From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752138Ab3FDX0k (ORCPT ); Tue, 4 Jun 2013 19:26:40 -0400 Received: from 1wt.eu ([62.212.114.60]:35184 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751862Ab3FDWky (ORCPT ); Tue, 4 Jun 2013 18:40:54 -0400 Message-Id: <20130604172131.347714149@1wt.eu> User-Agent: quilt/0.48-1 Date: Tue, 04 Jun 2013 19:21:55 +0200 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Oleg Nesterov , Denys Vlasenko , Venu Byravarasu , Andrew Morton , Greg Kroah-Hartman , Willy Tarreau Subject: [ 025/184] coredump: prevent double-free on an error path in In-Reply-To: <58df134a4b98edf5b0073e2e1e988fe6@local> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ core dumper 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 Signed-off-by: Willy Tarreau --- fs/binfmt_elf.c | 19 ++++--------------- 1 file changed, 4 insertions(+), 15 deletions(-) diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index a64fde6..c564293 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1699,30 +1699,19 @@ 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, -- 1.7.12.2.21.g234cd45.dirty