Avoid leaking memory in thread_hash (and enable memory leak detection
authorBodo Möller <bodo@openssl.org>
Sat, 29 Apr 2000 23:58:05 +0000 (23:58 +0000)
committerBodo Möller <bodo@openssl.org>
Sat, 29 Apr 2000 23:58:05 +0000 (23:58 +0000)
for it).

CHANGES
crypto/err/err.c
crypto/err/err.h

diff --git a/CHANGES b/CHANGES
index 0e8a4c6..cc07f74 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -4,6 +4,12 @@
 
  Changes between 0.9.5a and 0.9.6  [xx XXX 2000]
 
+  *) Avoid 'thread_hash' memory leak in crypto/err/err.c by freeing
+     it in ERR_remove_state if appropriate, and change ERR_get_state
+     accordingly to avoid race conditions (this is necessary because
+     thread_hash is no longer constant once set).
+     [Bodo Moeller]
+
   *) Bugfix for linux-elf makefile.one.
      [Ulf Möller]
 
index a013557..c8dba52 100644 (file)
 #include <openssl/crypto.h>
 #include "cryptlib.h"
 #include <openssl/buffer.h>
-#include <openssl/err.h>
-#include <openssl/crypto.h>
 #include <openssl/bio.h>
+#include <openssl/err.h>
 
 
 static LHASH *error_hash=NULL;
@@ -545,6 +544,7 @@ LHASH *ERR_get_string_table(void)
        return(error_hash);
        }
 
+/* not thread-safe */
 LHASH *ERR_get_err_state_table(void)
        {
        return(thread_hash);
@@ -652,6 +652,12 @@ void ERR_remove_state(unsigned long pid)
        tmp.pid=pid;
        CRYPTO_w_lock(CRYPTO_LOCK_ERR);
        p=(ERR_STATE *)lh_delete(thread_hash,&tmp);
+       if (lh_num_items(thread_hash) == 0)
+               {
+               /* make sure we don't leak memory */
+               lh_free(thread_hash);
+               thread_hash = NULL;
+               }
        CRYPTO_w_unlock(CRYPTO_LOCK_ERR);
 
        if (p != NULL) ERR_STATE_free(p);
@@ -661,33 +667,19 @@ ERR_STATE *ERR_get_state(void)
        {
        static ERR_STATE fallback;
        ERR_STATE *ret=NULL,tmp,*tmpp;
+       int thread_state_exists;
        int i;
        unsigned long pid;
 
        pid=(unsigned long)CRYPTO_thread_id();
 
        CRYPTO_r_lock(CRYPTO_LOCK_ERR);
-       if (thread_hash == NULL)
-               {
-               CRYPTO_r_unlock(CRYPTO_LOCK_ERR);
-               CRYPTO_w_lock(CRYPTO_LOCK_ERR);
-               if (thread_hash == NULL)
-                       {
-                       MemCheck_off();
-                       thread_hash=lh_new(pid_hash,pid_cmp);
-                       MemCheck_on();
-                       CRYPTO_w_unlock(CRYPTO_LOCK_ERR);
-                       if (thread_hash == NULL) return(&fallback);
-                       }
-               else
-                       CRYPTO_w_unlock(CRYPTO_LOCK_ERR);
-               }
-       else
+       if (thread_hash != NULL)
                {
                tmp.pid=pid;
                ret=(ERR_STATE *)lh_retrieve(thread_hash,&tmp);
-               CRYPTO_r_unlock(CRYPTO_LOCK_ERR);
                }
+       CRYPTO_r_unlock(CRYPTO_LOCK_ERR);
 
        /* ret == the error state, if NULL, make a new one */
        if (ret == NULL)
@@ -702,9 +694,29 @@ ERR_STATE *ERR_get_state(void)
                        ret->err_data[i]=NULL;
                        ret->err_data_flags[i]=0;
                        }
+
                CRYPTO_w_lock(CRYPTO_LOCK_ERR);
-               tmpp=(ERR_STATE *)lh_insert(thread_hash,ret);
+
+               /* no entry yet in thread_hash for current thread -
+                * thus, it may have changed since we last looked at it */
+               if (thread_hash == NULL)
+                       thread_hash = lh_new(pid_hash, pid_cmp);
+               if (thread_hash == NULL)
+                       thread_state_exists = 0; /* allocation error */
+               else
+                       {
+                       tmpp=(ERR_STATE *)lh_insert(thread_hash,ret);
+                       thread_state_exists = 1;
+                       }
+
                CRYPTO_w_unlock(CRYPTO_LOCK_ERR);
+
+               if (!thread_state_exists)
+                       {
+                       ERR_STATE_free(ret); /* could not insert it */
+                       return(&fallback);
+                       }
+               
                if (tmpp != NULL) /* old entry - should not happen */
                        {
                        ERR_STATE_free(tmpp);
index e3984bb..eb62af2 100644 (file)
@@ -253,14 +253,12 @@ void ERR_remove_state(unsigned long pid); /* if zero we look it up */
 ERR_STATE *ERR_get_state(void);
 
 #ifdef HEADER_LHASH_H
-LHASH *ERR_get_string_table(void );
-LHASH *ERR_get_err_state_table(void );
-#else
-char *ERR_get_string_table(void );
-char *ERR_get_err_state_table(void );
+LHASH *ERR_get_string_table(void);
+LHASH *ERR_get_err_state_table(void); /* even less thread-safe than
+                                      * ERR_get_string_table :-) */
 #endif
 
-int ERR_get_next_error_library(void );
+int ERR_get_next_error_library(void);
 
 #ifdef __cplusplus
 }