From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752271AbaLPQ7K (ORCPT ); Tue, 16 Dec 2014 11:59:10 -0500 Received: from mail.kernel.org ([198.145.19.201]:47194 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752250AbaLPQ7H (ORCPT ); Tue, 16 Dec 2014 11:59:07 -0500 From: Arnaldo Carvalho de Melo To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Mitchell Krome , Jiri Olsa , Ingo Molnar , Jiri Olsa , Paul Mackerras , Peter Zijlstra , Arnaldo Carvalho de Melo Subject: [PATCH 18/18] perf symbols: Fix use after free in filename__read_build_id Date: Tue, 16 Dec 2014 13:57:20 -0300 Message-Id: <1418749040-31807-19-git-send-email-acme@kernel.org> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1418749040-31807-1-git-send-email-acme@kernel.org> References: <1418749040-31807-1-git-send-email-acme@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mitchell Krome In filename__read_build_id, phdr points to memory in buf, which gets realloced before a call to fseek that uses phdr->p_offset. This change stores the value of p_offset before buf is realloced, so the fseek can use the value safely. Signed-off-by: Mitchell Krome Cc: Jiri Olsa Cc: Ingo Molnar Cc: Jiri Olsa Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20141216021612.GA7199@mitchell Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/symbol-minimal.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/symbol-minimal.c b/tools/perf/util/symbol-minimal.c index fa585c63f56a..d7efb03b3f9a 100644 --- a/tools/perf/util/symbol-minimal.c +++ b/tools/perf/util/symbol-minimal.c @@ -129,6 +129,7 @@ int filename__read_build_id(const char *filename, void *bf, size_t size) for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) { void *tmp; + long offset; if (need_swap) { phdr->p_type = bswap_32(phdr->p_type); @@ -140,12 +141,13 @@ int filename__read_build_id(const char *filename, void *bf, size_t size) continue; buf_size = phdr->p_filesz; + offset = phdr->p_offset; tmp = realloc(buf, buf_size); if (tmp == NULL) goto out_free; buf = tmp; - fseek(fp, phdr->p_offset, SEEK_SET); + fseek(fp, offset, SEEK_SET); if (fread(buf, buf_size, 1, fp) != 1) goto out_free; @@ -178,6 +180,7 @@ int filename__read_build_id(const char *filename, void *bf, size_t size) for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) { void *tmp; + long offset; if (need_swap) { phdr->p_type = bswap_32(phdr->p_type); @@ -189,12 +192,13 @@ int filename__read_build_id(const char *filename, void *bf, size_t size) continue; buf_size = phdr->p_filesz; + offset = phdr->p_offset; tmp = realloc(buf, buf_size); if (tmp == NULL) goto out_free; buf = tmp; - fseek(fp, phdr->p_offset, SEEK_SET); + fseek(fp, offset, SEEK_SET); if (fread(buf, buf_size, 1, fp) != 1) goto out_free; -- 1.9.3