From d3edaa91d4cf7202ec14342410194841e2f67f12 Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Fri, 26 Feb 2021 11:30:32 +1030 Subject: [PATCH v2] Reinstate various pieces backed out from smart_rename changes In the interests of a stable release various last minute smart_rename patches were backed out of the 2.36 branch. The main reason to reinstate some of those backed out changes here is to make necessary followup fixes to commit 8e03235147a9 simple cherry-picks from mainline. A secondary reason is that ar -M support isn't fixed for pr26945 without this patch. PR 26945 * ar.c: Don't include libbfd.h. (write_archive): Replace xmalloc+strcpy with xstrdup. * arsup.c (temp_name, real_ofd): New static variables. (ar_open): Use make_tempname and bfd_fdopenw. (ar_save): Adjust to suit ar_open changes. * objcopy.c: Don't include libbfd.h. * rename.c: Rename and reorder variables. (cherry picked from commit 95b91a043aeaeb546d2fea556d84a2de1e917770) Upstream-Status: Backport [https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=d3edaa91d4cf7202ec14342410194841e2f67f12] CVE: CVE-2021-20197 Signed-off-by: Vinay Kumar --- bfd/bfd-in2.h | 2 + bfd/opncls.c | 33 ++++++++++ binutils/ar.c | 15 +++-- binutils/arsup.c | 37 ++++++++---- binutils/bucomm.c | 4 +- binutils/bucomm.h | 5 +- binutils/objcopy.c | 37 +++++++----- binutils/rename.c | 148 +++++++++++---------------------------------- 8 files changed, 133 insertions(+), 148 deletions(-) diff --git a/bfd/bfd-in2.h b/bfd/bfd-in2.h index 2e453c50c18..e53f54a8ab7 100644 --- a/bfd/bfd-in2.h +++ b/bfd/bfd-in2.h @@ -588,6 +588,8 @@ bfd *bfd_openr (const char *filename, const char *target); bfd *bfd_fdopenr (const char *filename, const char *target, int fd); +bfd *bfd_fdopenw (const char *filename, const char *target, int fd); + bfd *bfd_openstreamr (const char * filename, const char * target, void * stream); diff --git a/bfd/opncls.c b/bfd/opncls.c index a03ad51c8fa..f9da97ed710 100644 --- a/bfd/opncls.c +++ b/bfd/opncls.c @@ -370,6 +370,39 @@ bfd_fdopenr (const char *filename, const char *target, int fd) return bfd_fopen (filename, target, mode, fd); } +/* +FUNCTION + bfd_fdopenw + +SYNOPSIS + bfd *bfd_fdopenw (const char *filename, const char *target, int fd); + +DESCRIPTION + <> is exactly like <> with the exception that + the resulting BFD is suitable for output. +*/ + +bfd * +bfd_fdopenw (const char *filename, const char *target, int fd) +{ + bfd *out = bfd_fdopenr (filename, target, fd); + + if (out != NULL) + { + if (!bfd_write_p (out)) + { + close (fd); + _bfd_delete_bfd (out); + out = NULL; + bfd_set_error (bfd_error_invalid_operation); + } + else + out->direction = write_direction; + } + + return out; +} + /* FUNCTION bfd_openstreamr diff --git a/binutils/ar.c b/binutils/ar.c index 1057db9980e..c33a11e0d70 100644 --- a/binutils/ar.c +++ b/binutils/ar.c @@ -1195,20 +1195,23 @@ write_archive (bfd *iarch) bfd *obfd; char *old_name, *new_name; bfd *contents_head = iarch->archive_next; + int ofd = -1; - old_name = (char *) xmalloc (strlen (bfd_get_filename (iarch)) + 1); - strcpy (old_name, bfd_get_filename (iarch)); - new_name = make_tempname (old_name); + old_name = xstrdup (bfd_get_filename (iarch)); + new_name = make_tempname (old_name, &ofd); if (new_name == NULL) bfd_fatal (_("could not create temporary file whilst writing archive")); output_filename = new_name; - obfd = bfd_openw (new_name, bfd_get_target (iarch)); + obfd = bfd_fdopenw (new_name, bfd_get_target (iarch), ofd); if (obfd == NULL) - bfd_fatal (old_name); + { + close (ofd); + bfd_fatal (old_name); + } output_bfd = obfd; @@ -1246,7 +1249,7 @@ write_archive (bfd *iarch) /* We don't care if this fails; we might be creating the archive. */ bfd_close (iarch); - if (smart_rename (new_name, old_name, 0) != 0) + if (smart_rename (new_name, old_name, NULL) != 0) xexit (1); free (old_name); free (new_name); diff --git a/binutils/arsup.c b/binutils/arsup.c index 00967c972cd..b8ae4f7ec1a 100644 --- a/binutils/arsup.c +++ b/binutils/arsup.c @@ -42,6 +42,8 @@ extern int deterministic; static bfd *obfd; static char *real_name; +static char *temp_name; +static int real_ofd; static FILE *outfile; static void @@ -149,27 +151,24 @@ maybequit (void) void ar_open (char *name, int t) { - char *tname; - const char *bname = lbasename (name); - real_name = name; + real_name = xstrdup (name); + temp_name = make_tempname (real_name, &real_ofd); - /* Prepend tmp- to the beginning, to avoid file-name clashes after - truncation on filesystems with limited namespaces (DOS). */ - if (asprintf (&tname, "%.*stmp-%s", (int) (bname - name), name, bname) == -1) + if (temp_name == NULL) { - fprintf (stderr, _("%s: Can't allocate memory for temp name (%s)\n"), + fprintf (stderr, _("%s: Can't open temporary file (%s)\n"), program_name, strerror(errno)); maybequit (); return; } - obfd = bfd_openw (tname, NULL); + obfd = bfd_fdopenw (temp_name, NULL, real_ofd); if (!obfd) { fprintf (stderr, _("%s: Can't open output archive %s\n"), - program_name, tname); + program_name, temp_name); maybequit (); } @@ -344,16 +343,30 @@ ar_save (void) } else { - char *ofilename = xstrdup (bfd_get_filename (obfd)); + struct stat target_stat; if (deterministic > 0) obfd->flags |= BFD_DETERMINISTIC_OUTPUT; bfd_close (obfd); - smart_rename (ofilename, real_name, 0); + if (stat (real_name, &target_stat) != 0) + { + /* The temp file created in ar_open has mode 0600 as per mkstemp. + Create the real empty output file here so smart_rename will + update the mode according to the process umask. */ + obfd = bfd_openw (real_name, NULL); + if (obfd != NULL) + { + bfd_set_format (obfd, bfd_archive); + bfd_close (obfd); + } + } + + smart_rename (temp_name, real_name, NULL); obfd = 0; - free (ofilename); + free (temp_name); + free (real_name); } } diff --git a/binutils/bucomm.c b/binutils/bucomm.c index 9e6a02843e6..53244201f89 100644 --- a/binutils/bucomm.c +++ b/binutils/bucomm.c @@ -532,7 +532,7 @@ template_in_dir (const char *path) as FILENAME. */ char * -make_tempname (const char *filename) +make_tempname (const char *filename, int *ofd) { char *tmpname = template_in_dir (filename); int fd; @@ -550,7 +550,7 @@ make_tempname (const char *filename) free (tmpname); return NULL; } - close (fd); + *ofd = fd; return tmpname; } diff --git a/binutils/bucomm.h b/binutils/bucomm.h index d8318343f78..2b164e0af68 100644 --- a/binutils/bucomm.h +++ b/binutils/bucomm.h @@ -51,7 +51,7 @@ int display_info (void); void print_arelt_descr (FILE *, bfd *, bfd_boolean, bfd_boolean); -char *make_tempname (const char *); +char *make_tempname (const char *, int *); char *make_tempdir (const char *); bfd_vma parse_vma (const char *, const char *); @@ -71,7 +71,8 @@ extern void print_version (const char *); /* In rename.c. */ extern void set_times (const char *, const struct stat *); -extern int smart_rename (const char *, const char *, int); +extern int smart_rename (const char *, const char *, struct stat *); + /* In libiberty. */ void *xmalloc (size_t); diff --git a/binutils/objcopy.c b/binutils/objcopy.c index 212e25144e6..5ccbd926610 100644 --- a/binutils/objcopy.c +++ b/binutils/objcopy.c @@ -3682,7 +3682,7 @@ set_long_section_mode (bfd *output_bfd, bfd *input_bfd, enum long_section_name_h /* The top-level control. */ static void -copy_file (const char *input_filename, const char *output_filename, +copy_file (const char *input_filename, const char *output_filename, int ofd, const char *input_target, const char *output_target, const bfd_arch_info_type *input_arch) { @@ -3757,9 +3757,14 @@ copy_file (const char *input_filename, const char *output_filename, else force_output_target = TRUE; - obfd = bfd_openw (output_filename, output_target); + if (ofd >= 0) + obfd = bfd_fdopenw (output_filename, output_target, ofd); + else + obfd = bfd_openw (output_filename, output_target); + if (obfd == NULL) { + close (ofd); bfd_nonfatal_message (output_filename, NULL, NULL, NULL); status = 1; return; @@ -3787,13 +3792,19 @@ copy_file (const char *input_filename, const char *output_filename, if (output_target == NULL) output_target = bfd_get_target (ibfd); - obfd = bfd_openw (output_filename, output_target); + if (ofd >= 0) + obfd = bfd_fdopenw (output_filename, output_target, ofd); + else + obfd = bfd_openw (output_filename, output_target); + if (obfd == NULL) { + close (ofd); bfd_nonfatal_message (output_filename, NULL, NULL, NULL); status = 1; return; } + /* This is a no-op on non-Coff targets. */ set_long_section_mode (obfd, ibfd, long_section_names); @@ -4746,6 +4757,7 @@ strip_main (int argc, char *argv[]) int hold_status = status; struct stat statbuf; char *tmpname; + int tmpfd = -1; if (get_file_size (argv[i]) < 1) { @@ -4760,7 +4772,7 @@ strip_main (int argc, char *argv[]) if (output_file == NULL || filename_cmp (argv[i], output_file) == 0) - tmpname = make_tempname (argv[i]); + tmpname = make_tempname (argv[i], &tmpfd); else tmpname = output_file; @@ -4773,15 +4785,13 @@ strip_main (int argc, char *argv[]) } status = 0; - copy_file (argv[i], tmpname, input_target, output_target, NULL); + copy_file (argv[i], tmpname, tmpfd, input_target, output_target, NULL); if (status == 0) { - if (preserve_dates) - set_times (tmpname, &statbuf); if (output_file != tmpname) status = (smart_rename (tmpname, output_file ? output_file : argv[i], - preserve_dates) != 0); + preserve_dates ? &statbuf : NULL) != 0); if (status == 0) status = hold_status; } @@ -4993,7 +5003,7 @@ copy_main (int argc, char *argv[]) bfd_boolean formats_info = FALSE; bfd_boolean use_globalize = FALSE; bfd_boolean use_keep_global = FALSE; - int c; + int c, tmpfd = -1; struct stat statbuf; const bfd_arch_info_type *input_arch = NULL; @@ -5839,7 +5849,7 @@ copy_main (int argc, char *argv[]) are the same, then create a temp and rename the result into the input. */ if (output_filename == NULL || filename_cmp (input_filename, output_filename) == 0) - tmpname = make_tempname (input_filename); + tmpname = make_tempname (input_filename, &tmpfd); else tmpname = output_filename; @@ -5847,14 +5857,13 @@ copy_main (int argc, char *argv[]) fatal (_("warning: could not create temporary file whilst copying '%s', (error: %s)"), input_filename, strerror (errno)); - copy_file (input_filename, tmpname, input_target, output_target, input_arch); + copy_file (input_filename, tmpname, tmpfd, input_target, output_target, + input_arch); if (status == 0) { - if (preserve_dates) - set_times (tmpname, &statbuf); if (tmpname != output_filename) status = (smart_rename (tmpname, input_filename, - preserve_dates) != 0); + preserve_dates ? &statbuf : NULL) != 0); } else unlink_if_ordinary (tmpname); diff --git a/binutils/rename.c b/binutils/rename.c index bf3b68d0462..07d44d0f314 100644 --- a/binutils/rename.c +++ b/binutils/rename.c @@ -24,14 +24,9 @@ #ifdef HAVE_GOOD_UTIME_H #include -#else /* ! HAVE_GOOD_UTIME_H */ -#ifdef HAVE_UTIMES +#elif defined HAVE_UTIMES #include -#endif /* HAVE_UTIMES */ -#endif /* ! HAVE_GOOD_UTIME_H */ - -#if ! defined (_WIN32) || defined (__CYGWIN32__) -static int simple_copy (const char *, const char *); +#endif /* The number of bytes to copy at once. */ #define COPY_BUF 8192 @@ -82,7 +77,6 @@ simple_copy (const char *from, const char *to) } return 0; } -#endif /* __CYGWIN32__ or not _WIN32 */ /* Set the times of the file DESTINATION to be the same as those in STATBUF. */ @@ -91,122 +85,52 @@ void set_times (const char *destination, const struct stat *statbuf) { int result; - - { #ifdef HAVE_GOOD_UTIME_H - struct utimbuf tb; - - tb.actime = statbuf->st_atime; - tb.modtime = statbuf->st_mtime; - result = utime (destination, &tb); -#else /* ! HAVE_GOOD_UTIME_H */ -#ifndef HAVE_UTIMES - long tb[2]; - - tb[0] = statbuf->st_atime; - tb[1] = statbuf->st_mtime; - result = utime (destination, tb); -#else /* HAVE_UTIMES */ - struct timeval tv[2]; - - tv[0].tv_sec = statbuf->st_atime; - tv[0].tv_usec = 0; - tv[1].tv_sec = statbuf->st_mtime; - tv[1].tv_usec = 0; - result = utimes (destination, tv); -#endif /* HAVE_UTIMES */ -#endif /* ! HAVE_GOOD_UTIME_H */ - } + struct utimbuf tb; + + tb.actime = statbuf->st_atime; + tb.modtime = statbuf->st_mtime; + result = utime (destination, &tb); +#elif defined HAVE_UTIMES + struct timeval tv[2]; + + tv[0].tv_sec = statbuf->st_atime; + tv[0].tv_usec = 0; + tv[1].tv_sec = statbuf->st_mtime; + tv[1].tv_usec = 0; + result = utimes (destination, tv); +#else + long tb[2]; + + tb[0] = statbuf->st_atime; + tb[1] = statbuf->st_mtime; + result = utime (destination, tb); +#endif if (result != 0) non_fatal (_("%s: cannot set time: %s"), destination, strerror (errno)); } -#ifndef S_ISLNK -#ifdef S_IFLNK -#define S_ISLNK(m) (((m) & S_IFMT) == S_IFLNK) -#else -#define S_ISLNK(m) 0 -#define lstat stat -#endif -#endif - -/* Rename FROM to TO, copying if TO is a link. - Return 0 if ok, -1 if error. */ +/* Copy FROM to TO. TARGET_STAT has the file status that, if non-NULL, + is used to fix up timestamps. Return 0 if ok, -1 if error. + At one time this function renamed files, but file permissions are + tricky to update given the number of different schemes used by + various systems. So now we just copy. */ int -smart_rename (const char *from, const char *to, int preserve_dates ATTRIBUTE_UNUSED) +smart_rename (const char *from, const char *to, + struct stat *target_stat) { - bfd_boolean exists; - struct stat s; - int ret = 0; - - exists = lstat (to, &s) == 0; - -#if defined (_WIN32) && !defined (__CYGWIN32__) - /* Win32, unlike unix, will not erase `to' in `rename(from, to)' but - fail instead. Also, chown is not present. */ + int ret; - if (exists) - remove (to); - - ret = rename (from, to); + ret = simple_copy (from, to); if (ret != 0) - { - /* We have to clean up here. */ - non_fatal (_("unable to rename '%s'; reason: %s"), to, strerror (errno)); - unlink (from); - } -#else - /* Use rename only if TO is not a symbolic link and has - only one hard link, and we have permission to write to it. */ - if (! exists - || (!S_ISLNK (s.st_mode) - && S_ISREG (s.st_mode) - && (s.st_mode & S_IWUSR) - && s.st_nlink == 1) - ) - { - ret = rename (from, to); - if (ret == 0) - { - if (exists) - { - /* Try to preserve the permission bits and ownership of - TO. First get the mode right except for the setuid - bit. Then change the ownership. Then fix the setuid - bit. We do the chmod before the chown because if the - chown succeeds, and we are a normal user, we won't be - able to do the chmod afterward. We don't bother to - fix the setuid bit first because that might introduce - a fleeting security problem, and because the chown - will clear the setuid bit anyhow. We only fix the - setuid bit if the chown succeeds, because we don't - want to introduce an unexpected setuid file owned by - the user running objcopy. */ - chmod (to, s.st_mode & 0777); - if (chown (to, s.st_uid, s.st_gid) >= 0) - chmod (to, s.st_mode & 07777); - } - } - else - { - /* We have to clean up here. */ - non_fatal (_("unable to rename '%s'; reason: %s"), to, strerror (errno)); - unlink (from); - } - } - else - { - ret = simple_copy (from, to); - if (ret != 0) - non_fatal (_("unable to copy file '%s'; reason: %s"), to, strerror (errno)); + non_fatal (_("unable to copy file '%s'; reason: %s"), + to, strerror (errno)); - if (preserve_dates) - set_times (to, &s); - unlink (from); - } -#endif /* _WIN32 && !__CYGWIN32__ */ + if (target_stat != NULL) + set_times (to, target_stat); + unlink (from); return ret; } -- 2.17.1