tpm: Fix heap buffer overflow in tpm_transmit_cmd()

struct tpm_buf now uses an embedded flexible array for data, which is
6 bytes shorter than TPM_BUFSIZE due to the struct header. But
tpm_transmit_cmd() still passes PAGE_SIZE to tpm_transmit(), and after
clamping to TPM_BUFSIZE in tpm_try_transmit(), chip->ops->recv() can
write past the end of data[] by 6 bytes.

Pass buf->capacity to tpm_transmit() instead.

Fixes: 3d9e043dab0a ("tpm-buf: Memory-safe allocations")
Cc: stable@vger.kernel.org
Signed-off-by: Jiangshan Yi <yijiangshan@kylinos.cn>
Link: https://lore.kernel.org/r/20260901062850.379870-1-yijiangshan@kylinos.cn
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>

0 files changed, 0 insertions, 0 deletions