| Message ID | 20210908053356.GB28725@kili (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | tpm: Check for integer overflow in tpm2_map_response_body() | expand |
On Wed, 2021-09-08 at 08:33 +0300, Dan Carpenter wrote: > The "4 * be32_to_cpu(data->count)" multiplication can potentially > overflow which would lead to memory corruption. Add a check for that. > > Fixes: 745b361e989a ("tpm: infrastructure for TPM spaces") > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > --- > drivers/char/tpm/tpm2-space.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c > index 784b8b3cb903..97e916856cf3 100644 > --- a/drivers/char/tpm/tpm2-space.c > +++ b/drivers/char/tpm/tpm2-space.c > @@ -455,6 +455,9 @@ static int tpm2_map_response_body(struct tpm_chip *chip, u32 cc, u8 *rsp, > if (be32_to_cpu(data->capability) != TPM2_CAP_HANDLES) > return 0; > > + if (be32_to_cpu(data->count) > (UINT_MAX - TPM_HEADER_SIZE - 9) / 4) > + return -EFAULT; > + > if (len != TPM_HEADER_SIZE + 9 + 4 * be32_to_cpu(data->count)) > return -EFAULT; > Thanks! Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> /Jarkko
diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c index 784b8b3cb903..97e916856cf3 100644 --- a/drivers/char/tpm/tpm2-space.c +++ b/drivers/char/tpm/tpm2-space.c @@ -455,6 +455,9 @@ static int tpm2_map_response_body(struct tpm_chip *chip, u32 cc, u8 *rsp, if (be32_to_cpu(data->capability) != TPM2_CAP_HANDLES) return 0; + if (be32_to_cpu(data->count) > (UINT_MAX - TPM_HEADER_SIZE - 9) / 4) + return -EFAULT; + if (len != TPM_HEADER_SIZE + 9 + 4 * be32_to_cpu(data->count)) return -EFAULT;
The "4 * be32_to_cpu(data->count)" multiplication can potentially overflow which would lead to memory corruption. Add a check for that. Fixes: 745b361e989a ("tpm: infrastructure for TPM spaces") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> --- drivers/char/tpm/tpm2-space.c | 3 +++ 1 file changed, 3 insertions(+)