The priv->responce_length can hold the size of an response or an negative error code, and the tpm_common_read() needs to handle both cases correctly. Changed the type of responce_length to signed and accounted for negative value in tpm_common_read()

Cc: stable@vger.kernel.org Fixes: d23d12484307 ("tpm: fix invalid locking in NONBLOCKING mode") Reported-by: Laura Abbott labbott@redhat.com Signed-off-by: Tadeusz Struk tadeusz.struk@intel.com --- drivers/char/tpm/tpm-dev-common.c | 2 +- drivers/char/tpm/tpm-dev.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/char/tpm/tpm-dev-common.c b/drivers/char/tpm/tpm-dev-common.c index b23b0b999232..87f449340202 100644 --- a/drivers/char/tpm/tpm-dev-common.c +++ b/drivers/char/tpm/tpm-dev-common.c @@ -130,7 +130,7 @@ ssize_t tpm_common_read(struct file *file, char __user *buf, priv->response_read = true;

ret_size = min_t(ssize_t, size, priv->response_length); - if (!ret_size) { + if (ret_size <= 0) { priv->response_length = 0; goto out; } diff --git a/drivers/char/tpm/tpm-dev.h b/drivers/char/tpm/tpm-dev.h index 1089fc0bb290..f3742bcc73e3 100644 --- a/drivers/char/tpm/tpm-dev.h +++ b/drivers/char/tpm/tpm-dev.h @@ -14,7 +14,7 @@ struct file_priv { struct work_struct timeout_work; struct work_struct async_work; wait_queue_head_t async_wait; - size_t response_length; + ssize_t response_length; bool response_read; bool command_enqueued;