 Subject: [PATCH] x86/mm/dump_pagetables: Add page table directory to the debugfs VFS hierarchy MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit CVE-2017-5754 The upcoming support for dumping the kernel and the user space page tables of the current process would create more random files in the top level debugfs directory. Add a page table directory and move the existing file to it. Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Cc: Andy Lutomirski Cc: Boris Ostrovsky Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: David Laight Cc: Denys Vlasenko Cc: Eduardo Valentin Cc: Greg KH Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Will Deacon Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Signed-off-by: Ingo Molnar (cherry picked from commit 75298aa179d56cd64f54e58a19fffc8ab922b4c0) Signed-off-by: Andy Whitcroft Signed-off-by: Kleber Sacilotto de Souza (cherry picked from commit ae5c4af9bbefed4adc12075c28fb5889547c99cc) Signed-off-by: Fabian Grünbichler --- arch/x86/mm/debug_pagetables.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/arch/x86/mm/debug_pagetables.c b/arch/x86/mm/debug_pagetables.c index bfcffdf6c577..d1449fb6dc7a 100644 --- a/arch/x86/mm/debug_pagetables.c +++ b/arch/x86/mm/debug_pagetables.c @@ -22,21 +22,26 @@ static const struct file_operations ptdump_fops = { .release = single_release, }; -static struct dentry *pe; +static struct dentry *dir, *pe; static int __init pt_dump_debug_init(void) { - pe = debugfs_create_file("kernel_page_tables", S_IRUSR, NULL, NULL, - &ptdump_fops); - if (!pe) + dir = debugfs_create_dir("page_tables", NULL); + if (!dir) return -ENOMEM; + pe = debugfs_create_file("kernel", 0400, dir, NULL, &ptdump_fops); + if (!pe) + goto err; return 0; +err: + debugfs_remove_recursive(dir); + return -ENOMEM; } static void __exit pt_dump_debug_exit(void) { - debugfs_remove_recursive(pe); + debugfs_remove_recursive(dir); } module_init(pt_dump_debug_init); -- 2.14.2