5.15-stable review patch. If anyone has any objections, please let me know.
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From: Gregory Price gourry@gourry.net
[ Upstream commit e6d654e9f5a97742cfe794b1c4bb5d3fb2d25e98 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/firmware/efi/tpm.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/drivers/firmware/efi/tpm.c b/drivers/firmware/efi/tpm.c index e8d69bd548f3f..9c3613e6af158 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));