CVE-2019-1010298: Integer Overflow or Wraparound (CWE-190)
value: Linaro/OP-TEE OP-TEE 3.3.0 and earlier is affected by: Buffer Overflow. The impact is: Code execution in the context of TEE core (kernel). The component is: optee_os. The fixed version is: 3.4.0 and later.
CWE description: The product performs a calculation that can
         produce an integer overflow or wraparound when the logic
         assumes that the resulting value will always be larger than
         the original value. This occurs when an integer value is
         incremented to a value that is too large to store in the
         associated representation. When this occurs, the value may
         become a very small or negative number.
CVSS v3 base score: 9.8
Published: 2019-07-15T18:15Z
Repository: https://github.com/OP-TEE/optee_os
Language: C
Files changed: core/tee/tee_svc_cryp.c
Commit date: 2019-01-21 18:28:37 +0100
Commit message: svc: check for allocation overflow in crypto calls part 2

Without checking for overflow there is a risk of allocating a buffer
with size smaller than anticipated and as a consequence of that it might
lead to a heap based overflow with attacker controlled data written
outside the boundaries of the buffer.

Fixes: OP-TEE-2018-0011: "Integer overflow in crypto system calls (x2)"

Signed-off-by: Joakim Bech <joakim.bech@linaro.org>
Tested-by: Joakim Bech <joakim.bech@linaro.org> (QEMU v7, v8)
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
Reported-by: Riscure <inforequest@riscure.com>
Reported-by: Alyssa Milburn <a.a.milburn@vu.nl>
Acked-by: Etienne Carriere <etienne.carriere@linaro.org>

Diff: diff --git a/core/tee/tee_svc_cryp.c b/core/tee/tee_svc_cryp.c
index a5beb339c..f60f3d248 100644
--- a/core/tee/tee_svc_cryp.c
+++ b/core/tee/tee_svc_cryp.c
@@ -3272,11 +3272,16 @@ TEE_Result syscall_asymm_operate(unsigned long state,
 			TEE_MEMORY_ACCESS_ANY_OWNER,
 		(uaddr_t) dst_data, dlen);
 	if (res != TEE_SUCCESS)
 		return res;
 
-	params = malloc(sizeof(TEE_Attribute) * num_params);
+	size_t alloc_size = 0;
+
+	if (MUL_OVERFLOW(sizeof(TEE_Attribute), num_params, &alloc_size))
+		return TEE_ERROR_OVERFLOW;
+
+	params = malloc(alloc_size);
 	if (!params)
 		return TEE_ERROR_OUT_OF_MEMORY;
 	res = copy_in_attrs(utc, usr_params, num_params, params);
 	if (res != TEE_SUCCESS)
 		goto out;
@@ -3434,11 +3439,16 @@ TEE_Result syscall_asymm_verify(unsigned long state,
 					  TEE_MEMORY_ACCESS_ANY_OWNER,
 					  (uaddr_t)sig, sig_len);
 	if (res != TEE_SUCCESS)
 		return res;
 
-	params = malloc(sizeof(TEE_Attribute) * num_params);
+	size_t alloc_size = 0;
+
+	if (MUL_OVERFLOW(sizeof(TEE_Attribute), num_params, &alloc_size))
+		return TEE_ERROR_OVERFLOW;
+
+	params = malloc(alloc_size);
 	if (!params)
 		return TEE_ERROR_OUT_OF_MEMORY;
 	res = copy_in_attrs(utc, usr_params, num_params, params);
 	if (res != TEE_SUCCESS)
 		goto out;

Vulnerable code: 	params = malloc(sizeof(TEE_Attribute) * num_params);
	params = malloc(sizeof(TEE_Attribute) * num_params);
Fixed code: 	size_t alloc_size = 0;

	if (MUL_OVERFLOW(sizeof(TEE_Attribute), num_params, &alloc_size))
		return TEE_ERROR_OVERFLOW;

	params = malloc(alloc_size);
	size_t alloc_size = 0;

	if (MUL_OVERFLOW(sizeof(TEE_Attribute), num_params, &alloc_size))
		return TEE_ERROR_OVERFLOW;

	params = malloc(alloc_size);