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Bug#31850 Test crashes in "embedded" server

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The mysql_change_user command fails to properly update the database pointer
when no database is selected, leading to "use after free" errors. The same
happens on the user privilege pointer in the thread security context.

The solution is to properly reset and update the database name. Also update
the user_priv pointer so that it doesn't point to freed memory.


sql/sql_connect.cc:
  After a successful call to check_user() without specifying a new
  database name, the previous database thd->db) is freed but the
  pointer is not updated to NULL.
sql/sql_parse.cc:
  Update the security_ctx->priv_user pointer as it is a alias for
  the user security_ctx->user pointer. Also remove unneeded cast,
  the x_free macro casts the argument.
This commit is contained in:
unknown
2007-11-01 17:29:20 -02:00
parent 17d2230550
commit 8f0df2efe8
2 changed files with 12 additions and 16 deletions
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5
sql/sql_parse.cc
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@ -911,6 +911,7 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
/* Clear variables that are allocated */
thd->user_connect= 0;
thd->security_ctx->priv_user= thd->security_ctx->user;
res= check_user(thd, COM_CHANGE_USER, passwd, passwd_len, db, FALSE);
if (res)
@ -933,8 +934,8 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
if (save_user_connect)
decrease_user_connections(save_user_connect);
#endif /* NO_EMBEDDED_ACCESS_CHECKS */
x_free((uchar*) save_db);
x_free((uchar*) save_security_ctx.user);
x_free(save_db);
x_free(save_security_ctx.user);
if (cs_number)
{