Commit-ID: 79832f0b5f718e0023d9dd73e6845310609a564d Gitweb: https://git.kernel.org/tip/79832f0b5f718e0023d9dd73e6845310609a564d Author: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> AuthorDate: Tue, 13 Mar 2018 14:09:21 +0000 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Tue, 13 Mar 2018 15:28:29 +0100 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@xxxxxxxxxx> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: hdegoede@xxxxxxxxxx Cc: jarkko.sakkinen@xxxxxxxxxxxxxxx Cc: javierm@xxxxxxxxxx Cc: linux-efi@xxxxxxxxxxxxxxx Cc: tweek@xxxxxxxxxx Link: http://lkml.kernel.org/r/20180313140922.17266-2-ard.biesheuvel@xxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- 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); -- 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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