Dear Shahriyar,
Thank you for your patch.
Am 03.10.25 um 11:25 schrieb Shahriyar Jalayeri:
Ensure tpm_inf_recv() does not overflow the provided buffer when
the TPM reports more data than the caller expects.
Is it possible to enforce this situation to ensure your patch works?
Signed-off-by: Shahriyar Jalayeri <[email protected]>
---
drivers/char/tpm/tpm_infineon.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/char/tpm/tpm_infineon.c b/drivers/char/tpm/tpm_infineon.c
index 7638b65b8..eb6dd55ff 100644
--- a/drivers/char/tpm/tpm_infineon.c
+++ b/drivers/char/tpm/tpm_infineon.c
@@ -250,6 +250,12 @@ static int tpm_inf_recv(struct tpm_chip *chip, u8 * buf,
size_t count)
number_of_wtx = 0;
recv_begin:
+ if (count < 4) {
+ dev_err(&chip->dev,
+ "count less than the header size!\n");
Mention both values count and 4?
+ return -EIO;
+ }
+
This is not described in the commit message.
/* start receiving header */
for (i = 0; i < 4; i++) {
ret = wait(chip, STAT_RDA);
@@ -268,6 +274,12 @@ static int tpm_inf_recv(struct tpm_chip *chip, u8 * buf,
size_t count)
/* size of the data received */
size = ((buf[2] << 8) | buf[3]);
+ if (size > count) {
+ dev_err(&chip->dev,
+ "Buffer too small for incoming data!\n");
I’d log both values, and also specify that the operation is aborted.
+ return -EIO;
+ }
+
for (i = 0; i < size; i++) {
wait(chip, STAT_RDA);
buf[i] = tpm_data_in(RDFIFO);
Kind regards,
Paul
