I was reviewing old warnings and I stumbled across this one again. Although I wrote that &fd.key->cat and "fd.key" are equivalent, I feel that actually we should be doing the former. fd.key is a union but we want the ->cat member of the union. On Tue, Jan 26, 2016 at 01:54:06PM -0800, Viacheslav Dubeyko wrote: > On Tue, 2016-01-26 at 22:18 +0300, Dan Carpenter wrote: > > Hm, I completely didn't see that it was a union instead of a struct. I > > still think my fix is actually correct though. Now that you point out > > the union, I see that my change is equivalent to just removing the '&' > > char. > > > > - memcpy(&rd->key, &fd.key, sizeof(struct hfs_cat_key)); > > + memcpy(&rd->key, fd.key, sizeof(struct hfs_cat_key)); > > > > Yeahh, it looks correct right now. The rd is the pointer that includes > struct hfs_cat_key object. So, we need to use &rd->key. But on another > side we have struct hfs_find_data object on the stack. And this object > includes the pointer on union btree_key. We want to copy struct > hfs_cat_key object and we should use sizeof(struct hfs_cat_key). I've read this paragraph several times now and I think you are saying that the patch is correct. > > > We don't want to copy sizeof(*fd.key) because that would write past the > > end of the destination struct. > > > > On Tue, Jan 26, 2016 at 10:18:56AM -0800, Viacheslav Dubeyko wrote: > > > Another worry could be the "search_key" field of the struct > > > hfs_find_data. > > > > I don't understand what you mean here. > > > > I mean here that we could have another incorrect copy operations for > "search_key" field. That's all. I don't see the bugs you are saying might exist... ;) regards, dan carpenter -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
