From a0bcce2b2a169e10eb265c8f0ebdd5ae4c875670 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Wed, 8 Sep 2021 08:33:57 +0300
Subject: [PATCH] tpm: Check for integer overflow in tpm2_map_response_body()
Git-commit: a0bcce2b2a169e10eb265c8f0ebdd5ae4c875670
Patch-mainline: v5.16-rc1
References: git-fixes
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 <dan.carpenter@oracle.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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;
--
2.26.2