sh: Fix bss-based buffer overflow in . builtin.

If the length of a directory in PATH together with the given filename
exceeded FILENAME_MAX (which may happen even for pathnames that work), a
static buffer was overflown.

The static buffer is unnecessary, we can use the stalloc() stack.

Obtained from:	NetBSD
MFC after:	1 week
This commit is contained in:
Jilles Tjoelker 2011-05-22 12:12:28 +00:00
parent 1cb2359e6f
commit c9e93e6739

View File

@ -281,7 +281,6 @@ readcmdfile(const char *name)
static char *
find_dot_file(char *basename)
{
static char localname[FILENAME_MAX+1];
char *fullname;
const char *path = pathval();
struct stat statb;
@ -291,10 +290,14 @@ find_dot_file(char *basename)
return basename;
while ((fullname = padvance(&path, basename)) != NULL) {
strcpy(localname, fullname);
if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
/*
* Don't bother freeing here, since it will
* be freed by the caller.
*/
return fullname;
}
stunalloc(fullname);
if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode))
return localname;
}
return basename;
}