From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f69.google.com (mail-wm0-f69.google.com [74.125.82.69]) by kanga.kvack.org (Postfix) with ESMTP id 279246B000D for ; Thu, 5 Jul 2018 10:55:51 -0400 (EDT) Received: by mail-wm0-f69.google.com with SMTP id x18-v6so4801201wmc.7 for ; Thu, 05 Jul 2018 07:55:51 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id d11-v6sor3041797wrr.38.2018.07.05.07.55.49 for (Google Transport Security); Thu, 05 Jul 2018 07:55:49 -0700 (PDT) From: osalvador@techadventures.net Subject: [PATCH] fs, elf: Make sure to page align bss in load_elf_library Date: Thu, 5 Jul 2018 16:55:39 +0200 Message-Id: <20180705145539.9627-1-osalvador@techadventures.net> Sender: owner-linux-mm@kvack.org List-ID: To: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, mhocko@suse.com, penguin-kernel@i-love.sakura.ne.jp, keescook@chromium.org, nicolas.pitre@linaro.org, Oscar Salvador From: Oscar Salvador The current code does not make sure to page align bss before calling vm_brk(), and this can lead to a VM_BUG_ON() in __mm_populate() due to the requested lenght not being correctly aligned. Let us make sure to align it properly. Signed-off-by: Oscar Salvador Tested-by: Tetsuo Handa Reported-by: syzbot+5dcb560fe12aa5091c06@syzkaller.appspotmail.com --- fs/binfmt_elf.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 0ac456b52bdd..816cc921cf36 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1259,9 +1259,8 @@ static int load_elf_library(struct file *file) goto out_free_ph; } - len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr + - ELF_MIN_ALIGN - 1); - bss = eppnt->p_memsz + eppnt->p_vaddr; + len = ELF_PAGEALIGN(eppnt->p_filesz + eppnt->p_vaddr); + bss = ELF_PAGEALIGN(eppnt->p_memsz + eppnt->p_vaddr); if (bss > len) { error = vm_brk(len, bss - len); if (error) -- 2.13.6