[PATCH] efi_loader: Check for pointers before appending to the eventlog
The TCG protocol returns EFI_SUCCESS even when it fails to install. If the protocol is not installed there should be no calls to tcg2_agile_log_append(). However there are calls to this function occurring outside the TCG protocol invocation (e.g tcg2_measure_pe_image).
Let's deal with this and shield the code from crashing while complaining, so buggy code can be spotted and fixed.
Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org --- Heinrich this is rebased on top of https://lore.kernel.org/u-boot/20211123115335.125252-1-ruchika.gupta@linaro.... lib/efi_loader/efi_tcg2.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c index 133fe8291a92..57a1f37695f6 100644 --- a/lib/efi_loader/efi_tcg2.c +++ b/lib/efi_loader/efi_tcg2.c @@ -311,6 +311,17 @@ static efi_status_t tcg2_agile_log_append(u32 pcr_index, u32 event_type, struct efi_tcg2_final_events_table *final_event; efi_status_t ret = EFI_SUCCESS;
+ /* + * This should never happen. This function should only be invoked if + * the TCG2 protocol has been installed. However since we always + * return EFI_SUCCESS from efi_tcg2_register shield callers against + * crashing and complain + */ + if (!event_log.final_buffer || !event_log.buffer) { + log_err("EFI TCG2 protocol not installed\n"); + return EFI_INVALID_PARAMETER; + } + /* if ExitBootServices hasn't been called update the normal log */ if (!event_log.ebs_called) { if (event_log.truncated ||
Hi Heinrich,
On Tue, 23 Nov 2021 at 18:24, Ilias Apalodimas ilias.apalodimas@linaro.org wrote:
The TCG protocol returns EFI_SUCCESS even when it fails to install. If the protocol is not installed there should be no calls to tcg2_agile_log_append(). However there are calls to this function occurring outside the TCG protocol invocation (e.g tcg2_measure_pe_image).
Let's deal with this and shield the code from crashing while complaining, so buggy code can be spotted and fixed.
Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org
Heinrich this is rebased on top of https://lore.kernel.org/u-boot/20211123115335.125252-1-ruchika.gupta@linaro.... lib/efi_loader/efi_tcg2.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c index 133fe8291a92..57a1f37695f6 100644 --- a/lib/efi_loader/efi_tcg2.c +++ b/lib/efi_loader/efi_tcg2.c @@ -311,6 +311,17 @@ static efi_status_t tcg2_agile_log_append(u32 pcr_index, u32 event_type, struct efi_tcg2_final_events_table *final_event; efi_status_t ret = EFI_SUCCESS;
/** This should never happen. This function should only be invoked if* the TCG2 protocol has been installed. However since we always* return EFI_SUCCESS from efi_tcg2_register shield callers against* crashing and complain*/if (!event_log.final_buffer || !event_log.buffer) {log_err("EFI TCG2 protocol not installed\n");return EFI_INVALID_PARAMETER;}/* if ExitBootServices hasn't been called update the normal log */ if (!event_log.ebs_called) { if (event_log.truncated ||-- 2.34.0
With the latest patch sent from Ruchika [1], this doesn't work properly anymore. I'll rebase/fix it once that one is applied.
[1] https://lore.kernel.org/u-boot/CAC_iWjLPfwos2_x9e536jxwufQ3g7JhuzyEBf8s70MBE...
Regards /Ilias
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Ilias Apalodimas