efi/tpm: Fix sanity check of unsigned tbl_size being less than zero

commit be59d57f98065af0b8472f66a0a969207b168680 upstream.

Currently the check for tbl_size being less than zero is always false
because tbl_size is unsigned. Fix this by making it a signed int.

Addresses-Coverity: ("Unsigned compared against 0")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jerry Snitselaar <jsnitsel@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-janitors@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Fixes: e658c82be556 ("efi/tpm: Only set 'efi_tpm_final_log_size' after successful event log parsing")
Link: https://lkml.kernel.org/r/20191008100153.8499-1-colin.king@canonical.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/firmware/efi/tpm.c b/drivers/firmware/efi/tpm.c
index 703469c1ab8ef0abdf62537fefa174a43b4d293c..ebd7977653a8e28b4a7086573c0e3c80d2e271e3 100644 (file)
--- a/drivers/firmware/efi/tpm.c
+++ b/drivers/firmware/efi/tpm.c
@@ -40,7 +40,7 @@ int __init efi_tpm_eventlog_init(void)
 {
        struct linux_efi_tpm_eventlog *log_tbl;
        struct efi_tcg2_final_events_table *final_tbl;
-       unsigned int tbl_size;
+       int tbl_size;
        int ret = 0;
 
        if (efi.tpm_log == EFI_INVALID_TABLE_ADDR) {