[bug #45729] Reboot or hang when missing network modules

[Jason Tang]

URL:
  <http://savannah.gnu.org/bugs/?45729>

                 Summary: Reboot or hang when missing network modules
                 Project: GNU GRUB
            Submitted by: dev_null42
            Submitted on: Tue 11 Aug 2015 12:31:27 AM GMT
                Category: Network
                Severity: Major
                Priority: 5 - Normal
              Item Group: Software Error
                  Status: None
                 Privacy: Public
             Assigned to: None
         Originator Name: Jason Tang
        Originator Email: address@hidden
             Open/Closed: Open
         Discussion Lock: Any
                 Release: 
                 Release: Git master
         Reproducibility: Every Time
         Planned Release: None

    _______________________________________________________

Details:

On a modern x86 UEFI system, I tried PXE booting GRUB2. After the "Welcome to
GRUB!" message, GRUB would either (a) reboot itself, (b) hang, or (c) go into
an infinite loop. I traced the problem down to grub-core/net/net.c, in
grub_net_open_real(). I had accidentally not included the TFTP module into
bootx64.efi.

There is no error checking on the call to grub_dl_load() for tftp (nor http).
If the load fails, GRUB continues running and seems to corrupt its call stack,
thus accounting for the observed inconsistent behavior. I propose that the
code should check the return value to grub_dl_load(). If it is zero, then GRUB
should panic and go into a failure mode, instead of continuing.





    _______________________________________________________

Reply to this item at:

  <http://savannah.gnu.org/bugs/?45729>

_______________________________________________
  Message sent via/by Savannah
  http://savannah.gnu.org/