github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-09-22 12:44:03 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

tpm: st33zp24: Validate locality read result

Browse Source 
check_locality() treats every nonzero transport return as success. SPI
errors remain negative, while the I2C path can convert a negative write
error through its byte-sized status variable. Either result is nonzero
even though the TPM_ACCESS byte can remain unwritten, so indeterminate
ACTIVE_LOCALITY and VALID bits can falsely report an active locality.

Require recv() to return exactly the requested byte before examining
TPM_ACCESS. Transport errors and short reads now report an inactive
locality, while successful reads retain the existing behavior.

This issue was found by a static analysis checker and confirmed by manual
source review.

Fixes: 251a7b0821 ("TPM: STMicroelectronics ST33 I2C KERNEL 3.x")
Signed-off-by: Ruoyu Wang <ruoyuw560@gmail.com>
Link: https://lore.kernel.org/r/20260813153032.3951878-2-ruoyuw560@gmail.com
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
This commit is contained in:
Ruoyu Wang 2026-08-13 23:30:32 +08:00 committed by Jarkko Sakkinen
parent 8b92687708
commit 264216889d
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/char/tpm/st33zp24/st33zp24.c
View File

@ -106,10 +106,10 @@ static bool check_locality(struct tpm_chip *chip)
{
struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev);
u8 data;
u8 status;
int status;
status = tpm_dev->ops->recv(tpm_dev->phy_id, TPM_ACCESS, &data, 1);
if (status && (data &
if (status == 1 && (data &
(TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
(TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID))
return true;