From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752637Ab2ILLht (ORCPT ); Wed, 12 Sep 2012 07:37:49 -0400 Received: from mail-ee0-f46.google.com ([74.125.83.46]:58993 "EHLO mail-ee0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751112Ab2ILLhs (ORCPT ); Wed, 12 Sep 2012 07:37:48 -0400 From: Denys Vlasenko To: Oleg Nesterov , linux-kernel@vger.kernel.org, Andrew Morton , Roland McGrath Cc: Denys Vlasenko Subject: [PATCH] coredump: prevent double-free on an error path in core dumper Date: Wed, 12 Sep 2012 13:37:25 +0200 Message-Id: <1347449845-23764-1-git-send-email-vda.linux@googlemail.com> X-Mailer: git-send-email 1.7.7.6 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- fs/binfmt_elf.c | 19 ++++--------------- 1 files changed, 4 insertions(+), 15 deletions(-) diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 760d7f5..1b4efbc 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1695,30 +1695,19 @@ static int elf_note_info_init(struct elf_note_info *info) 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, -- 1.7.7.6