From 9dfea3de7f690bff70e3c6eb346b9ad082bb2e35 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Sat, 7 Sep 2024 08:32:32 -0700 Subject: [PATCH] libio: Set _vtable_offset before calling _IO_link_in [BZ #32148] Since _IO_vtable_offset is used to detect the old binaries, set it in _IO_old_file_init_internal before calling _IO_link_in which checks _IO_vtable_offset. Add a glibc 2.0 test with copy relocation on _IO_stderr_@GLIBC_2.0 to verify that fopen won't cause memory corruption. This fixes BZ #32148. Signed-off-by: H.J. Lu Reviewed-by: Noah Goldstein --- libio/Makefile | 7 ++++ libio/oldfileops.c | 4 +- libio/tst-fopen-compat.c | 85 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 95 insertions(+), 1 deletion(-) create mode 100644 libio/tst-fopen-compat.c diff --git a/libio/Makefile b/libio/Makefile index ae90e343ad..ae704d8767 100644 --- a/libio/Makefile +++ b/libio/Makefile @@ -293,11 +293,18 @@ endif ifeq ($(build-shared),yes) aux += oldfileops oldstdfiles tests += \ + tst-fopen-compat \ tst-stderr-compat \ # tests tests-2.0 += \ + tst-fopen-compat \ tst-stderr-compat \ # tests-2.0 + +tst-fopen-compat-ARGS = tst-fopen-compat.c +# Disable PIE to trigger copy relocation. +CFLAGS-tst-fopen-compat.c += -fno-pie +tst-fopen-compat-no-pie = yes endif shared-only-routines = oldiofopen oldiofdopen oldiofclose oldfileops \ diff --git a/libio/oldfileops.c b/libio/oldfileops.c index 97148dba9b..8f775c9094 100644 --- a/libio/oldfileops.c +++ b/libio/oldfileops.c @@ -103,9 +103,11 @@ _IO_old_file_init_internal (struct _IO_FILE_plus *fp) fp->file._old_offset = _IO_pos_BAD; fp->file._flags |= CLOSED_FILEBUF_FLAGS; - _IO_link_in (fp); + /* NB: _vtable_offset must be set before calling _IO_link_in since + _IO_vtable_offset is used to detect the old binaries. */ fp->file._vtable_offset = ((int) sizeof (struct _IO_FILE) - (int) sizeof (struct _IO_FILE_complete)); + _IO_link_in (fp); fp->file._fileno = -1; if (&_IO_stdin_used != NULL || !_IO_legacy_file ((FILE *) fp)) diff --git a/libio/tst-fopen-compat.c b/libio/tst-fopen-compat.c new file mode 100644 index 0000000000..f241b61043 --- /dev/null +++ b/libio/tst-fopen-compat.c @@ -0,0 +1,85 @@ +/* Verify that fopen works with copy relocation on _IO_stderr_ in binaries + linked with glibc 2.0. + Copyright (C) 2024 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 + . */ + +#include + +#if TEST_COMPAT (libc, GLIBC_2_0, GLIBC_2_1) +# define _LIBC +# define _IO_USE_OLD_IO_FILE +# include +# include +# include +# include +# include +# include + +struct _IO_jump_t; + +struct _IO_FILE_plus +{ + FILE file; + const struct _IO_jump_t *vtable; +}; + +extern struct _IO_FILE_plus _IO_stderr_; +compat_symbol_reference (libc, _IO_stderr_, _IO_stderr_, GLIBC_2_0); +compat_symbol_reference (libc, fopen, fopen, GLIBC_2_0); +compat_symbol_reference (libc, fclose, fclose, GLIBC_2_0); + +static int +do_test (int argc, char *argv[]) +{ + static char filename[PATH_MAX + 1]; + struct stat st; + char *name = NULL; + int i; + + /* Try to trigger copy relocation. */ + TEST_VERIFY_EXIT (_IO_stderr_.file._fileno == STDERR_FILENO); + + for (i = 1; i < argc; i++) + { + name = argv[i]; + if (stat (name, &st) == 0) + { + TEST_VERIFY_EXIT (strlen (name) <= PATH_MAX); + break; + } + } + TEST_VERIFY_EXIT (name != NULL); + + strcpy (filename, name); + FILE *fp = fopen (filename, "r"); + TEST_VERIFY_EXIT (strcmp (filename, name) == 0); + TEST_VERIFY_EXIT (fp != NULL); + TEST_VERIFY_EXIT (fclose (fp) == 0); + return 0; +} +#else +# include + +static int +do_test (int argc, char *argv[]) +{ + return EXIT_UNSUPPORTED; +} +#endif + +#define TEST_FUNCTION_ARGV do_test +#include -- 2.43.5