Erez Zadok <ezk@xxxxxxxxxxxxxxxxx> writes: > Niklos, I forgot to mention that I had to apply a small fix to a VFS > bug in fs/namei.c:1362, where a mix of symlinks and renames, using > racer, triggers an BUG_ON at the VFS layer (very reproducible). > Without this fix, racer oopses in the VFS well before it gets to > trigger overlayfs bugs. It's a pity 2.6.39 was released with this > very reproducible *VFS* level bug (doesn't anyone run racer+fsx+ltp > before releasing a new kernel?) > > Anyway, here's the small patch here. Clearly viro/hch need to review > this "fix" b/c I'm not sure it's really the right one Patch looks good to me. Acked-by: Miklos Szeredi <mszeredi@xxxxxxx> If you've got a patch fixing a serious bug, you'd better send it to Linus and Andrew (as well as the VFS maintainers), where it'll get more prompt evaluation. You can still do that, also adding "CC: stable@xxxxxxxxxx" to the SOB block in the patch so that the fix quickly makes it into the 2.6.39 stable series. Thanks, Miklos > > VFS: move BUG_ON test for symlink nd->depth after current->link_count test > > This solves a bug in nested_symlink (which was rewritten from > do_follow_link), and follows the order of depth tests that existed before. > The bug triggers a BUG_ON in fs/namei.c:1346, when running racer with > symlink and rename ops. > > Signed-off-by: Erez Zadok <ezk@xxxxxxxxxxxxx> > diff --git a/fs/namei.c b/fs/namei.c > index 017c3fa..7a93387 100644 > --- a/fs/namei.c > +++ b/fs/namei.c > @@ -1343,12 +1343,12 @@ static inline int nested_symlink(struct path *path, struct nameidata *nd) > { > int res; > > - BUG_ON(nd->depth >= MAX_NESTED_LINKS); > if (unlikely(current->link_count >= MAX_NESTED_LINKS)) { > path_put_conditional(path, nd); > path_put(&nd->path); > return -ELOOP; > } > + BUG_ON(nd->depth >= MAX_NESTED_LINKS); > > nd->depth++; > current->link_count++; -- 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