| Message ID | 20190916085008.22239-1-jarkko.sakkinen@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | tpm: Wrap the buffer from the caller to tpm_buf in tpm_send() | expand |
On Mon Sep 16 19, Jarkko Sakkinen wrote: >tpm_send() does not give anymore the result back to the caller. This >would require another memcpy(), which kind of tells that the whole >approach is somewhat broken. Instead, as Mimi suggested, this commit >just wraps the data to the tpm_buf, and thus the result will not go to >the garbage. > >Obviously this assumes from the caller that it passes large enough >buffer, which makes the whole API somewhat broken because it could be >different size than @buflen but since trusted keys is the only module >using this API right now I think that this fix is sufficient for the >moment. > >In the near future the plan is to replace the parameters with a tpm_buf >created by the caller. > >Reported-by: Mimi Zohar <zohar@linux.ibm.com> >Suggested-by: Mimi Zohar <zohar@linux.ibm.com> >Cc: stable@vger.kernel.org >Fixes: 412eb585587a ("use tpm_buf in tpm_transmit_cmd() as the IO parameter") >Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> >--- > drivers/char/tpm/tpm-interface.c | 8 ++------ > 1 file changed, 2 insertions(+), 6 deletions(-) > >diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c >index d9ace5480665..2459d36dd8cc 100644 >--- a/drivers/char/tpm/tpm-interface.c >+++ b/drivers/char/tpm/tpm-interface.c >@@ -358,13 +358,9 @@ int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen) > if (!chip) > return -ENODEV; > >- rc = tpm_buf_init(&buf, 0, 0); >- if (rc) >- goto out; >- >- memcpy(buf.data, cmd, buflen); >+ buf.data = cmd; > rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to a send a command"); >- tpm_buf_destroy(&buf); >+ > out: > tpm_put_ops(chip); > return rc; >-- >2.20.1 > Nothing uses the out label any longer so it should be dropped as well, but other than that... Acked-by: Jerry Snitselaar <jsnitsel@redhat.com>
On Mon Sep 16 19, Jerry Snitselaar wrote: >On Mon Sep 16 19, Jarkko Sakkinen wrote: >>tpm_send() does not give anymore the result back to the caller. This >>would require another memcpy(), which kind of tells that the whole >>approach is somewhat broken. Instead, as Mimi suggested, this commit >>just wraps the data to the tpm_buf, and thus the result will not go to >>the garbage. >> >>Obviously this assumes from the caller that it passes large enough >>buffer, which makes the whole API somewhat broken because it could be >>different size than @buflen but since trusted keys is the only module >>using this API right now I think that this fix is sufficient for the >>moment. >> >>In the near future the plan is to replace the parameters with a tpm_buf >>created by the caller. >> >>Reported-by: Mimi Zohar <zohar@linux.ibm.com> >>Suggested-by: Mimi Zohar <zohar@linux.ibm.com> >>Cc: stable@vger.kernel.org >>Fixes: 412eb585587a ("use tpm_buf in tpm_transmit_cmd() as the IO parameter") >>Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> >>--- >>drivers/char/tpm/tpm-interface.c | 8 ++------ >>1 file changed, 2 insertions(+), 6 deletions(-) >> >>diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c >>index d9ace5480665..2459d36dd8cc 100644 >>--- a/drivers/char/tpm/tpm-interface.c >>+++ b/drivers/char/tpm/tpm-interface.c >>@@ -358,13 +358,9 @@ int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen) >> if (!chip) >> return -ENODEV; >> >>- rc = tpm_buf_init(&buf, 0, 0); >>- if (rc) >>- goto out; >>- >>- memcpy(buf.data, cmd, buflen); >>+ buf.data = cmd; >> rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to a send a command"); >>- tpm_buf_destroy(&buf); >>+ >>out: >> tpm_put_ops(chip); >> return rc; >>-- >>2.20.1 >> > >Nothing uses the out label any longer so it should be dropped as well, but other than that... > >Acked-by: Jerry Snitselaar <jsnitsel@redhat.com> sigh (wrong emacs macro hit), that should be: Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
On Mon, Sep 16, 2019 at 02:04:54PM -0700, Jerry Snitselaar wrote: > On Mon Sep 16 19, Jerry Snitselaar wrote: > > On Mon Sep 16 19, Jarkko Sakkinen wrote: > > > tpm_send() does not give anymore the result back to the caller. This > > > would require another memcpy(), which kind of tells that the whole > > > approach is somewhat broken. Instead, as Mimi suggested, this commit > > > just wraps the data to the tpm_buf, and thus the result will not go to > > > the garbage. > > > > > > Obviously this assumes from the caller that it passes large enough > > > buffer, which makes the whole API somewhat broken because it could be > > > different size than @buflen but since trusted keys is the only module > > > using this API right now I think that this fix is sufficient for the > > > moment. > > > > > > In the near future the plan is to replace the parameters with a tpm_buf > > > created by the caller. > > > > > > Reported-by: Mimi Zohar <zohar@linux.ibm.com> > > > Suggested-by: Mimi Zohar <zohar@linux.ibm.com> > > > Cc: stable@vger.kernel.org > > > Fixes: 412eb585587a ("use tpm_buf in tpm_transmit_cmd() as the IO parameter") > > > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> > > > --- > > > drivers/char/tpm/tpm-interface.c | 8 ++------ > > > 1 file changed, 2 insertions(+), 6 deletions(-) > > > > > > diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c > > > index d9ace5480665..2459d36dd8cc 100644 > > > --- a/drivers/char/tpm/tpm-interface.c > > > +++ b/drivers/char/tpm/tpm-interface.c > > > @@ -358,13 +358,9 @@ int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen) > > > if (!chip) > > > return -ENODEV; > > > > > > - rc = tpm_buf_init(&buf, 0, 0); > > > - if (rc) > > > - goto out; > > > - > > > - memcpy(buf.data, cmd, buflen); > > > + buf.data = cmd; > > > rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to a send a command"); > > > - tpm_buf_destroy(&buf); > > > + > > > out: > > > tpm_put_ops(chip); > > > return rc; > > > -- > > > 2.20.1 > > > > > > > Nothing uses the out label any longer so it should be dropped as well, but other than that... > > > > Acked-by: Jerry Snitselaar <jsnitsel@redhat.com> > > sigh (wrong emacs macro hit), that should be: > > Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com> Thank you! I pushed the commit to master/next. /Jarkko
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index d9ace5480665..2459d36dd8cc 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -358,13 +358,9 @@ int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen) if (!chip) return -ENODEV; - rc = tpm_buf_init(&buf, 0, 0); - if (rc) - goto out; - - memcpy(buf.data, cmd, buflen); + buf.data = cmd; rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to a send a command"); - tpm_buf_destroy(&buf); + out: tpm_put_ops(chip); return rc;
tpm_send() does not give anymore the result back to the caller. This would require another memcpy(), which kind of tells that the whole approach is somewhat broken. Instead, as Mimi suggested, this commit just wraps the data to the tpm_buf, and thus the result will not go to the garbage. Obviously this assumes from the caller that it passes large enough buffer, which makes the whole API somewhat broken because it could be different size than @buflen but since trusted keys is the only module using this API right now I think that this fix is sufficient for the moment. In the near future the plan is to replace the parameters with a tpm_buf created by the caller. Reported-by: Mimi Zohar <zohar@linux.ibm.com> Suggested-by: Mimi Zohar <zohar@linux.ibm.com> Cc: stable@vger.kernel.org Fixes: 412eb585587a ("use tpm_buf in tpm_transmit_cmd() as the IO parameter") Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> --- drivers/char/tpm/tpm-interface.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-)