Re: [viro-vfs:more.configfs] [configfs] 2bbdcd7eab: BUG:kernel_NULL_pointer_dereference,address

On Fri, Jun 05, 2026 at 08:11:12AM +0100, Al Viro wrote:
> On Fri, Jun 05, 2026 at 01:52:28PM +0800, kernel test robot wrote:
> > 
> > 
> > 
> > Hello,
> > 
> > kernel test robot noticed "BUG:kernel_NULL_pointer_dereference,address" on:
> > 
> > commit: 2bbdcd7eabfcd3a5bd2614ab75ece19323d5f4c2 ("configfs: attach the subtree only when it's completely built")
> > https://git.kernel.org/cgit/linux/kernel/git/viro/vfs.git more.configfs
> > 
> > in testcase: boot
> > 
> > config: i386-randconfig-013-20260604
> > compiler: gcc-14
> > test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 32G
> > 
> > (please refer to attached dmesg/kmsg for entire log/backtrace)
> 
> D'oh...  Minimal incremental to deal with that would probably be something like
> the delta below, but it's probably better to have configfs_add_subtree() return
> the resulting dentry instead...

... as in updated (and force-pushed) branch.