From a0019e13a9e97e56d8e4f4fbaa745babc6f61f5d Mon Sep 17 00:00:00 2001 From: Alexander Steffen Date: Tue, 13 Jun 2023 20:02:56 +0200 Subject: [PATCH] tpm_tis: Explicitly check for error code commit 513253f8c293c0c8bd46d09d337fc892bf8f9f48 upstream. recv_data either returns the number of received bytes, or a negative value representing an error code. Adding the return value directly to the total number of received bytes therefore looks a little weird, since it might add a negative error code to a sum of bytes. The following check for size < expected usually makes the function return ETIME in that case, so it does not cause too many problems in practice. But to make the code look cleaner and because the caller might still be interested in the original error code, explicitly check for the presence of an error code and pass that through. Cc: stable@vger.kernel.org Fixes: cb5354253af2 ("[PATCH] tpm: spacing cleanups 2") Signed-off-by: Alexander Steffen Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen Signed-off-by: Greg Kroah-Hartman --- drivers/char/tpm/tpm_tis_core.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index cb0660304e48..ef47d1d58ac3 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -266,6 +266,7 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count) int size = 0; int status; u32 expected; + int rc; if (count < TPM_HEADER_SIZE) { size = -EIO; @@ -285,8 +286,13 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count) goto out; } - size += recv_data(chip, &buf[TPM_HEADER_SIZE], - expected - TPM_HEADER_SIZE); + rc = recv_data(chip, &buf[TPM_HEADER_SIZE], + expected - TPM_HEADER_SIZE); + if (rc < 0) { + size = rc; + goto out; + } + size += rc; if (size < expected) { dev_err(&chip->dev, "Unable to read remainder of result\n"); size = -ETIME;