elf: Handle non-directory name in search path (BZ 31035)

The open_path stops if a relative path in search path contains a
component that is a non directory (for instance, if the component
is an existing file).

For instance:

  $ cat > lib.c <<EOF
  > void foo (void) {}
  > EOF
  $ gcc -shared -fPIC -o lib.so lib.c
  $ cat > main.c <<EOF
  extern void foo ();
  int main () { foo (); return 0; }
  EOF
  $ gcc -o main main.c lib.so
  $ LD_LIBRARY_PATH=. ./main
  $ LD_LIBRARY_PATH=non-existing/path:. ./main
  $ LD_LIBRARY_PATH=$(pwd)/main:. ./main
  $ LD_LIBRARY_PATH=./main:. ./main
  ./main: error while loading shared libraries: lib.so: cannot open shared object file: No such file or directory

The invalid './main' should be ignored as a non-existent one,
instead as a valid but non accessible file.

Absolute paths do not trigger this issue because their status are
initialized as 'unknown' and open_path check if this is a directory.

Checked on x86_64-linux-gnu.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
This commit is contained in:
Adhemerval Zanella 2023-11-10 10:43:12 -03:00
parent 3fddfe3c5d
commit a8dcffb306
5 changed files with 103 additions and 3 deletions

View File

@ -428,6 +428,7 @@ tests += \
tst-nodelete-opened \
tst-nodelete2 \
tst-noload \
tst-non-directory-path \
tst-null-argv \
tst-p_align1 \
tst-p_align2 \
@ -856,6 +857,7 @@ modules-names += \
tst-nodelete-dlclose-plugin \
tst-nodelete-opened-lib \
tst-nodelete2mod \
tst-non-directory-mod \
tst-null-argv-lib \
tst-p_alignmod-base \
tst-p_alignmod3 \
@ -1122,6 +1124,7 @@ ifeq (yes,$(build-shared))
ifeq ($(run-built-tests),yes)
tests-special += \
$(objpfx)argv0test.out \
$(objpfx)tst-non-directory-path.out \
$(objpfx)tst-pathopt.out \
$(objpfx)tst-rtld-help.out \
$(objpfx)tst-rtld-list-diagnostics.out \
@ -2987,3 +2990,12 @@ $(objpfx)tst-decorate-maps: $(shared-thread-library)
tst-decorate-maps-ENV = \
GLIBC_TUNABLES=glibc.malloc.arena_max=8:glibc.malloc.mmap_threshold=1024:glibc.mem.decorate_maps=1
tst-decorate-maps-ARGS = 8
LDFLAGS-tst-non-directory-mod.so = -Wl,-soname,tst-non-directory-mod.so
$(objpfx)tst-non-directory-path: $(objpfx)tst-non-directory-mod.so
$(objpfx)tst-non-directory-path.out: tst-non-directory-path.sh \
$(objpfx)tst-non-directory-path
$(SHELL) tst-non-directory-path.sh $(objpfx)ld.so $(objpfx)tst-non-directory-path \
'$(test-wrapper-env)' '$(run_program_env)' \
'$(rpath-link)' $(objpfx) > $@; \
$(evaluate-test)

View File

@ -1810,7 +1810,6 @@ open_path (const char *name, size_t namelen, int mode,
size_t cnt;
char *edp;
int here_any = 0;
int err;
/* If we are debugging the search for libraries print the path
now if it hasn't happened now. */
@ -1911,8 +1910,12 @@ open_path (const char *name, size_t namelen, int mode,
return -1;
}
}
if (here_any && (err = errno) != ENOENT && err != EACCES)
/* The file exists and is readable, but something went wrong. */
/* Continue the search if the file does not exist (ENOENT), if it can
not be accessed (EACCES), or if the a component in the path is not a
directory (for instance, if the component is a existing file meaning
essentially that the pathname is invalid - ENOTDIR). */
if (here_any && errno != ENOENT && errno != EACCES && errno != ENOTDIR)
return -1;
/* Remember whether we found anything. */

View File

@ -0,0 +1 @@
void foo (void) {}

View File

@ -0,0 +1,7 @@
extern void foo (void);
int main (int argc, char *argv[])
{
foo ();
return 0;
}

77
elf/tst-non-directory-path.sh Executable file
View File

@ -0,0 +1,77 @@
#!/bin/sh
# Test if library search path does not terminates with non-directory
# components.
# Copyright (C) 2023 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
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# The GNU C Library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with the GNU C Library; if not, see
# <https://www.gnu.org/licenses/>.
set -e
rtld=$1
test_program=$2
test_wrapper_env=$3
run_program_env=$4
# Remove the last space to allow concatenate extra paths.
library_path=$(echo $5)
objpfx=$6
test_binary=$(basename ${test_program})
test_libpath=${test_binary}-x
mkdir -p ${objpfx}/${test_libpath}
mv ${objpfx}/tst-non-directory-mod.so ${objpfx}/${test_libpath}
# Check with absolute paths.
${test_wrapper_env} \
${run_program_env} \
$rtld --inhibit-cache \
--library-path \
"$library_path":"${objpfx}"tst-non-directory-invalid:"${objpfx}"${test_libpath} \
$test_program 2>&1 && rc=0 || rc=$?
${test_wrapper_env} \
${run_program_env} \
$rtld --inhibit-cache \
--library-path \
"$library_path":"${objpfx}"${test_binary}:"${objpfx}"${test_libpath} \
$test_program 2>&1 && rc=0 || rc=$?
# Relative paths along with non-existent path in search list.
cd "$objpfx"
${test_wrapper_env} \
${run_program_env} \
$rtld --inhibit-cache \
--library-path \
"$library_path":../elf/tst-non-directory-invalid::../elf/${test_libpath} \
$test_program 2>&1 && rc=0 || rc=$?
# Relative paths along with component in the path is not a directory in search list.
${test_wrapper_env} \
${run_program_env} \
$rtld --inhibit-cache \
--library-path \
"$library_path":../elf/${test_binary}:../elf/${test_libpath} \
$test_program 2>&1 && rc=0 || rc=$?
# Relative paths along with non-existent path and a component in the path that is not a directory.
${test_wrapper_env} \
${run_program_env} \
$rtld --inhibit-cache \
--library-path \
"$library_path":../elf/tst-non-directory-invalid:../elf/${test_binary}:../elf/${test_libpath} \
$test_program 2>&1 && rc=0 || rc=$?
exit $rc