Make use of the struct_size() helper instead of an open-coded version, in order to avoid any potential type mistakes or integer overflows that, in the worse scenario, could lead to heap overflows. Also, address the following sparse warning: drivers/char/tpm/xen-tpmfront.c:131:16: warning: using sizeof on a flexible structure Link: https://github.com/KSPP/linux/issues/160 Link: https://github.com/KSPP/linux/issues/174 Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx> --- drivers/char/tpm/xen-tpmfront.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/char/tpm/xen-tpmfront.c b/drivers/char/tpm/xen-tpmfront.c index da5b30771418..f53e0cf1ec7e 100644 --- a/drivers/char/tpm/xen-tpmfront.c +++ b/drivers/char/tpm/xen-tpmfront.c @@ -126,16 +126,16 @@ static void vtpm_cancel(struct tpm_chip *chip) notify_remote_via_evtchn(priv->evtchn); } -static unsigned int shr_data_offset(struct vtpm_shared_page *shr) +static size_t shr_data_offset(struct vtpm_shared_page *shr) { - return sizeof(*shr) + sizeof(u32) * shr->nr_extra_pages; + return struct_size(shr, extra_pages, shr->nr_extra_pages); } static int vtpm_send(struct tpm_chip *chip, u8 *buf, size_t count) { struct tpm_private *priv = dev_get_drvdata(&chip->dev); struct vtpm_shared_page *shr = priv->shr; - unsigned int offset = shr_data_offset(shr); + size_t offset = shr_data_offset(shr); u32 ordinal; unsigned long duration; @@ -177,7 +177,7 @@ static int vtpm_recv(struct tpm_chip *chip, u8 *buf, size_t count) { struct tpm_private *priv = dev_get_drvdata(&chip->dev); struct vtpm_shared_page *shr = priv->shr; - unsigned int offset = shr_data_offset(shr); + size_t offset = shr_data_offset(shr); size_t length = shr->length; if (shr->state == VTPM_STATE_IDLE) -- 2.27.0
