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authorNick Child <nnac123@gmail.com>2021-07-13 10:00:03 -0400
committerVasant Hegde <hegdevasant@linux.vnet.ibm.com>2021-07-20 10:57:12 +0530
commit355176a9405c83320748f804e8655e6a8ee2324f (patch)
tree5bfe0987656aebf1b63077183d873144080e5389 /libstb/secvar
parentd722dc185bcf86a28ad8710ccc0b5a02b4ea0fc2 (diff)
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secvar: return error if validate_esl has extra data
Currently, in `validate_esl_list`, the return code is initialized to zero (our success value). While looping though the ESL's in the submitted ESL chain, the loop will break if there is not enough data to meet minimum ESL requirements. This condition was not setting a return code, meaning that the successful return code can pass to the end of the function if there is extra data at the end of the ESL. As a consequence, any properly signed update can successfully commit any data (as long as it is less than the min size of an ESL) to the secvars. This commit will return an error if the described condition is met. This means all data in the appended ESL of an auth file must be accounted for. No extra bytes can be added to the end since, on success, this data will become the updated secvar. Additionally, a test case has been added to ensure that this commit addresses the issue correctly. Signed-off-by: Nick Child <nick.child@ibm.com> Reviewed-by: Nayna Jain <nayna@linux.ibm.com> Tested-by: Nayna Jain <nayna@linux.ibm.com> Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Diffstat (limited to 'libstb/secvar')
-rw-r--r--libstb/secvar/backend/edk2-compat-process.c5
-rw-r--r--libstb/secvar/test/secvar-test-edk2-compat.c15
2 files changed, 19 insertions, 1 deletions
diff --git a/libstb/secvar/backend/edk2-compat-process.c b/libstb/secvar/backend/edk2-compat-process.c
index 076e0cc..3fab634 100644
--- a/libstb/secvar/backend/edk2-compat-process.c
+++ b/libstb/secvar/backend/edk2-compat-process.c
@@ -267,8 +267,11 @@ int validate_esl_list(const char *key, const char *esl, const size_t size)
while (eslvarsize > 0) {
prlog(PR_DEBUG, "esl var size is %d offset is %lu\n", eslvarsize, size - eslvarsize);
- if (eslvarsize < sizeof(EFI_SIGNATURE_LIST))
+ if (eslvarsize < sizeof(EFI_SIGNATURE_LIST)) {
+ prlog(PR_ERR, "ESL with size %d is too small\n", eslvarsize);
+ rc = OPAL_PARAMETER;
break;
+ }
/* Check Supported ESL Type */
list = get_esl_signature_list(esl, eslvarsize);
diff --git a/libstb/secvar/test/secvar-test-edk2-compat.c b/libstb/secvar/test/secvar-test-edk2-compat.c
index ad1ceac..035e20a 100644
--- a/libstb/secvar/test/secvar-test-edk2-compat.c
+++ b/libstb/secvar/test/secvar-test-edk2-compat.c
@@ -166,6 +166,21 @@ int run_test()
ASSERT(5 == list_length(&variable_bank));
ASSERT(setup_mode);
+ /* Add PK with bad ESL. should fail since data is not big enough to be ESL*/
+ printf("Add PK with invalid appended ESL");
+ /* 1014 is length of appended ESL Header and its data */
+ tmp = new_secvar("PK", 3, PK_auth, PK_auth_len - 1014 + sizeof(EFI_SIGNATURE_LIST) - 1, 0);
+ ASSERT(0 == edk2_compat_validate(tmp));
+ list_add_tail(&update_bank, &tmp->link);
+ ASSERT(1 == list_length(&update_bank));
+ rc = edk2_compat_process(&variable_bank, &update_bank);
+ ASSERT(5 == list_length(&variable_bank));
+ ASSERT(0 == list_length(&update_bank));
+ rc = edk2_compat_post_process(&variable_bank, &update_bank);
+ ASSERT(5 == list_length(&variable_bank));
+ ASSERT(setup_mode);
+
+
/* Add PK to update and .process(). */
printf("Add PK");
tmp = new_secvar("PK", 3, PK_auth, PK_auth_len, 0);