glibc/SOURCES/glibc-rh2047981-44.patch
2022-08-16 01:27:52 +00:00

99 lines
4.1 KiB
Diff

Downstream-only patch to change rtld_active () to return true during
early audit operations. GLRO (_dl_profile_output) is initialized much
earlier than GLRO (dl_init_all_dirs), before auditors run, so it is a
good replacement.
This is addressed downstream very differently, in this commit:
commit 8dcb6d0af07fda3607b541857e4f3970a74ed55b
Author: Florian Weimer <fweimer@redhat.com>
Date: Tue Apr 26 14:23:02 2022 +0200
dlfcn: Do not use rtld_active () to determine ld.so state (bug 29078)
When audit modules are loaded, ld.so initialization is not yet
complete, and rtld_active () returns false even though ld.so is
mostly working. Instead, the static dlopen hook is used, but that
does not work at all because this is not a static dlopen situation.
Commit 466c1ea15f461edb8e3ffaf5d86d708876343bbf ("dlfcn: Rework
static dlopen hooks") moved the hook pointer into _rtld_global_ro,
which means that separate protection is not needed anymore and the
hook pointer can be checked directly.
The guard for disabling libio vtable hardening in _IO_vtable_check
should stay for now.
Fixes commit 8e1472d2c1e25e6eabc2059170731365f6d5b3d1 ("ld.so:
Examine GLRO to detect inactive loader [BZ #20204]").
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
diff --git a/elf/rtld.c b/elf/rtld.c
index 22cceeab40319582..b47e84ca2fb6f03c 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -2352,9 +2352,7 @@ ERROR: '%s': cannot process note segment.\n", _dl_argv[0]);
GLRO(dl_initial_searchlist) = *GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist;
/* Remember the last search directory added at startup, now that
- malloc will no longer be the one from dl-minimal.c. As a side
- effect, this marks ld.so as initialized, so that the rtld_active
- function returns true from now on. */
+ malloc will no longer be the one from dl-minimal.c. */
GLRO(dl_init_all_dirs) = GL(dl_all_dirs);
/* Print scope information. */
@@ -2675,7 +2673,9 @@ process_envvars (struct dl_main_state *state)
char *envline;
char *debug_output = NULL;
- /* This is the default place for profiling data file. */
+ /* This is the default place for profiling data file. As a side
+ effect, this marks ld.so as initialized, so that the rtld_active
+ function returns true from now on. */
GLRO(dl_profile_output)
= &"/var/tmp\0/var/profile"[__libc_enable_secure ? 9 : 0];
diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h
index d4f70211c34d1c59..9dec9e3d3b6d6aa2 100644
--- a/sysdeps/generic/ldsodefs.h
+++ b/sysdeps/generic/ldsodefs.h
@@ -600,18 +600,18 @@ struct rtld_global_ro
/* Name of the shared object to be profiled (if any). */
EXTERN const char *_dl_profile;
- /* Filename of the output file. */
+ /* Filename of the output file. This is assigned a
+ non-NULL pointer by the ld.so startup code (after initialization
+ to NULL), so this can also serve as an indicator whether a copy
+ of ld.so is initialized and active. See the rtld_active function
+ below. */
EXTERN const char *_dl_profile_output;
/* Name of the object we want to trace the prelinking. */
EXTERN const char *_dl_trace_prelink;
/* Map of shared object to be prelink traced. */
EXTERN struct link_map *_dl_trace_prelink_map;
- /* All search directories defined at startup. This is assigned a
- non-NULL pointer by the ld.so startup code (after initialization
- to NULL), so this can also serve as an indicator whether a copy
- of ld.so is initialized and active. See the rtld_active function
- below. */
+ /* All search directories defined at startup. */
EXTERN struct r_search_path_elem *_dl_init_all_dirs;
#ifdef NEED_DL_SYSINFO
@@ -1259,9 +1259,9 @@ static inline bool
rtld_active (void)
{
/* The default-initialized variable does not have a non-zero
- dl_init_all_dirs member, so this allows us to recognize an
+ dl_profile_output member, so this allows us to recognize an
initialized and active ld.so copy. */
- return GLRO(dl_init_all_dirs) != NULL;
+ return GLRO(dl_profile_output) != NULL;
}
static inline struct auditstate *