From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933939Ab2JDVWW (ORCPT ); Thu, 4 Oct 2012 17:22:22 -0400 Received: from mail-da0-f46.google.com ([209.85.210.46]:50177 "EHLO mail-da0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933917Ab2JDVWJ (ORCPT ); Thu, 4 Oct 2012 17:22:09 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Oleg Nesterov , Denys Vlasenko , Venu Byravarasu , Andrew Morton Subject: [ 39/58] coredump: prevent double-free on an error path in core dumper Date: Thu, 4 Oct 2012 14:19:46 -0700 Message-Id: <20121004210640.358992826@linuxfoundation.org> X-Mailer: git-send-email 1.7.12.2.421.g261b511 In-Reply-To: <20121004210635.449598766@linuxfoundation.org> References: <20121004210635.449598766@linuxfoundation.org> User-Agent: quilt/0.60-2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Denys Vlasenko commit f34f9d186df35e5c39163444c43b4fc6255e39c5 upstream. In !CORE_DUMP_USE_REGSET case, if elf_note_info_init fails to allocate memory for info->fields, it frees already allocated stuff and returns error to its caller, fill_note_info. Which in turn returns error to its caller, elf_core_dump. Which jumps to cleanup label and calls free_note_info, which will happily try to free all info->fields again. BOOM. This is the fix. Signed-off-by: Oleg Nesterov Signed-off-by: Denys Vlasenko Cc: Venu Byravarasu Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- fs/binfmt_elf.c | 19 ++++--------------- 1 file changed, 4 insertions(+), 15 deletions(-) --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1696,30 +1696,19 @@ static int elf_note_info_init(struct elf return 0; info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL); if (!info->psinfo) - goto notes_free; + return 0; info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL); if (!info->prstatus) - goto psinfo_free; + return 0; info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL); if (!info->fpu) - goto prstatus_free; + return 0; #ifdef ELF_CORE_COPY_XFPREGS info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL); if (!info->xfpu) - goto fpu_free; + return 0; #endif return 1; -#ifdef ELF_CORE_COPY_XFPREGS - fpu_free: - kfree(info->fpu); -#endif - prstatus_free: - kfree(info->prstatus); - psinfo_free: - kfree(info->psinfo); - notes_free: - kfree(info->notes); - return 0; } static int fill_note_info(struct elfhdr *elf, int phdrs,