Messages in this thread | | | Date | Thu, 9 Mar 2006 04:38:02 +0000 | From | Al Viro <> | Subject | Re: filldir[64] oddness |
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On Wed, Mar 08, 2006 at 11:27:44PM -0500, Dave Jones wrote: > 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 ?
It doesn't dereference it. d_name is an array, not a pointer. FWIW, it should've been
#define NAME_OFFSET(de) offsetof(typeof(de), d_name)
or, better yet
#define NAME_OFFSET offsetof(struct linux_dirent, d_name) #define NAME_OFFSET64 offsetof(struct linux_dirent64, d_name) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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