4.14-stable review patch. If anyone has any objections, please let me know.
------------------ From: Jeremy Boone <[email protected]> commit 3be23274755ee85771270a23af7691dc9b3a95db upstream. Discrete TPMs are often connected over slow serial buses which, on some platforms, can have glitches causing bit flips. If a bit does flip it could cause an overrun if it's in one of the size parameters, so sanity check that we're not overrunning the provided buffer when doing a memcpy(). Signed-off-by: Jeremy Boone <[email protected]> Cc: [email protected] Signed-off-by: James Bottomley <[email protected]> Reviewed-by: Jarkko Sakkinen <[email protected]> Tested-by: Jarkko Sakkinen <[email protected]> Signed-off-by: Jarkko Sakkinen <[email protected]> Signed-off-by: James Morris <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/char/tpm/tpm-interface.c | 4 ++++ drivers/char/tpm/tpm2-cmd.c | 4 ++++ 2 files changed, 8 insertions(+) --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -1228,6 +1228,10 @@ int tpm_get_random(u32 chip_num, u8 *out break; recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len); + if (recd > num_bytes) { + total = -EFAULT; + break; + } rlength = be32_to_cpu(tpm_cmd.header.out.length); if (rlength < offsetof(struct tpm_getrandom_out, rng_data) + --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -683,6 +683,10 @@ static int tpm2_unseal_cmd(struct tpm_ch if (!rc) { data_len = be16_to_cpup( (__be16 *) &buf.data[TPM_HEADER_SIZE + 4]); + if (data_len < MIN_KEY_SIZE || data_len > MAX_KEY_SIZE + 1) { + rc = -EFAULT; + goto out; + } rlength = be32_to_cpu(((struct tpm2_cmd *)&buf) ->header.out.length);
