Re: [syzbot] [fs?] [efi?] BUG: unable to handle kernel paging request in alloc_fs_context

Christian Brauner
2025-05-22T12:24:15Z

On Wed, May 21, 2025 at 07:28:34PM +0200, Ard Biesheuvel wrote:
> (cc James, Al, Christian)
>
> Please see the splat below.
>
> The NULL dereference is due to get_cred() in alloc_fs_context()
> attempting to increment current->cred->usage while current->cred ==
> NULL, and this is a result of the fact that PM notifier call chain is
> called while the task is exiting.
>
> IIRC, the intent was for commit
>
> 11092db5b573 efivarfs: fix NULL dereference on resume
>
> to be replaced at some point with something more robust; might that
> address this issue as well?

Yes. It's in the merge queue for v6.16 which kills off all that
vfs_kern_mount() stuff.