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authorMark Wielaard <mark@klomp.org>2019-05-15 17:14:01 +0200
committerMark Wielaard <mark@klomp.org>2019-05-15 23:34:55 +0200
commit11b451c8868d8a2b0edc5dfd44fc58d9ee538be0 (patch)
tree54af71dd79004a0769dd70c9ab332c73b49a9ae3
parent5dde9ef79a62b305f054ae9594a32e687dafbea6 (diff)
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dlfcn: Guard __dlerror_main_freeres with __libc_once_get (once) [BZ# 24476]
dlerror.c (__dlerror_main_freeres) will try to free resources which only have been initialized when init () has been called. That function is called when resources are needed using __libc_once (once, init) where once is a __libc_once_define (static, once) in the dlerror.c file. Trying to free those resources if init () hasn't been called will produce errors under valgrind memcheck. So guard the freeing of those resources using __libc_once_get (once) and make sure we have a valid key. Also add a similar guard to __dlerror (). * dlfcn/dlerror.c (__dlerror_main_freeres): Guard using __libc_once_get (once) and static_bug == NULL. (__dlerror): Check we have a valid key, set result to static_buf otherwise. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
-rw-r--r--ChangeLog8
-rw-r--r--dlfcn/dlerror.c29
2 files changed, 29 insertions, 8 deletions
diff --git a/ChangeLog b/ChangeLog
index cf6959d2624..ea7b3d4f48a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2019-05-15 Mark Wielaard <mark@klomp.org>
+
+ [BZ# 24476]
+ * dlfcn/dlerror.c (__dlerror_main_freeres): Guard using
+ __libc_once_get (once) and static_buf == NULL.
+ (__dlerror): Check we have a valid key, set result to static_buf
+ otherwise.
+
2019-05-15 Andreas Schwab <schwab@suse.de>
[BZ #20568]
diff --git a/dlfcn/dlerror.c b/dlfcn/dlerror.c
index 27376582d0e..ca42c126c13 100644
--- a/dlfcn/dlerror.c
+++ b/dlfcn/dlerror.c
@@ -72,9 +72,16 @@ __dlerror (void)
__libc_once (once, init);
/* Get error string. */
- result = (struct dl_action_result *) __libc_getspecific (key);
- if (result == NULL)
- result = &last_result;
+ if (static_buf != NULL)
+ result = static_buf;
+ else
+ {
+ /* init () has been run and we don't use the static buffer.
+ So we have a valid key. */
+ result = (struct dl_action_result *) __libc_getspecific (key);
+ if (result == NULL)
+ result = &last_result;
+ }
/* Test whether we already returned the string. */
if (result->returned != 0)
@@ -230,13 +237,19 @@ free_key_mem (void *mem)
void
__dlerror_main_freeres (void)
{
- void *mem;
/* Free the global memory if used. */
check_free (&last_result);
- /* Free the TSD memory if used. */
- mem = __libc_getspecific (key);
- if (mem != NULL)
- free_key_mem (mem);
+
+ if (__libc_once_get (once) && static_buf == NULL)
+ {
+ /* init () has been run and we don't use the static buffer.
+ So we have a valid key. */
+ void *mem;
+ /* Free the TSD memory if used. */
+ mem = __libc_getspecific (key);
+ if (mem != NULL)
+ free_key_mem (mem);
+ }
}
struct dlfcn_hook *_dlfcn_hook __attribute__((nocommon));