On Sat, Apr 30, 2016 at 06:33:36PM -0400, Jeff Layton wrote: > I'll do the same (re: KASAN). > > Also FWIW, a few months ago I hit some oopses in the same inline > function (get_freepointer). It turned out to be a double-free due to my > own misuse of the fsnotify API. I wonder though if this might also be a > double free somewhere? It is a double-free somewhere, all right... What happens there is that nfs_readdir really relies upon being the only thread to manipulate the page cache of that directory. We get nfs_revalidate_mapping() called and if it ends up evicting a page currently in use by nfs_do_filldir(), you get nfs_readdir_clear_array() called _twice_ - once on kicking it out of page cache (and those kfree of the names are obviously Not Good(tm) for nfs_do_filldir() copying those names to userland) and then when nfs_do_filldir() gets to cache_page_release(). Sigh... -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
