From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-x52c.google.com (mail-pg1-x52c.google.com [IPv6:2607:f8b0:4864:20::52c]) by sourceware.org (Postfix) with ESMTPS id 982D13894E77; Tue, 19 May 2020 04:32:11 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 982D13894E77 Received: by mail-pg1-x52c.google.com with SMTP id r22so5813889pga.12; Mon, 18 May 2020 21:32:11 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:subject:message-id:mime-version :content-disposition:user-agent; bh=oAo9iM19Re3aqmjScr1jNOvIar4eXvIeZnip5igvCaY=; b=kdmSK4dBmDZtoGjCGQ1xGsYYFXR5MCqo/f6b8jnuecCDiiW3ruvXOuz/AL0G5kGLMZ B2D8NnRdeadSwouoKXGvYSv6DoVN5pKDp2HL9UsPrH7fi8LNzVORzdVDMZ8kFdcUIyLq TBlY7hUzoy34qBxQ63Rospydt+7Wwn4z5YvMtUrPrBp/jDK7nmHMnObjS0HgjvqE89ws TtNc7MdqyCAMUWQSBUY0REl7d3XXrHY6pV7+ENtWUS7yWH3fiRuzFeLL9475mSDFoJ1I xsvfDINHP4U7G5P9RqWDBQjANPxXRBSbXDQ//S4KVTUwjOMeAqcs/qPk/jKfsNSKxPtq bgnQ== X-Gm-Message-State: AOAM530W/sxRPgpwmzB9FUgBwp2aM7K1vbYkLFUTNyIAeqfa+HXZLJT4 +WOyyJFrhPxGY9zZfpwT5NxIZeoRLy4= X-Google-Smtp-Source: ABdhPJwgo0YSBQgnDJmsTgetgqJuFICiICFGa/pgFq3vOhuWWTdFiKygDNL6yI2lcaKXvAV9tdSPoA== X-Received: by 2002:a62:ed02:: with SMTP id u2mr20666102pfh.60.1589862729848; Mon, 18 May 2020 21:32:09 -0700 (PDT) Received: from bubble.grove.modra.org ([2406:3400:51d:8cc0:740f:4bb6:e826:f1d0]) by smtp.gmail.com with ESMTPSA id 189sm9896729pfd.55.2020.05.18.21.32.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 May 2020 21:32:09 -0700 (PDT) Received: by bubble.grove.modra.org (Postfix, from userid 1000) id 381B880DF4; Tue, 19 May 2020 14:02:05 +0930 (ACST) Date: Tue, 19 May 2020 14:02:05 +0930 From: Alan Modra To: binutils@sourceware.org, gdb-patches@sourceware.org Subject: PR25993, read of freed memory Message-ID: <20200519043205.GT1088@bubble.grove.modra.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) X-Spam-Status: No, score=-10.3 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 19 May 2020 04:32:13 -0000 ldmain.c:add_archive_element copies file name pointers from the bfd to a lang_input_statement_type. input->filename = abfd->filename; input->local_sym_name = abfd->filename; This results in stale pointers when twiddling the bfd filename in places like the pe ld after_open. So don't free the bfd filename, and make copies using bfd_alloc memory that won't result in small memory leaks that annoy memory checkers. The patch that has already been applied for PR25993 can leave local_sym_name dangling into freed memory, and I think it might even be possible for ldlang.c:lookup_name to read this memory. Since this patch touches gdb files, OK to apply there after the 9.2 release? Note that I don't properly handle a NULL return from bfd_set_filename (out of memory condition). I went looking to see what xstrprintf does, and found gdb gives an internal_error. Really?? PR 25993 bfd/ * archive.c (_bfd_get_elt_at_filepos): Don't strdup filename, use bfd_set_filename. * elfcode.h (_bfd_elf_bfd_from_remote_memory): Likewise. * mach-o.c (bfd_mach_o_fat_member_init): Likewise. * opncls.c (bfd_fopen, bfd_openstreamr, bfd_openr_iovec, bfd_openw), (bfd_create): Likewise. (_bfd_delete_bfd): Don't free filename. (bfd_set_filename): Copy filename param to bfd_alloc'd memory, return pointer to the copy or NULL on alloc fail. * vms-lib.c (_bfd_vms_lib_get_module): Free newname and test result of bfd_set_filename. * bfd-in2.h: Regenerate. gdb/ * solib-darwin.c (darwin_bfd_open): Don't strdup pathname for bfd_set_filename. * solib-aix.c (solib_aix_bfd_open): Free name after calling bfd_set_filename. * symfile-mem.c (symbol_file_add_from_memory): Likewise. ld/ * emultempl/pe.em (gld_${EMULATION_NAME}_after_open): Don't copy other_bfd_filename for bfd_set_filename, and test result of bfd_set_filename call. Don't create a new is->filename, simply copy from bfd filename. Free new_name after bfd_set_filename. * emultempl/pep.em (gld_${EMULATION_NAME}_after_open): Likewise. diff --git a/bfd/archive.c b/bfd/archive.c index ff64727c44..1322977744 100644 --- a/bfd/archive.c +++ b/bfd/archive.c @@ -737,8 +737,7 @@ _bfd_get_elt_at_filepos (bfd *archive, file_ptr filepos) else { n_bfd->origin = n_bfd->proxy_origin; - n_bfd->filename = bfd_strdup (filename); - if (n_bfd->filename == NULL) + if (!bfd_set_filename (n_bfd, filename)) goto out; } diff --git a/bfd/bfd-in2.h b/bfd/bfd-in2.h index ec23fd4987..44bca15d5a 100644 --- a/bfd/bfd-in2.h +++ b/bfd/bfd-in2.h @@ -643,7 +643,7 @@ bfd_boolean bfd_fill_in_gnu_debuglink_section char *bfd_follow_build_id_debuglink (bfd *abfd, const char *dir); -void bfd_set_filename (bfd *abfd, char *filename); +char *bfd_set_filename (bfd *abfd, const char *filename); /* Extracted from libbfd.c. */ diff --git a/bfd/elfcode.h b/bfd/elfcode.h index 68db3e9ee3..5e6b2a430f 100644 --- a/bfd/elfcode.h +++ b/bfd/elfcode.h @@ -1680,7 +1680,6 @@ NAME(_bfd_elf,bfd_from_remote_memory) bfd_vma high_offset; bfd_vma shdr_end; bfd_vma loadbase; /* Bytes. */ - char *filename; size_t amt; unsigned int opb = bfd_octets_per_byte (templ, NULL); @@ -1894,22 +1893,14 @@ NAME(_bfd_elf,bfd_from_remote_memory) free (contents); return NULL; } - filename = bfd_strdup (""); - if (filename == NULL) - { - free (bim); - free (contents); - return NULL; - } nbfd = _bfd_new_bfd (); - if (nbfd == NULL) + if (nbfd == NULL + || !bfd_set_filename (nbfd, "")) { - free (filename); free (bim); free (contents); return NULL; } - nbfd->filename = filename; nbfd->xvec = templ->xvec; bim->size = high_offset; bim->buffer = contents; diff --git a/bfd/mach-o.c b/bfd/mach-o.c index 33bd81e121..ee8c6154b7 100644 --- a/bfd/mach-o.c +++ b/bfd/mach-o.c @@ -5578,21 +5578,18 @@ bfd_mach_o_fat_member_init (bfd *abfd, if (ap) { /* Use the architecture name if known. */ - filename = bfd_strdup (ap->printable_name); - if (filename == NULL) - return FALSE; + filename = bfd_set_filename (abfd, ap->printable_name); } else { /* Forge a uniq id. */ - const size_t namelen = 2 + 8 + 1 + 2 + 8 + 1; - filename = bfd_malloc (namelen); - if (filename == NULL) - return FALSE; - snprintf (filename, namelen, "0x%lx-0x%lx", + char buf[2 + 8 + 1 + 2 + 8 + 1]; + snprintf (buf, sizeof (buf), "0x%lx-0x%lx", entry->cputype, entry->cpusubtype); + filename = bfd_set_filename (abfd, buf); } - bfd_set_filename (abfd, filename); + if (!filename) + return FALSE; areltdata = bfd_zmalloc (sizeof (struct areltdata)); if (areltdata == NULL) diff --git a/bfd/opncls.c b/bfd/opncls.c index 5d3437d382..6c2bec4520 100644 --- a/bfd/opncls.c +++ b/bfd/opncls.c @@ -126,7 +126,6 @@ _bfd_delete_bfd (bfd *abfd) objalloc_free ((struct objalloc *) abfd->memory); } - free ((char *) bfd_get_filename (abfd)); free (abfd->arelt_data); free (abfd); } @@ -232,8 +231,7 @@ bfd_fopen (const char *filename, const char *target, const char *mode, int fd) /* PR 11983: Do not cache the original filename, but rather make a copy - the original might go away. */ - nbfd->filename = bfd_strdup (filename); - if (nbfd->filename == NULL) + if (!bfd_set_filename (nbfd, filename)) { fclose (nbfd->iostream); _bfd_delete_bfd (nbfd); @@ -406,8 +404,7 @@ bfd_openstreamr (const char *filename, const char *target, void *streamarg) nbfd->iostream = stream; /* PR 11983: Do not cache the original filename, but rather make a copy - the original might go away. */ - nbfd->filename = bfd_strdup (filename); - if (nbfd->filename == NULL) + if (!bfd_set_filename (nbfd, filename)) { _bfd_delete_bfd (nbfd); return NULL; @@ -607,8 +604,7 @@ bfd_openr_iovec (const char *filename, const char *target, /* PR 11983: Do not cache the original filename, but rather make a copy - the original might go away. */ - nbfd->filename = bfd_strdup (filename); - if (nbfd->filename == NULL) + if (!bfd_set_filename (nbfd, filename)) { _bfd_delete_bfd (nbfd); return NULL; @@ -679,8 +675,7 @@ bfd_openw (const char *filename, const char *target) /* PR 11983: Do not cache the original filename, but rather make a copy - the original might go away. */ - nbfd->filename = bfd_strdup (filename); - if (nbfd->filename == NULL) + if (!bfd_set_filename (nbfd, filename)) { _bfd_delete_bfd (nbfd); return NULL; @@ -824,8 +819,7 @@ bfd_create (const char *filename, bfd *templ) return NULL; /* PR 11983: Do not cache the original filename, but rather make a copy - the original might go away. */ - nbfd->filename = bfd_strdup (filename); - if (nbfd->filename == NULL) + if (!bfd_set_filename (nbfd, filename)) { _bfd_delete_bfd (nbfd); return NULL; @@ -2040,17 +2034,23 @@ FUNCTION bfd_set_filename SYNOPSIS - void bfd_set_filename (bfd *abfd, char *filename); + char *bfd_set_filename (bfd *abfd, const char *filename); DESCRIPTION - Set the filename of @var{abfd}. The old filename, if any, is freed. - @var{filename} must be allocated using @code{xmalloc}. After - this call, it is owned @var{abfd}. + Set the filename of @var{abfd}, copying the FILENAME parameter to + bfd_alloc'd memory owned by @var{abfd}. Returns a pointer the + newly allocated name, or NULL if the allocation failed. */ -void -bfd_set_filename (bfd *abfd, char *filename) +char * +bfd_set_filename (bfd *abfd, const char *filename) { - free ((char *) abfd->filename); - abfd->filename = filename; + size_t len = strlen (filename) + 1; + char *n = bfd_alloc (abfd, len); + if (n) + { + memcpy (n, filename, len); + abfd->filename = n; + } + return n; } diff --git a/bfd/vms-lib.c b/bfd/vms-lib.c index 9504cf4976..6a8a76ecb0 100644 --- a/bfd/vms-lib.c +++ b/bfd/vms-lib.c @@ -1452,6 +1452,12 @@ _bfd_vms_lib_get_module (bfd *abfd, unsigned int modidx) break; } bfd_set_filename (res, newname); + free (newname); + if (bfd_get_filename (res) == NULL) + { + bfd_close (res); + return NULL; + } tdata->cache[modidx] = res; diff --git a/gdb/solib-aix.c b/gdb/solib-aix.c index 5da1214a25..ddb14fa81d 100644 --- a/gdb/solib-aix.c +++ b/gdb/solib-aix.c @@ -637,10 +637,11 @@ solib_aix_bfd_open (const char *pathname) along with appended parenthesized member name in order to allow commands listing all shared libraries to display. Otherwise, we would only be displaying the name of the archive member object. */ - bfd_set_filename (object_bfd.get (), - xstrprintf ("%s%s", - bfd_get_filename (archive_bfd.get ()), - sep)); + char *fname = xstrprintf ("%s%s", + bfd_get_filename (archive_bfd.get ()), + sep); + bfd_set_filename (object_bfd.get (), fname); + free (fname); return object_bfd; } diff --git a/gdb/solib-darwin.c b/gdb/solib-darwin.c index 03d91d1690..498d6e2073 100644 --- a/gdb/solib-darwin.c +++ b/gdb/solib-darwin.c @@ -662,7 +662,7 @@ darwin_bfd_open (const char *pathname) /* The current filename for fat-binary BFDs is a name generated by BFD, usually a string containing the name of the architecture. Reset its value to the actual filename. */ - bfd_set_filename (res.get (), xstrdup (pathname)); + bfd_set_filename (res.get (), pathname); return res; } diff --git a/gdb/symfile-mem.c b/gdb/symfile-mem.c index e2d2e43d7f..18de07fd1c 100644 --- a/gdb/symfile-mem.c +++ b/gdb/symfile-mem.c @@ -78,8 +78,7 @@ target_read_memory_bfd (bfd_vma memaddr, bfd_byte *myaddr, bfd_size_type len) and read its in-core symbols out of inferior memory. SIZE, if non-zero, is the known size of the object. TEMPL is a bfd representing the target's format. NAME is the name to use for this - symbol file in messages; it can be NULL or a malloc-allocated string - which will be attached to the BFD. */ + symbol file in messages; it can be NULL or a malloc-allocated string. */ static struct objfile * symbol_file_add_from_memory (struct bfd *templ, CORE_ADDR addr, size_t size, char *name, int from_tty) @@ -104,6 +103,7 @@ symbol_file_add_from_memory (struct bfd *templ, CORE_ADDR addr, if (name == NULL) name = xstrdup ("shared object read from target memory"); bfd_set_filename (nbfd, name); + free (name); if (!bfd_check_format (nbfd, bfd_object)) error (_("Got object file from memory but can't read symbols: %s."), diff --git a/ld/emultempl/pe.em b/ld/emultempl/pe.em index fe65d2b266..8c5ee76233 100644 --- a/ld/emultempl/pe.em +++ b/ld/emultempl/pe.em @@ -1523,7 +1523,6 @@ gld_${EMULATION_NAME}_after_open (void) struct bfd_symbol *s; struct bfd_link_hash_entry * blhe; const char *other_bfd_filename; - char *n; s = (relocs[i]->sym_ptr_ptr)[0]; @@ -1550,9 +1549,9 @@ gld_${EMULATION_NAME}_after_open (void) continue; /* Rename this implib to match the other one. */ - n = xmalloc (strlen (other_bfd_filename) + 1); - strcpy (n, other_bfd_filename); - bfd_set_filename (is->the_bfd->my_archive, n); + if (!bfd_set_filename (is->the_bfd->my_archive, + other_bfd_filename)) + einfo ("%F%P: %pB: %E\n", is->the_bfd); } free (relocs); @@ -1655,28 +1654,14 @@ gld_${EMULATION_NAME}_after_open (void) else /* sentinel */ seq = 'c'; - /* PR 25993: It is possible that is->the_bfd-filename == is->filename. - In which case calling bfd_set_filename on one will free the memory - pointed to by the other. */ - if (is->filename == bfd_get_filename (is->the_bfd)) - { - new_name = xmalloc (strlen (is->filename) + 3); - sprintf (new_name, "%s.%c", is->filename, seq); - bfd_set_filename (is->the_bfd, new_name); - is->filename = new_name; - } - else - { - new_name - = xmalloc (strlen (bfd_get_filename (is->the_bfd)) + 3); - sprintf (new_name, "%s.%c", - bfd_get_filename (is->the_bfd), seq); - bfd_set_filename (is->the_bfd, new_name); - - new_name = xmalloc (strlen (is->filename) + 3); - sprintf (new_name, "%s.%c", is->filename, seq); - is->filename = new_name; - } + new_name + = xmalloc (strlen (bfd_get_filename (is->the_bfd)) + 3); + sprintf (new_name, "%s.%c", + bfd_get_filename (is->the_bfd), seq); + is->filename = bfd_set_filename (is->the_bfd, new_name); + free (new_name); + if (!is->filename) + einfo ("%F%P: %pB: %E\n", is->the_bfd); } } } diff --git a/ld/emultempl/pep.em b/ld/emultempl/pep.em index 699b86501c..ea8e768ea9 100644 --- a/ld/emultempl/pep.em +++ b/ld/emultempl/pep.em @@ -1491,7 +1491,6 @@ gld_${EMULATION_NAME}_after_open (void) struct bfd_symbol *s; struct bfd_link_hash_entry * blhe; const char *other_bfd_filename; - char *n; s = (relocs[i]->sym_ptr_ptr)[0]; @@ -1518,9 +1517,9 @@ gld_${EMULATION_NAME}_after_open (void) continue; /* Rename this implib to match the other one. */ - n = xmalloc (strlen (other_bfd_filename) + 1); - strcpy (n, other_bfd_filename); - bfd_set_filename (is->the_bfd->my_archive, n); + if (!bfd_set_filename (is->the_bfd->my_archive, + other_bfd_filename)) + einfo ("%F%P: %pB: %E\n", is->the_bfd); } free (relocs); @@ -1623,28 +1622,14 @@ gld_${EMULATION_NAME}_after_open (void) else /* sentinel */ seq = 'c'; - /* PR 25993: It is possible that is->the_bfd-filename == is->filename. - In which case calling bfd_set_filename on one will free the memory - pointed to by the other. */ - if (is->filename == bfd_get_filename (is->the_bfd)) - { - new_name = xmalloc (strlen (is->filename) + 3); - sprintf (new_name, "%s.%c", is->filename, seq); - bfd_set_filename (is->the_bfd, new_name); - is->filename = new_name; - } - else - { - new_name - = xmalloc (strlen (bfd_get_filename (is->the_bfd)) + 3); - sprintf (new_name, "%s.%c", - bfd_get_filename (is->the_bfd), seq); - bfd_set_filename (is->the_bfd, new_name); - - new_name = xmalloc (strlen (is->filename) + 3); - sprintf (new_name, "%s.%c", is->filename, seq); - is->filename = new_name; - } + new_name + = xmalloc (strlen (bfd_get_filename (is->the_bfd)) + 3); + sprintf (new_name, "%s.%c", + bfd_get_filename (is->the_bfd), seq); + is->filename = bfd_set_filename (is->the_bfd, new_name); + free (new_name); + if (!is->filename) + einfo ("%F%P: %pB: %E\n", is->the_bfd); } } } -- Alan Modra Australia Development Lab, IBM