Messages in this thread | | | Subject | Re: [PATCH 1/1] efi/libstub: tpm: zero initialize pointer variables for mixed mode | From | Javier Martinez Canillas <> | Date | Tue, 13 Mar 2018 16:10:32 +0100 |
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[adding linux-integrity and tpmdd-devel since this was discussed in these ML too]
On 03/13/2018 03:09 PM, Ard Biesheuvel wrote: > As reported by Jeremy, running the new TPM libstub code in mixed mode > (i.e., 64-bit kernel on 32-bit UEFI) results in hangs when invoking > the TCG2 protocol, or when accessing the log_tbl pool allocation. > > The reason turns out to be that in both cases, the 64-bit pointer > variables are not fully initialized by the 32-bit EFI code, and so > we should take care to zero initialize these variables beforehand, > or we'll end up dereferencing bogus pointers. > > Reported-by: Jeremy Cline <jeremy@jcline.org> > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > --- > drivers/firmware/efi/libstub/tpm.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/firmware/efi/libstub/tpm.c b/drivers/firmware/efi/libstub/tpm.c > index da661bf8cb96..13c1edd37e96 100644 > --- a/drivers/firmware/efi/libstub/tpm.c > +++ b/drivers/firmware/efi/libstub/tpm.c > @@ -68,11 +68,11 @@ void efi_retrieve_tpm2_eventlog_1_2(efi_system_table_t *sys_table_arg) > efi_guid_t linux_eventlog_guid = LINUX_EFI_TPM_EVENT_LOG_GUID; > efi_status_t status; > efi_physical_addr_t log_location, log_last_entry; > - struct linux_efi_tpm_eventlog *log_tbl; > + struct linux_efi_tpm_eventlog *log_tbl = NULL; > unsigned long first_entry_addr, last_entry_addr; > size_t log_size, last_entry_size; > efi_bool_t truncated; > - void *tcg2_protocol; > + void *tcg2_protocol = NULL; > > status = efi_call_early(locate_protocol, &tcg2_guid, NULL, > &tcg2_protocol); >
Looks good to me.
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Best regards, -- Javier Martinez Canillas Software Engineer - Desktop Hardware Enablement Red Hat
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