man dumps core if no manpath.config directories exist

2002-10-12 Thread Kris Kennaway 
#0  0x0804c7fb in get_manpath (perrs=0, path=0x800 Address 0x800 out of bounds)
at /usr/src/gnu/usr.bin/man/manpath/manpath.c:500
#1  0x0804bf30 in manpath (perrs=0)
at /usr/src/gnu/usr.bin/man/manpath/manpath.c:195
#2  0x08049a2b in man_getopt (argc=0, argv=0x0)
at /usr/src/gnu/usr.bin/man/man/man.c:479
#3  0x080491fe in main (argc=1, argv=0xbfbff78c)
at /usr/src/gnu/usr.bin/man/man/man.c:153
#4  0x080490dc in _start (ap=0xbfbff888 man)
at /usr/src/lib/csu/i386-elf/crt1.c:126

(gdb) frame 0
#0  0x0804c7fb in get_manpath (perrs=0, path=0x800 Address 0x800 out of bounds)
at /usr/src/gnu/usr.bin/man/manpath/manpath.c:500
500   *manpathlist = '\0';
(gdb) print len
$1 = 0

It's pretty clear what's going on..none of the directories in
/etc/manpath.config exist, so len=0, so malloc(0) succeeds and does
nothing, leaving manpathlist a null pointer.

This situation can occur if e.g. you install the 'base' freebsd
distribution into a jail, without installing any of the manpages.  In
this situation none of the manpage directories are created either.

Kris



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[PATCH] Re: man dumps core if no manpath.config directories exist

2002-10-12 Thread Terry Lambert 
Kris Kennaway wrote:
 It's pretty clear what's going on..none of the directories in
 /etc/manpath.config exist, so len=0, so malloc(0) succeeds and does
 nothing, leaving manpathlist a null pointer.
 
 This situation can occur if e.g. you install the 'base' freebsd
 distribution into a jail, without installing any of the manpages.  In
 this situation none of the manpage directories are created either.

Uh... so fix it?

Patch attached.

Yes, this returns a strdup() without verifying the allocation; just
like the caller will return the result of get_manpath() or strdup(),
without verifying the allocation.  This is generally bad code, and
I'm not going to rewrite it to make all the interfaces reflexive,
like they should be, to fix a simple bug.

-- Terry
Index: manpath.c
===
RCS file: /cvs/src/gnu/usr.bin/man/manpath/manpath.c,v
retrieving revision 1.12
diff -c -r1.12 manpath.c
*** manpath.c   13 Feb 2001 16:55:42 -  1.12
--- manpath.c   12 Oct 2002 21:03:09 -
***
*** 493,498 
--- 493,501 
lp++;
  }
  
+   if (!len)
+ return strdup();
+ 
manpathlist = (char *) malloc (len);
if (manpathlist == NULL)
  gripe_alloc (len, manpathlist);

Re: [PATCH] Re: man dumps core if no manpath.config directories exist

2002-10-12 Thread Kris Kennaway 
On Sat, Oct 12, 2002 at 06:02:59PM -0700, Terry Lambert wrote:
 Kris Kennaway wrote:
  It's pretty clear what's going on..none of the directories in
  /etc/manpath.config exist, so len=0, so malloc(0) succeeds and does
  nothing, leaving manpathlist a null pointer.
  
  This situation can occur if e.g. you install the 'base' freebsd
  distribution into a jail, without installing any of the manpages.  In
  this situation none of the manpage directories are created either.
 
 Uh... so fix it?

That's why I reported it.

 Patch attached.

Thanks.

Kris



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