[PATCH V2] Fix 2 dc stream buffer

[PATCH V2] Fix 2 dc stream buffer

[Nigel Croxon]

To meet requirements of Common Criteria certification vulnerablility
assessment. Static code analysis has been run and found the following
Error: DC.STREAM_BUFFER (CWE-120): [#def46]
mdadm-4.2: dont_call: "fscanf" assumes an arbitrarily
long string, so callers must use correct precision specifiers or
never use "fscanf".

The change is to define a value for string %s.

V2: Tighten the value in policy.c to match the limit of the metadata.
Add a change to policy_save_path() to use correct precision on the
fscanf call.

Signed-off-by: Nigel Croxon <ncroxon@redhat.com>
---
 Monitor.c | 2 +-
 policy.c  | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/Monitor.c b/Monitor.c
index f541229..8bd3b5a 100644
--- a/Monitor.c
+++ b/Monitor.c
@@ -359,7 +359,7 @@ static int check_one_sharer(int scan)
 			 "/proc/%d/comm", pid);
 		comm_fp = fopen(comm_path, "r");
 		if (comm_fp) {
-			if (fscanf(comm_fp, "%s", comm) &&
+			if (fscanf(comm_fp, "%19s", comm) &&
 			    strncmp(basename(comm), Name, strlen(Name)) == 0) {
 				if (scan) {
 					pr_err("Only one autorebuild process allowed in scan mode, aborting\n");
diff --git a/policy.c b/policy.c
index 3c53bd3..eee9ef6 100644
--- a/policy.c
+++ b/policy.c
@@ -761,7 +761,7 @@ void policy_save_path(char *id_path, struct map_ent *array)
 		return;
 	}
 
-	if (fprintf(f, "%s %08x:%08x:%08x:%08x\n",
+	if (fprintf(f, "%20s %08x:%08x:%08x:%08x\n",
 		    array->metadata,
 		    array->uuid[0], array->uuid[1],
 		    array->uuid[2], array->uuid[3]) <= 0)
@@ -784,7 +784,7 @@ int policy_check_path(struct mdinfo *disk, struct map_ent *array)
 		if (!f)
 			continue;
 
-		rv = fscanf(f, " %s %x:%x:%x:%x\n",
+		rv = fscanf(f, " %20s %x:%x:%x:%x\n",
 			    array->metadata,
 			    array->uuid,
 			    array->uuid+1,
-- 
2.29.2

Re: [PATCH V2] Fix 2 dc stream buffer

[Jes Sorensen]

On 10/14/21 12:02 PM, Nigel Croxon wrote:
> To meet requirements of Common Criteria certification vulnerablility
> assessment. Static code analysis has been run and found the following
> Error: DC.STREAM_BUFFER (CWE-120): [#def46]
> mdadm-4.2: dont_call: "fscanf" assumes an arbitrarily
> long string, so callers must use correct precision specifiers or
> never use "fscanf".
> 
> The change is to define a value for string %s.
> 
> V2: Tighten the value in policy.c to match the limit of the metadata.
> Add a change to policy_save_path() to use correct precision on the
> fscanf call.
> 
> Signed-off-by: Nigel Croxon <ncroxon@redhat.com>
> ---
>  Monitor.c | 2 +-
>  policy.c  | 4 ++--
>  2 files changed, 3 insertions(+), 3 deletions(-)

Applied

Thanks
Jes