Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754966Ab2JNO5Z (ORCPT ); Sun, 14 Oct 2012 10:57:25 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:46533 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754554Ab2JNOn2 (ORCPT ); Sun, 14 Oct 2012 10:43:28 -0400 Message-Id: <20121014143543.169892076@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Sun, 14 Oct 2012 15:36:42 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Denys Vlasenko , Oleg Nesterov , Venu Byravarasu Subject: [ 069/147] coredump: prevent double-free on an error path in core dumper In-Reply-To: <20121014143533.742627615@decadent.org.uk> X-SA-Exim-Connect-IP: 77.75.106.1 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2161 Lines: 72 3.2-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: Ben Hutchings --- 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 1b52956..0225fdd 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1696,30 +1696,19 @@ 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, -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/