MySQL Bugs: #7402: null-pointer exception

Bug #7402	null-pointer exception
Submitted:	18 Dec 2004 11:59	Modified:	5 Jan 2005 13:36
Reporter:	Dietrich Teickner	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Query Browser	Severity:	S1 (Critical)
Version:	1.1.2	OS:	Windows (win32)
Assigned to:		CPU Architecture:	Any

Description:
Hi,

I have in
mysql-query-browser-1.1.2\mysql-gui-common\library\source\myx_network.c
a null-pointer exception.
It was not checked the validyti of the returned pointer from gethostbyname(hostname).

int myx_get_ip_as_string(const char *hostname, char *ip)
{
#if defined(__WIN__) || defined(_WIN32) || defined(_WIN64)
  struct in_addr in;
#endif
  struct hostent *phostent;

  phostent= gethostbyname(hostname);

-----------------------> here is the poiner some time zero. !!!!!!!!!!!!!

#if defined(__WIN__) || defined(_WIN32) || defined(_WIN64)
  in.S_un.S_un_b.s_b1= phostent->h_addr_list[0][0];
  in.S_un.S_un_b.s_b2= phostent->h_addr_list[0][1];
  in.S_un.S_un_b.s_b3= phostent->h_addr_list[0][2];
  in.S_un.S_un_b.s_b4= phostent->h_addr_list[0][3];

  sprintf(ip, "%s", inet_ntoa(in));
#else
  strcpy(ip, inet_ntoa(*(struct in_addr*)phostent->h_addr_list[0]));
#endif

  return 0;
}

I find some more situations in  myx_network.c where dose never checked the returned pointer of gethostbyname.

How to repeat:
It is a problem in the source !!

gethostbyname() returns NULL on errors so this should indeed be checked for

Thank you for your bug report. This issue has been committed to our
source repository of that product and will be incorporated into the
next release.

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