From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 58456 invoked by alias); 17 Oct 2017 14:44:00 -0000 Mailing-List: contact gdb-testers-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-testers-owner@sourceware.org Received: (qmail 58397 invoked by uid 89); 17 Oct 2017 14:43:59 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.0 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD,SPF_PASS autolearn=ham version=3.3.2 spammy= X-HELO: kwanyin.sergiodj.net Received: from kwanyin.sergiodj.net (HELO kwanyin.sergiodj.net) (158.69.185.54) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Tue, 17 Oct 2017 14:43:58 +0000 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [binutils-gdb] Fix double-free corruption From: sergiodj+buildbot@sergiodj.net To: gdb-testers@sourceware.org Message-Id: <7b7009999ab8daac9db776c850b7df6e1f586334@gdb-build> Date: Tue, 17 Oct 2017 14:44:00 -0000 X-SW-Source: 2017-q4/txt/msg02099.txt.bz2 *** TEST RESULTS FOR COMMIT 7b7009999ab8daac9db776c850b7df6e1f586334 *** Author: Pedro Alves Branch: master Commit: 7b7009999ab8daac9db776c850b7df6e1f586334 Fix double-free corruption Fixes a double-free regression introduced by commit b7b030adc405 ("Return unique_xmalloc_ptr from target_read_stralloc"): gdb.sum: Running src/gdb/testsuite/gdb.base/catch-syscall.exp ... ERROR: Process no longer exists Valgrind shows: (gdb) catch syscall ==3687== Thread 1: ==3687== Invalid free() / delete / delete[] / realloc() ==3687== at 0x4C29CF0: free (vg_replace_malloc.c:530) ==3687== by 0x610862: xfree(void*) (common-utils.c:101) ==3687== by 0x440D5D: gdb::xfree_deleter::operator()(char*) const (gdb_unique_ptr.h:34) ==3687== by 0x446CC6: std::unique_ptr >::reset(char*) (unique_ptr.h:344) ==3687== by 0x81BE50: xml_fetch_content_from_file(char const*, void*) (xml-support.c:1042) ==3687== by 0x81DA86: xml_init_syscalls_info(char const*) (xml-syscall.c:366) ==3687== by 0x81DBDD: init_syscalls_info(gdbarch*) (xml-syscall.c:398) ==3687== by 0x81E131: get_syscall_by_number(gdbarch*, int, syscall*) (xml-syscall.c:599) ==3687== by 0x5BE86F: catch_syscall_command_1(char*, int, cmd_list_element*) (break-catch-syscall.c:481) ==3687== by 0x4B46B1: do_sfunc(cmd_list_element*, char*, int) (cli-decode.c:138) ==3687== by 0x4B76B8: cmd_func(cmd_list_element*, char*, int) (cli-decode.c:1952) ==3687== by 0x7E91C7: execute_command(char*, int) (top.c:615) ==3687== Address 0x14332ae0 is 0 bytes inside a block of size 4,096 free'd ==3687== at 0x4C2AB8B: realloc (vg_replace_malloc.c:785) ==3687== by 0x610792: xrealloc (common-utils.c:62) ==3687== by 0x81BE3E: xml_fetch_content_from_file(char const*, void*) (xml-support.c:1042) ==3687== by 0x81DA86: xml_init_syscalls_info(char const*) (xml-syscall.c:366) ==3687== by 0x81DBDD: init_syscalls_info(gdbarch*) (xml-syscall.c:398) ==3687== by 0x81E131: get_syscall_by_number(gdbarch*, int, syscall*) (xml-syscall.c:599) ==3687== by 0x5BE86F: catch_syscall_command_1(char*, int, cmd_list_element*) (break-catch-syscall.c:481) ==3687== by 0x4B46B1: do_sfunc(cmd_list_element*, char*, int) (cli-decode.c:138) ==3687== by 0x4B76B8: cmd_func(cmd_list_element*, char*, int) (cli-decode.c:1952) ==3687== by 0x7E91C7: execute_command(char*, int) (top.c:615) ==3687== by 0x6A422D: command_handler(char*) (event-top.c:583) ==3687== by 0x6A45F2: command_line_handler(char*) (event-top.c:773) [...] The problem is that if xrealloc decides it needs a new memory block, it frees the previous block/pointer, and then text.reset() frees it again. gdb/ChangeLog: 2017-10-17 Pedro Alves * xml-support.c (xml_fetch_content_from_file): Call unique_ptr::release() instead unique_ptr::get() when passing through xrealloc.