On 12.06.2017 at 17:24 wrote Greg Kroah-Hartman: > 4.11-stable review patch. If anyone has any objections, please let me know. > > ------------------ > > From: Dave Young <[email protected]> > > commit 7425826f4f7ac60f2538b06a7f0a5d1006405159 upstream. > > Sabrina Dubroca reported an early panic: > > BUG: unable to handle kernel paging request at ffffffffff240001 > IP: efi_bgrt_init+0xdc/0x134 > > [...] > > ---[ end Kernel panic - not syncing: Attempted to kill the idle task! > > ... which was introduced by: > > 7b0a911478c7 ("efi/x86: Move the EFI BGRT init code to early init code") > > The cause is that on this machine the firmware provides the EFI ACPI BGRT > table even on legacy non-EFI bootups - which table should be EFI only. > > The garbage BGRT data causes the efi_bgrt_init() panic. > > Add a check to skip efi_bgrt_init() in case non-EFI bootup to work around > this firmware bug. > > Tested-by: Sabrina Dubroca <[email protected]> > Signed-off-by: Dave Young <[email protected]> > Signed-off-by: Ard Biesheuvel <[email protected]> > Signed-off-by: Matt Fleming <[email protected]> > Cc: Linus Torvalds <[email protected]> > Cc: Peter Zijlstra <[email protected]> > Cc: Thomas Gleixner <[email protected]> > Cc: [email protected] > Fixes: 7b0a911478c7 ("efi/x86: Move the EFI BGRT init code to early init > code") > Link: http://lkml.kernel.org/r/[email protected] > [ Rewrote the changelog to be more readable. ] > Signed-off-by: Ingo Molnar <[email protected]> > Signed-off-by: Greg Kroah-Hartman <[email protected]> > > --- > arch/x86/platform/efi/efi-bgrt.c | 3 +++ > 1 file changed, 3 insertions(+) > > --- a/arch/x86/platform/efi/efi-bgrt.c > +++ b/arch/x86/platform/efi/efi-bgrt.c > @@ -36,6 +36,9 @@ void __init efi_bgrt_init(struct acpi_ta > if (acpi_disabled) > return; > > + if (!efi_enabled(EFI_BOOT)) > + return; > + > if (table->length < sizeof(bgrt_tab)) { > pr_notice("Ignoring BGRT: invalid length %u (expected %zu)\n", > table->length, sizeof(bgrt_tab)); > > >
The patch is ok but it only fixes BIOS systems. To fix the regression above (commit 7b0a911478c7) for EFI systems it needs this patch as well: commit 792ef14df5c585c19b2831673a077504a09e5203 master (efi: Fix boot panic because of invalid BGRT image address)
