On 14 May 2018 at 09:50, tip-bot for Hans de Goede <tipbot@xxxxxxxxx> wrote: > Commit-ID: 1de3a1be8a9345fd0c7d9bb1009b21afe6b6b10f > Gitweb: https://git.kernel.org/tip/1de3a1be8a9345fd0c7d9bb1009b21afe6b6b10f > Author: Hans de Goede <hdegoede@xxxxxxxxxx> > AuthorDate: Fri, 4 May 2018 08:00:01 +0200 > Committer: Ingo Molnar <mingo@xxxxxxxxxx> > CommitDate: Mon, 14 May 2018 08:57:49 +0200 > > efi/x86: Ignore unrealistically large option ROMs > > setup_efi_pci() tries to save a copy of each PCI option ROM as this may > be necessary for the device driver for the PCI device to have access too. > > On some systems the efi_pci_io_protocol's romimage and romsize fields > contain invalid data, which looks a bit like pointers pointing back into > other EFI code or data. Interpreting these pointers as romsize leads to > a very large value and if we then try to alloc this amount of memory to > save a copy the alloc call fails. > > This leads to a "Failed to alloc mem for rom" error being printed on the > EFI console for each PCI device. > > This commit avoids the printing of these errors, by checking romsize before > doing the alloc and if it is larger then the EFI spec limit of 16 MiB > silently ignore the ROM fields instead of trying to alloc mem and fail. > > Tested-by: Hans de Goede <hdegoede@xxxxxxxxxx> > [ardb: deduplicate 32/64 bit changes, use SZ_16M symbolic constant] > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> This looks odd now: I sent this out as Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> [ardb: deduplicate 32/64 bit changes, use SZ_16M symbolic constant] Tested-by: Hans de Goede <hdegoede@xxxxxxxxxx> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> which clearly conveys that Hans tested the updated version of the patch. In general, I don't think there is a need to reorder signoffs unless there is anything wrong with them, no? > Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > Cc: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx> > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Cc: linux-efi@xxxxxxxxxxxxxxx > Link: http://lkml.kernel.org/r/20180504060003.19618-16-ard.biesheuvel@xxxxxxxxxx > Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> > --- > arch/x86/boot/compressed/eboot.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c > index dadf32312082..a8a8642d2b0b 100644 > --- a/arch/x86/boot/compressed/eboot.c > +++ b/arch/x86/boot/compressed/eboot.c > @@ -123,10 +123,17 @@ __setup_efi_pci(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom) > if (status != EFI_SUCCESS) > return status; > > + /* > + * Some firmware images contain EFI function pointers at the place where the > + * romimage and romsize fields are supposed to be. Typically the EFI > + * code is mapped at high addresses, translating to an unrealistically > + * large romsize. The UEFI spec limits the size of option ROMs to 16 > + * MiB so we reject any ROMs over 16 MiB in size to catch this. > + */ > romimage = (void *)(unsigned long)efi_table_attr(efi_pci_io_protocol, > romimage, pci); > romsize = efi_table_attr(efi_pci_io_protocol, romsize, pci); > - if (!romimage || !romsize) > + if (!romimage || !romsize || romsize > SZ_16M) > return EFI_INVALID_PARAMETER; > > size = romsize + sizeof(*rom); -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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