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-rw-r--r--elf/Makefile13
-rw-r--r--elf/dl-error.c33
-rw-r--r--elf/dl-load.c70
-rw-r--r--elf/ldd.bash.in58
-rw-r--r--elf/ldd.sh.in54
-rw-r--r--elf/link.h20
-rw-r--r--elf/rtld.c124
7 files changed, 297 insertions, 75 deletions
diff --git a/elf/Makefile b/elf/Makefile
index 8f98cb8406..87f2d0d67d 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -41,6 +41,8 @@ extra-libs = libdl
extra-libs-others = $(extra-libs)
libdl-routines := dlopen dlclose dlsym dlerror dladdr
+before-compile = $(objpfx)trusted-dirs.h
+
all: # Make this the default target; it will be defined in Rules.
@@ -92,6 +94,17 @@ $(objpfx)$(rtld-installed-name): $(objpfx)ld.so
ln -s $(<F) $@
endif
+# Build a file mentioning all trustworthy directories to look for shared
+# libraries when using LD_LIBRARY_PATH in a setuid program. The user can
+# add directories to the list by defining $(user-defined-trusted-dirs)
+# before starting make.
+$(objpfx)trusted-dirs.h: Makefile
+ (for dir in `echo "$(default-rpath) $(user-defined-trusted-dirs)" | \
+ sed 's/:/ /g'`; do \
+ echo " \"$$dir\","; \
+ done;) > $@T
+ mv -f $@T $@
+CFLAGS-dl-load.c = -I$(objdir)/$(subdir)
# Specify the dependencies of libdl.so; its commands come from the generic
# rule to build a shared library.
diff --git a/elf/dl-error.c b/elf/dl-error.c
index 52eb577eb0..a19ccff626 100644
--- a/elf/dl-error.c
+++ b/elf/dl-error.c
@@ -37,6 +37,11 @@ struct catch
this is null. */
static struct catch *catch;
+/* This points to a function which is called when an error is
+ received. Unlike the handling of `catch' this function may return.
+ The arguments will be the `errstring' and `objname'. */
+static receiver_fct receiver;
+
void
_dl_signal_error (int errcode,
@@ -58,6 +63,13 @@ _dl_signal_error (int errcode,
catch->objname = objname;
longjmp (catch->env, errcode ?: -1);
}
+ else if (receiver)
+ {
+ /* We are inside _dl_receive_error. Call the user supplied
+ handler and resume the work. The receiver will still
+ installed. */
+ (*receiver) (errstring, objname);
+ }
else
{
/* Lossage while resolving the program's own symbols is always fatal. */
@@ -77,6 +89,8 @@ _dl_catch_error (char **errstring,
{
int errcode;
struct catch *old, c = { errstring: NULL, objname: NULL };
+ /* We need not handle `receiver' since setting a `catch' is handle
+ before it. */
old = catch;
errcode = setjmp (c.env);
@@ -96,3 +110,22 @@ _dl_catch_error (char **errstring,
*objname = c.objname;
return errcode == -1 ? 0 : errcode;
}
+
+void
+_dl_receive_error (receiver_fct fct, void (*operate) (void))
+{
+ struct catch *old_catch;
+ receiver_fct old_receiver;
+
+ old_catch = catch;
+ old_receiver = receiver;
+
+ /* Set the new values. */
+ catch = NULL;
+ receiver = fct;
+
+ (*operate) ();
+
+ catch = old_catch;
+ receiver = old_receiver;
+}
diff --git a/elf/dl-load.c b/elf/dl-load.c
index 7dc6d91a02..6a3d919976 100644
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@@ -1,5 +1,5 @@
/* _dl_map_object -- Map in a shared object's segments from the file.
- Copyright (C) 1995, 1996 Free Software Foundation, Inc.
+ Copyright (C) 1995, 1996, 1997 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
@@ -409,7 +409,8 @@ _dl_map_object_from_fd (char *name, int fd, char *realname,
static int
open_path (const char *name, size_t namelen,
const char *dirpath,
- char **realname)
+ char **realname,
+ const char *trusted_dirs[])
{
char *buf;
const char *p;
@@ -426,13 +427,42 @@ open_path (const char *name, size_t namelen,
do
{
size_t buflen;
+ size_t this_len;
dirpath = p;
p = strpbrk (dirpath, ":;");
if (p == NULL)
p = strchr (dirpath, '\0');
- if (p == dirpath)
+ this_len = p - dirpath;
+
+ /* When we run a setuid program we do not accept any directory. */
+ if (__libc_enable_secure)
+ {
+ /* All trusted directory must be complete name. */
+ if (dirpath[0] != '/')
+ continue;
+
+ /* If we got a list of trusted directories only accept one
+ of these. */
+ if (trusted_dirs != NULL)
+ {
+ const char **trust = trusted_dirs;
+
+ while (*trust != NULL)
+ if (memcmp (dirpath, *trust, this_len) == 0
+ && (*trust)[this_len] == '\0')
+ break;
+ else
+ ++trust;
+
+ /* If directory is not trusted, ignore this directory. */
+ if (*trust == NULL)
+ continue;
+ }
+ }
+
+ if (this_len == 0)
{
/* Two adjacent colons, or a colon at the beginning or the end of
the path means to search the current directory. */
@@ -442,10 +472,10 @@ open_path (const char *name, size_t namelen,
else
{
/* Construct the pathname to try. */
- (void) memcpy (buf, dirpath, p - dirpath);
- buf[p - dirpath] = '/';
- (void) memcpy (&buf[(p - dirpath) + 1], name, namelen);
- buflen = p - dirpath + 1 + namelen;
+ (void) memcpy (buf, dirpath, this_len);
+ buf[this_len] = '/';
+ (void) memcpy (&buf[this_len + 1], name, namelen);
+ buflen = this_len + 1 + namelen;
}
fd = __open (buf, O_RDONLY);
@@ -508,9 +538,9 @@ _dl_map_object (struct link_map *loader, const char *name, int type,
size_t namelen = strlen (name) + 1;
- inline void trypath (const char *dirpath)
+ inline void trypath (const char *dirpath, const char *trusted[])
{
- fd = open_path (name, namelen, dirpath, &realname);
+ fd = open_path (name, namelen, dirpath, &realname, trusted);
}
fd = -1;
@@ -521,16 +551,24 @@ _dl_map_object (struct link_map *loader, const char *name, int type,
if (l && l->l_info[DT_RPATH])
trypath ((const char *) (l->l_addr +
l->l_info[DT_STRTAB]->d_un.d_ptr +
- l->l_info[DT_RPATH]->d_un.d_val));
+ l->l_info[DT_RPATH]->d_un.d_val), NULL);
/* If dynamically linked, try the DT_RPATH of the executable itself. */
l = _dl_loaded;
if (fd == -1 && l && l->l_type != lt_loaded && l->l_info[DT_RPATH])
trypath ((const char *) (l->l_addr +
l->l_info[DT_STRTAB]->d_un.d_ptr +
- l->l_info[DT_RPATH]->d_un.d_val));
+ l->l_info[DT_RPATH]->d_un.d_val), NULL);
/* Try an environment variable (unless setuid). */
if (fd == -1 && ! __libc_enable_secure)
- trypath (getenv ("LD_LIBRARY_PATH"));
+ {
+ static const char *trusted_dirs[] =
+ {
+#include "trusted-dirs.h"
+ NULL
+ };
+
+ trypath (getenv ("LD_LIBRARY_PATH"), trusted_dirs);
+ }
if (fd == -1)
{
/* Check the list of libraries in the file /etc/ld.so.cache,
@@ -555,7 +593,7 @@ _dl_map_object (struct link_map *loader, const char *name, int type,
if (fd == -1)
{
extern const char *_dl_rpath; /* Set in rtld.c. */
- trypath (_dl_rpath);
+ trypath (_dl_rpath, NULL);
}
}
else
@@ -590,6 +628,7 @@ _dl_map_object (struct link_map *loader, const char *name, int type,
are only interested in the list of libraries this isn't
so severe. Fake an entry with all the information we
have (in fact only the name). */
+ static const ElfW(Symndx) dummy_bucket = STN_UNDEF;
/* Enter the new object in the list of loaded objects. */
if ((name_copy = local_strdup (name)) == NULL
@@ -599,6 +638,11 @@ _dl_map_object (struct link_map *loader, const char *name, int type,
/* We use an opencount of 0 as a sign for the faked entry. */
l->l_opencount = 0;
l->l_reserved = 0;
+ l->l_buckets = &dummy_bucket;
+ l->l_nbuckets = 1;
+ l->l_relocated = 1;
+
+ return l;
}
else
_dl_signal_error (errno, name, "cannot open shared object file");
diff --git a/elf/ldd.bash.in b/elf/ldd.bash.in
index 6e2b51591a..d174709380 100644
--- a/elf/ldd.bash.in
+++ b/elf/ldd.bash.in
@@ -29,23 +29,39 @@ TEXTDOMAIN=libc
TEXTDOMAINDIR=@TEXTDOMAINDIR@
RTLD=@RTLD@
+RELOCS=
while test $# -gt 0; do
case "$1" in
- --v*)
+ --v | --ve | --ver | --vers | --versi | --versio | --version)
echo $"ldd (GNU libc) @VERSION@
Copyright (C) 1996, 1997 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE."
exit 0 ;;
- --h*)
+ --h | --he | --hel | --help)
echo $"ldd [OPTION]... FILE...
- --help print this help and exit
- --version print version information and exit
+ --help print this help and exit
+ --version print version information and exit
+ -d, --data-relocs process data relocations
+ -r, --function-relocs process data and function relocations
Report bugs using the \`glibcbug' script to <bugs@gnu.ai.mit.edu>."
exit 0 ;;
+ -d | --d | --da | --dat | --data | --data- | --data-r | --data-re | \
+ --data-rel | --data-relo | --data-reloc | --data-relocs)
+ RELOCS='--data-relocs'
+ shift ;;
+ -r | --f | --fu | --fun | --func | --funct | --functi | --functio | \
+ --function | --function- | --function-r | --function-re | --function-rel | \
+ --function-relo | --function-reloc | --function-relocs)
+ RELOCS='--function-relocs'
+ shift ;;
--) # Stop option processing.
shift; break ;;
+ -*)
+ echo >&2 $"ldd: unrecognized option" "\`$1'"
+ echo >&2 $"Try \`ldd --help' for more information."
+ exit 1 ;;
*)
break ;;
esac
@@ -53,9 +69,8 @@ done
case $# in
0)
- echo >&2 $"\
-ldd: missing file arguments
-Try \`ldd --help' for more information."
+ echo >&2 $"ldd: missing file arguments"
+ echo >&2 $"Try \`ldd --help' for more information."
exit 1 ;;
1)
# We don't list the file name when there is only one.
@@ -65,14 +80,21 @@ Try \`ldd --help' for more information."
esac
if test ! -f "$file"; then
echo "${file}:" $"no such file"
- elif ${RTLD} --verify "$file"; then
- LD_TRACE_LOADED_OBJECTS=1 exec ${RTLD} "$file" && exit 1
+ exit 1
else
- echo $" not a dynamic executable"
+ test -x "$file" ||
+ echo $"warning: you do not have execution permission for" "\`$file'"
+ if ${RTLD} --verify "$file"; then
+ LD_TRACE_LOADED_OBJECTS=1 exec ${RTLD} ${RELOCS} "$file" || exit 1
+ else
+ echo $" not a dynamic executable"
+ exit 1
+ fi
fi
exit ;;
*)
set -e # Bail out immediately if ${RTLD} loses on any argument.
+ result=0
for file; do
echo "${file}:"
case "$file" in
@@ -80,16 +102,22 @@ Try \`ldd --help' for more information."
*) file="./$file" ;;
esac
if test ! -f "$file"; then
- echo "$file:" $"no such file"
- elif ${RTLD} --verify "$file"; then
- LD_TRACE_LOADED_OBJECTS=1 ${RTLD} "$file"
+ echo "${file}:" $"no such file"
+ result=1
else
- echo $" not a dynamic executable"
+ test -x "$file" ||
+ echo $"warning: you do not have execution permission for" "\`$file'"
+ if ${RTLD} --verify "$file"; then
+ LD_TRACE_LOADED_OBJECTS=1 ${RTLD} ${RELOCS} "$file" || result=1
+ else
+ echo $" not a dynamic executable"
+ result=1
+ fi
fi
done
esac
-exit 0
+exit $result
# Local Variables:
# mode:ksh
# End:
diff --git a/elf/ldd.sh.in b/elf/ldd.sh.in
index 5b6cc3a75d..4351578b6d 100644
--- a/elf/ldd.sh.in
+++ b/elf/ldd.sh.in
@@ -25,23 +25,40 @@
# variable LD_TRACE_LOADED_OBJECTS to a non-empty value.
RTLD=@RTLD@
+RELOCS=
while test $# -gt 0; do
case "$1" in
- --v*)
+ --v | --ve | --ver | --vers | --versi | --versio | --version)
echo 'ldd (GNU libc) @VERSION@
Copyright (C) 1996, 1997 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.'
exit 0 ;;
- --h*)
+ --h | --he | --hel | --help)
echo "ldd [OPTION]... FILE...
- --help print this help and exit
- --version print version information and exit
+ --help print this help and exit
+ --version print version information and exit
+ -d, --data-relocs process data relocations
+ -r, --function-relocs process data and function relocations
Report bugs using the \`glibcbug' script to <bugs@gnu.ai.mit.edu>."
exit 0 ;;
+ -d | --d | --da | --dat | --data | --data- | --data-r | --data-re | \
+ --data-rel | --data-relo | --data-reloc | --data-relocs)
+ RELOCS='--data-relocs'
+ shift ;;
+ -r | --f | --fu | --fun | --func | --funct | --functi | --functio | \
+ --function | --function- | --function-r | --function-re | --function-rel | \
+ --function-relo | --function-reloc | --function-relocs)
+ RELOCS='--function-relocs'
+ shift ;;
--) # Stop option processing.
shift; break ;;
+ -*)
+ echo >&2 "\
+ldd: unrecognized option \`$1'
+Try \`ldd --help' for more information."
+ exit 1 ;;
*)
break ;;
esac
@@ -61,14 +78,21 @@ Try \`ldd --help' for more information."
esac
if test ! -f "$file"; then
echo "${file}: no such file"
- elif ${RTLD} --verify "$file"; then
- LD_TRACE_LOADED_OBJECTS=1 exec ${RTLD} "$file" && exit 1
+ exit 1
else
- echo ' not a dynamic executable'
+ test -x "$file" ||
+ echo "warning: you do not have execution permission for \`$file'"
+ if ${RTLD} --verify "$file"; then
+ LD_TRACE_LOADED_OBJECTS=1 exec ${RTLD} ${RELOCS} "$file" || exit 1
+ else
+ echo ' not a dynamic executable'
+ exit 1
+ fi
fi
exit ;;
*)
set -e # Bail out immediately if ${RTLD} loses on any argument.
+ result=0
for file; do
echo "${file}:"
case "$file" in
@@ -76,13 +100,19 @@ Try \`ldd --help' for more information."
*) file="./$file" ;;
esac
if test ! -f "$file"; then
- echo "$file: no such file"
- elif ${RTLD} --verify "$file"; then
- LD_TRACE_LOADED_OBJECTS=1 ${RTLD} "$file"
+ echo "${file}: no such file"
+ result=1
else
- echo ' not a dynamic executable'
+ test -x "$file" ||
+ echo "warning: you do not have execution permission for \`$file'"
+ if ${RTLD} --verify "$file"; then
+ LD_TRACE_LOADED_OBJECTS=1 ${RTLD} ${RELOCS} "$file" || result=1
+ else
+ echo ' not a dynamic executable'
+ result=1
+ fi
fi
done
esac
-exit 0
+exit $result
diff --git a/elf/link.h b/elf/link.h
index 7e0b60793f..95d8f0912d 100644
--- a/elf/link.h
+++ b/elf/link.h
@@ -137,6 +137,12 @@ struct link_map
unsigned int l_global:1; /* Nonzero if object in _dl_global_scope. */
unsigned int l_reserved:2; /* Reserved for internal use. */
};
+
+
+/* Function used as argument for `_dl_receive_error' function. The
+ arguments are the error string and the objname the error occurred
+ in. */
+typedef void (*receiver_fct) (const char *, const char *);
/* Internal functions of the run-time dynamic linker.
These can be accessed if you link again the dynamic linker
@@ -161,6 +167,11 @@ extern int _dl_sysdep_open_zero_fill (void); /* dl-sysdep.c */
are concatenated to form the message to print. */
extern void _dl_sysdep_message (const char *string, ...);
+/* OS-dependent function to write a message on the standard error.
+ All arguments are `const char *'; args until a null pointer
+ are concatenated to form the message to print. */
+extern void _dl_sysdep_error (const char *string, ...);
+
/* OS-dependent function to give a fatal error message and exit
when the dynamic linker fails before the program is fully linked.
All arguments are `const char *'; args until a null pointer
@@ -177,11 +188,9 @@ extern int _dl_secure;
zero; OBJECT is the name of the problematical shared object, or null if
it is a general problem; ERRSTRING is a string describing the specific
problem. */
-
extern void _dl_signal_error (int errcode,
const char *object,
- const char *errstring)
- __attribute__ ((__noreturn__));
+ const char *errstring);
/* Call OPERATE, catching errors from `dl_signal_error'. If there is no
error, *ERRSTRING is set to null. If there is an error, *ERRSTRING and
@@ -192,6 +201,11 @@ extern int _dl_catch_error (char **errstring,
const char **object,
void (*operate) (void));
+/* Call OPERATE, receiving errors from `dl_signal_error'. Unlike
+ `_dl_catch_error' the operation is resumed after the OPERATE
+ function returns. */
+extern void _dl_receive_error (receiver_fct fct, void (*operate) (void));
+
/* Helper function for <dlfcn.h> functions. Runs the OPERATE function via
_dl_catch_error. Returns zero for success, nonzero for failure; and
diff --git a/elf/rtld.c b/elf/rtld.c
index 39435f8243..f9a2cd3d03 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -44,6 +44,10 @@ extern void *_dl_sysdep_read_whole_file (const char *filename,
size_t *filesize_ptr,
int mmap_prot);
+/* Helper function to handle errors while resolving symbols. */
+static void print_unresolved (const char *errstring, const char *objname);
+
+
int _dl_argc;
char **_dl_argv;
const char *_dl_rpath;
@@ -142,11 +146,19 @@ dl_main (const ElfW(Phdr) *phdr,
enum { normal, list, verify, trace } mode;
struct link_map **preloads;
unsigned int npreloads;
+ const char *preloadlist;
size_t file_size;
char *file;
mode = getenv ("LD_TRACE_LOADED_OBJECTS") != NULL ? trace : normal;
+ /* LAZY is determined by the parameters --datadeps and --function-deps
+ if we trace the binary. */
+ if (mode == trace)
+ lazy = -1;
+ else
+ lazy = !__libc_enable_secure && *(getenv ("LD_BIND_NOW") ?: "") == '\0';
+
/* Set up a flag which tells we are just starting. */
_dl_starting_up = 1;
@@ -186,22 +198,44 @@ of this helper program; chances are you did not intend to run this program.\n",
/* Note the place where the dynamic linker actually came from. */
_dl_rtld_map.l_name = _dl_argv[0];
- if (! strcmp (_dl_argv[1], "--list"))
- {
- mode = list;
+ while (_dl_argc > 1)
+ if (! strcmp (_dl_argv[1], "--list"))
+ {
+ mode = list;
+ lazy = -1; /* This means do no dependency analysis. */
- ++_dl_skip_args;
- --_dl_argc;
- ++_dl_argv;
- }
- else if (! strcmp (_dl_argv[1], "--verify"))
- {
- mode = verify;
+ ++_dl_skip_args;
+ --_dl_argc;
+ ++_dl_argv;
+ }
+ else if (! strcmp (_dl_argv[1], "--verify"))
+ {
+ mode = verify;
- ++_dl_skip_args;
- --_dl_argc;
- ++_dl_argv;
- }
+ ++_dl_skip_args;
+ --_dl_argc;
+ ++_dl_argv;
+ }
+ else if (! strcmp (_dl_argv[1], "--data-relocs"))
+ {
+ mode = trace;
+ lazy = 1; /* This means do only data relocation analysis. */
+
+ ++_dl_skip_args;
+ --_dl_argc;
+ ++_dl_argv;
+ }
+ else if (! strcmp (_dl_argv[1], "--function-relocs"))
+ {
+ mode = trace;
+ lazy = 0; /* This means do also function relocation analysis. */
+
+ ++_dl_skip_args;
+ --_dl_argc;
+ ++_dl_argv;
+ }
+ else
+ break;
++_dl_skip_args;
--_dl_argc;
@@ -311,23 +345,22 @@ of this helper program; chances are you did not intend to run this program.\n",
preloads = NULL;
npreloads = 0;
- if (! __libc_enable_secure)
+ preloadlist = getenv ("LD_PRELOAD");
+ if (preloadlist)
{
- const char *preloadlist = getenv ("LD_PRELOAD");
- if (preloadlist)
- {
- /* The LD_PRELOAD environment variable gives a white space
- separated list of libraries that are loaded before the
- executable's dependencies and prepended to the global
- scope list. */
- char *list = strdupa (preloadlist);
- char *p;
- while ((p = strsep (&list, " ")) != NULL)
- {
- (void) _dl_map_object (NULL, p, lt_library, 0);
- ++npreloads;
- }
- }
+ /* The LD_PRELOAD environment variable gives a white space
+ separated list of libraries that are loaded before the
+ executable's dependencies and prepended to the global scope
+ list. If the binary is running setuid all elements
+ containing a '/' are ignored since it is insecure. */
+ char *list = strdupa (preloadlist);
+ char *p;
+ while ((p = strsep (&list, " ")) != NULL)
+ if (! __libc_enable_secure || strchr (p, '/') == NULL)
+ {
+ (void) _dl_map_object (NULL, p, lt_library, 0);
+ ++npreloads;
+ }
}
/* Read the contents of the file. */
@@ -496,12 +529,31 @@ of this helper program; chances are you did not intend to run this program.\n",
*--bp = '0';
_dl_sysdep_message (" in object at 0x", bp, "\n", NULL);
}
+ else if (lazy >= 0)
+ {
+ /* We have to do symbol dependency testing. */
+ void doit (void)
+ {
+ _dl_relocate_object (l, _dl_object_relocation_scope (l), lazy);
+ }
+
+ l = _dl_loaded;
+ while (l->l_next)
+ l = l->l_next;
+ do
+ {
+ if (l != &_dl_rtld_map && l->l_opencount > 0)
+ {
+ _dl_receive_error (print_unresolved, doit);
+ *_dl_global_scope_end = NULL;
+ }
+ l = l->l_prev;
+ } while (l);
+ }
_exit (0);
}
- lazy = !__libc_enable_secure && *(getenv ("LD_BIND_NOW") ?: "") == '\0';
-
{
/* Now we have all the objects loaded. Relocate them all except for
the dynamic linker itself. We do this in reverse order so that copy
@@ -573,3 +625,11 @@ of this helper program; chances are you did not intend to run this program.\n",
/* Once we return, _dl_sysdep_start will invoke
the DT_INIT functions and then *USER_ENTRY. */
}
+
+/* This is a little helper function for resolving symbols while
+ tracing the binary. */
+static void
+print_unresolved (const char *errstring, const char *objname)
+{
+ _dl_sysdep_error (errstring, " (", objname, ")\n", NULL);
+}