diff options
| author | Gregory Price <gourry@gourry.net> | 2024-09-13 19:19:51 -0400 |
|---|---|---|
| committer | Ard Biesheuvel <ardb@kernel.org> | 2024-10-15 20:27:29 +0200 |
| commit | e6d654e9f5a97742cfe794b1c4bb5d3fb2d25e98 (patch) | |
| tree | b87836391d58966792aa1a107604c0f8d6450ddf | |
| parent | c004703ed7ae6be30ee7dcb37801bda4c6a24c3b (diff) | |
tpm: fix signed/unsigned bug when checking event logs
A prior bugfix that fixes a signed/unsigned error causes
another signed unsigned error.
A situation where log_tbl->size is invalid can cause the
size passed to memblock_reserve to become negative.
log_size from the main event log is an unsigned int, and
the code reduces to the following
u64 value = (int)unsigned_value;
This results in sign extension, and the value sent to
memblock_reserve becomes effectively negative.
Fixes: be59d57f9806 ("efi/tpm: Fix sanity check of unsigned tbl_size being less than zero")
Signed-off-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
| -rw-r--r-- | drivers/firmware/efi/tpm.c | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/drivers/firmware/efi/tpm.c b/drivers/firmware/efi/tpm.c index e8d69bd548f3..9c3613e6af15 100644 --- a/drivers/firmware/efi/tpm.c +++ b/drivers/firmware/efi/tpm.c @@ -40,7 +40,8 @@ int __init efi_tpm_eventlog_init(void) { struct linux_efi_tpm_eventlog *log_tbl; struct efi_tcg2_final_events_table *final_tbl; - int tbl_size; + unsigned int tbl_size; + int final_tbl_size; int ret = 0; if (efi.tpm_log == EFI_INVALID_TABLE_ADDR) { @@ -80,26 +81,26 @@ int __init efi_tpm_eventlog_init(void) goto out; } - tbl_size = 0; + final_tbl_size = 0; if (final_tbl->nr_events != 0) { void *events = (void *)efi.tpm_final_log + sizeof(final_tbl->version) + sizeof(final_tbl->nr_events); - tbl_size = tpm2_calc_event_log_size(events, - final_tbl->nr_events, - log_tbl->log); + final_tbl_size = tpm2_calc_event_log_size(events, + final_tbl->nr_events, + log_tbl->log); } - if (tbl_size < 0) { + if (final_tbl_size < 0) { pr_err(FW_BUG "Failed to parse event in TPM Final Events Log\n"); ret = -EINVAL; goto out_calc; } memblock_reserve(efi.tpm_final_log, - tbl_size + sizeof(*final_tbl)); - efi_tpm_final_log_size = tbl_size; + final_tbl_size + sizeof(*final_tbl)); + efi_tpm_final_log_size = final_tbl_size; out_calc: early_memunmap(final_tbl, sizeof(*final_tbl)); |