From bf3a1a8c9120f0cc55dc65993674bc1ac1f2968a Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Wed, 8 Sep 2021 08:33:57 +0300 Subject: [PATCH] tpm: Check for integer overflow in tpm2_map_response_body() commit a0bcce2b2a169e10eb265c8f0ebdd5ae4c875670 upstream. The "4 * be32_to_cpu(data->count)" multiplication can potentially overflow which would lead to memory corruption. Add a check for that. Cc: stable@vger.kernel.org Fixes: 745b361e989a ("tpm: infrastructure for TPM spaces") Signed-off-by: Dan Carpenter Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen Signed-off-by: Greg Kroah-Hartman --- 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 9f4e22dcde270..205d930d7ea60 100644 --- a/drivers/char/tpm/tpm2-space.c +++ b/drivers/char/tpm/tpm2-space.c @@ -419,6 +419,9 @@ 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; -- 2.51.0