get_burstcount() can return -EBUSY on timeout. When this happens,
st33zp24_send() returns directly without releasing the locality
acquired earlier.

Use goto out_err to ensure proper cleanup when get_burstcount() fails.

Fixes: bf38b8710892 ("tpm/tpm_i2c_stm_st33: Split tpm_i2c_tpm_st33 in 2 layers (core + phy)")
Signed-off-by: Alper Ak <alperyasinak1@gmail.com>
---
 drivers/char/tpm/st33zp24/st33zp24.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/char/tpm/st33zp24/st33zp24.c b/drivers/char/tpm/st33zp24/st33zp24.c
index 2ed7815e4899..e2b7451ea7cc 100644
--- a/drivers/char/tpm/st33zp24/st33zp24.c
+++ b/drivers/char/tpm/st33zp24/st33zp24.c
@@ -328,8 +328,10 @@ static int st33zp24_send(struct tpm_chip *chip, unsigned char *buf,
 
 	for (i = 0; i < len - 1;) {
 		burstcnt = get_burstcount(chip);
-		if (burstcnt < 0)
-			return burstcnt;
+		if (burstcnt < 0) {
+			ret = burstcnt;
+			goto out_err;
+		}
 		size = min_t(int, len - i - 1, burstcnt);
 		ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_DATA_FIFO,
 					 buf + i, size);
-- 
2.43.0

On Fri, Dec 26, 2025 at 03:09:27PM +0300, Alper Ak wrote:
> get_burstcount() can return -EBUSY on timeout. When this happens,
> st33zp24_send() returns directly without releasing the locality
> acquired earlier.
> 
> Use goto out_err to ensure proper cleanup when get_burstcount() fails.
> 
> Fixes: bf38b8710892 ("tpm/tpm_i2c_stm_st33: Split tpm_i2c_tpm_st33 in 2 layers (core + phy)")
> Signed-off-by: Alper Ak <alperyasinak1@gmail.com>
> ---
>  drivers/char/tpm/st33zp24/st33zp24.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/char/tpm/st33zp24/st33zp24.c b/drivers/char/tpm/st33zp24/st33zp24.c
> index 2ed7815e4899..e2b7451ea7cc 100644
> --- a/drivers/char/tpm/st33zp24/st33zp24.c
> +++ b/drivers/char/tpm/st33zp24/st33zp24.c
> @@ -328,8 +328,10 @@ static int st33zp24_send(struct tpm_chip *chip, unsigned char *buf,
>  
>  	for (i = 0; i < len - 1;) {
>  		burstcnt = get_burstcount(chip);
> -		if (burstcnt < 0)
> -			return burstcnt;
> +		if (burstcnt < 0) {
> +			ret = burstcnt;
> +			goto out_err;
> +		}
>  		size = min_t(int, len - i - 1, burstcnt);
>  		ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_DATA_FIFO,
>  					 buf + i, size);
> -- 
> 2.43.0
> 

Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>

BR, Jarkko