On Sat, Dec 02, 2023 at 01:34:32PM -0800, Kees Cook wrote: > On Sat, Dec 02, 2023 at 09:28:46PM +0000, Al Viro wrote: > > On Sat, Dec 02, 2023 at 01:22:13PM -0800, Kees Cook wrote: > > > Allow __free(iput) markings for easier cleanup on inode allocations. > > > > NAK. That's a bloody awful idea for that particular data type, since > > 1) ERR_PTR(...) is not uncommon and passing it to iput() is a bug. > > Ah, sounds like instead of "if (_T)", you'd rather see > "if (!IS_ERR_OR_NULL(_T))" ? No. I would rather *not* see IS_ERR_OR_NULL anywhere, but that's a separate rant. > > 2) the common pattern is to have reference-consuming primitives, > > with failure exits normally *not* having to do iput() at all. > > This I'm not following. If I make a call to "new_inode(sb)" that I end > up not using, I need to call "iput()" in it... > > How should this patch be written to avoid the iput() on failure? > https://lore.kernel.org/all/20231202212217.243710-4-keescook@xxxxxxxxxxxx/ I'll poke around and see what I can suggest; said that, one thing I have spotted there on the quick look is that you are exposing hashed dentry associated with your inode before you set its ->i_private. Have an open() hit just after that d_add() and this static int pstore_file_open(struct inode *inode, struct file *file) { struct pstore_private *ps = inode->i_private; struct seq_file *sf; int err; const struct seq_operations *sops = NULL; if (ps->record->type == PSTORE_TYPE_FTRACE) ... with happily oops on you.
