Nick Wellnhofer <[EMAIL PROTECTED]> writes:
> I found out that the process was looping in enlargeStringInfo() in 
> backend/lib/stringinfo.c.

This problem was reported by someone else recently.  I've just applied
the attached patch.

> The real cause of the problem seems to be a frontend/backend 
> communication problem. The "needed" argument 0x5454502b comes from a 
> 4-byte length field which string content is 'TTP/'. Looks like a part of 
> a HTTP request to me.

Yeah, it kinda sounds like someone is trying to send an HTTP request to
the Postgres port :-(

                        regards, tom lane

*** src/backend/lib/stringinfo.c.orig   Sat Nov 29 17:39:42 2003
--- src/backend/lib/stringinfo.c        Tue May 11 16:00:20 2004
***************
*** 16,21 ****
--- 16,22 ----
  #include "postgres.h"
  
  #include "lib/stringinfo.h"
+ #include "utils/memutils.h"
  
  
  /*
***************
*** 220,226 ****
--- 221,240 ----
  {
        int                     newlen;
  
+       /*
+        * Guard against ridiculous "needed" values, which can occur if we're
+        * fed bogus data.  Without this, we can get an overflow or infinite
+        * loop in the following.
+        */
+       if (needed < 0 ||
+               ((Size) needed) >= (MaxAllocSize - (Size) str->len))
+               elog(ERROR, "invalid string enlargement request size %d",
+                        needed);
+ 
        needed += str->len + 1;         /* total space required now */
+ 
+       /* Because of the above test, we now have needed <= MaxAllocSize */
+ 
        if (needed <= str->maxlen)
                return;                                 /* got enough space already */
  
***************
*** 233,238 ****
--- 247,260 ----
        newlen = 2 * str->maxlen;
        while (needed > newlen)
                newlen = 2 * newlen;
+ 
+       /*
+        * Clamp to MaxAllocSize in case we went past it.  Note we are assuming
+        * here that MaxAllocSize <= INT_MAX/2, else the above loop could
+        * overflow.  We will still have newlen >= needed.
+        */
+       if (newlen > (int) MaxAllocSize)
+               newlen = (int) MaxAllocSize;
  
        str->data = (char *) repalloc(str->data, newlen);
  

---------------------------(end of broadcast)---------------------------
TIP 6: Have you searched our list archives?

               http://archives.postgresql.org

Reply via email to