filldir[64] oddness

From: Dave Jones
Date: Wed Mar 08 2006 - 23:25:34 EST


I'm puzzled by an aparent use of uninitialised memory
that coverity's checker picked up.

fs/readdir.c

#define NAME_OFFSET(de) ((int) ((de)->d_name - (char __user *) (de)))
#define ROUND_UP(x) (((x)+sizeof(long)-1) & ~(sizeof(long)-1))

140 static int filldir(void * __buf, const char * name, int namlen, loff_t offset,
141 ino_t ino, unsigned int d_type)
142 {
143 struct linux_dirent __user * dirent;
144 struct getdents_callback * buf = (struct getdents_callback *) __buf
145 int reclen = ROUND_UP(NAME_OFFSET(dirent) + namlen + 2);

How come that NAME_OFFSET isn't causing an oops when
it dereferences stackjunk->d_name ?

Dave

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http://www.codemonkey.org.uk
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