summaryrefslogtreecommitdiff
path: root/drivers/firmware
diff options
context:
space:
mode:
authorArd Biesheuvel <ard.biesheuvel@linaro.org>2018-03-13 17:09:21 +0300
committerIngo Molnar <mingo@kernel.org>2018-03-13 17:28:29 +0300
commit79832f0b5f718e0023d9dd73e6845310609a564d (patch)
tree676d06e2e0b97673702dcc7ac8e5a0bfd41028c5 /drivers/firmware
parentfc6eabbbf8ef99efed778dd5afabc83c21dba585 (diff)
downloadlinux-79832f0b5f718e0023d9dd73e6845310609a564d.tar.xz
efi/libstub/tpm: Initialize pointer variables to zero for mixed mode
As reported by Jeremy Cline, 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> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: hdegoede@redhat.com Cc: jarkko.sakkinen@linux.intel.com Cc: javierm@redhat.com Cc: linux-efi@vger.kernel.org Cc: tweek@google.com Link: http://lkml.kernel.org/r/20180313140922.17266-2-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers/firmware')
-rw-r--r--drivers/firmware/efi/libstub/tpm.c4
1 files 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);