4.4-stable review patch. If anyone has any objections, please let me know.
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From: Jeremy Boone jeremy.boone@nccgroup.trust
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 jeremy.boone@nccgroup.trust Cc: stable@vger.kernel.org Signed-off-by: James Bottomley James.Bottomley@HansenPartnership.com Reviewed-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com Tested-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com Signed-off-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com Signed-off-by: James Morris james.morris@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/char/tpm/tpm-interface.c | 5 +++++ drivers/char/tpm/tpm2-cmd.c | 6 ++++++ 2 files changed, 11 insertions(+)
--- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -1040,6 +1040,11 @@ 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; + } + memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
dest += recd; --- a/drivers/char/tpm/tpm2-cmd.c +++ b/drivers/char/tpm/tpm2-cmd.c @@ -622,6 +622,11 @@ 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; + } + data = &buf.data[TPM_HEADER_SIZE + 6];
memcpy(payload->key, data, data_len - 1); @@ -629,6 +634,7 @@ static int tpm2_unseal_cmd(struct tpm_ch payload->migratable = data[data_len - 1]; }
+out: tpm_buf_destroy(&buf); return rc; }