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authorJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>2018-09-03 04:01:26 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-11-13 22:08:48 +0300
commitc6d2e2023c2c0dd91cf8ba18fe2fa888aceb0f88 (patch)
treed2c69b8d6317cc6fa1e40f04032b51f681dd082a
parente6d2f788cb714c1675645813feee23306ad39e73 (diff)
downloadlinux-c6d2e2023c2c0dd91cf8ba18fe2fa888aceb0f88.tar.xz
tpm: fix response size validation in tpm_get_random()
commit 84b59f6487d82d3ab4247a099aba66d4d17e8b08 upstream. When checking whether the response is large enough to be able to contain the received random bytes in tpm_get_random() and tpm2_get_random(), they fail to take account the header size, which should be added to the minimum size. This commit fixes this issue. Cc: stable@vger.kernel.org Fixes: c659af78eb7b ("tpm: Check size of response before accessing data") Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/char/tpm/tpm-interface.c3
-rw-r--r--drivers/char/tpm/tpm2-cmd.c4
2 files changed, 5 insertions, 2 deletions
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 9f61106502a9..7d958ff426e0 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -1322,7 +1322,8 @@ int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
}
rlength = be32_to_cpu(tpm_cmd.header.out.length);
- if (rlength < offsetof(struct tpm_getrandom_out, rng_data) +
+ if (rlength < TPM_HEADER_SIZE +
+ offsetof(struct tpm_getrandom_out, rng_data) +
recd) {
total = -EFAULT;
break;
diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index c31b490bd41d..3acf4fd4e5a5 100644
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -329,7 +329,9 @@ int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
&buf.data[TPM_HEADER_SIZE];
recd = min_t(u32, be16_to_cpu(out->size), num_bytes);
if (tpm_buf_length(&buf) <
- offsetof(struct tpm2_get_random_out, buffer) + recd) {
+ TPM_HEADER_SIZE +
+ offsetof(struct tpm2_get_random_out, buffer) +
+ recd) {
err = -EFAULT;
goto out;
}