On Mon, Aug 28, 2017 at 05:11:00PM +0000, alexander.stef...@infineon.com wrote: > > > diff --git a/drivers/char/tpm/tpm-dev-common.c > > > b/drivers/char/tpm/tpm-dev-common.c > > > index 610638a..c39b581 100644 > > > --- a/drivers/char/tpm/tpm-dev-common.c > > > +++ b/drivers/char/tpm/tpm-dev-common.c > > > @@ -119,7 +119,7 @@ ssize_t tpm_common_write(struct file *file, const > > char __user *buf, > > > return -EPIPE; > > > } > > > out_size = tpm_transmit(priv->chip, space, priv->data_buffer, > > > - sizeof(priv->data_buffer), 0); > > > + sizeof(priv->data_buffer), in_size, 0); > > > > Why you couldn't just > > > > unsigned int bufsiz; > > > > /* ... */ > > > > bufsiz = sizeof(priv->data_buffer); > > if (in_size < bufsiz) > > bufsiz = in_size; > > > > out_size = tpm_transmit(priv->chip, space, priv->data_buffer, bufsiz, 0); > > Because the code needs to know both how large the buffer is (in order to > avoid buffer overflows when writing to it) and how much of the data in the > buffer is valid (in order not to send random junk to the TPM). This is made > more explicit in PATCH 2/2. > > Your example fails as soon as the response is longer than the command. > > Alexander
Got you. Do the comparison for count tpm-dev-common.c as it is the only call site where this is needed instead of scrabbling with the parameters. In other call sites this is unnecessary at this point. This will also make backporting a factor more sleek. /Jarkko ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ tpmdd-devel mailing list tpmdd-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/tpmdd-devel
