[nfs-utils PATCH] fsidd: replace assertions with explicit malformed-input handling

[nfs-utils PATCH] fsidd: replace assertions with explicit malformed-input handling

[Scott Mayhew]

fsidd relies on assert() to ensure that an argument is present after the
command prefix while parsing commands received over the local socket.
Malformed input can cause fsidd to abort.  Replace the assertions with
explicit malformed-input handling and return an error to the client.

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
---
 support/reexport/fsidd.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/support/reexport/fsidd.c b/support/reexport/fsidd.c
index 51750ea3..f5c397aa 100644
--- a/support/reexport/fsidd.c
+++ b/support/reexport/fsidd.c
@@ -48,7 +48,11 @@ static void client_cb(evutil_socket_t cl, short ev, void *d)
 		char *answer = NULL;
 		bool found;
 
-		assert(req_path < buf + n );
+		if (req_path >= buf + n) {
+			char answer[] = "- Command failed: Bad input";
+			(void)send(cl, answer, strlen(answer), 0);
+			return;
+		}
 
 		printf("client asks for %s\n", req_path);
 
@@ -70,8 +74,11 @@ static void client_cb(evutil_socket_t cl, short ev, void *d)
 		char *answer = NULL;
 		bool found;
 
-		assert(req_path < buf + n );
-
+		if (req_path >= buf + n) {
+			char answer[] = "- Command failed: Bad input";
+			(void)send(cl, answer, strlen(answer), 0);
+			return;
+		}
 
 		if (dbbackend->fsidnum_by_path(req_path, &fsidnum, true, &found)) {
 			if (found) {
@@ -94,7 +101,11 @@ static void client_cb(evutil_socket_t cl, short ev, void *d)
 		uint32_t fsidnum;
 		bool found;
 
-		assert(req_fsidnum < buf + n );
+		if (req_fsidnum >= buf + n) {
+			char answer[] = "- Command failed: Bad input";
+			(void)send(cl, answer, strlen(answer), 0);
+			return;
+		}
 
 		errno = 0;
 		fsidnum = strtoul(req_fsidnum, &endp, 10);
-- 
2.55.0

Re: [nfs-utils PATCH] fsidd: replace assertions with explicit malformed-input handling

[Steve Dickson]

On 9/3/26 1:48 PM, Scott Mayhew wrote:
> fsidd relies on assert() to ensure that an argument is present after the
> command prefix while parsing commands received over the local socket.
> Malformed input can cause fsidd to abort.  Replace the assertions with
> explicit malformed-input handling and return an error to the client.
> 
> Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Committed... (tag: nfs-utils-2-9-3-rc4)

steved.
> ---
>   support/reexport/fsidd.c | 19 +++++++++++++++----
>   1 file changed, 15 insertions(+), 4 deletions(-)
> 
> diff --git a/support/reexport/fsidd.c b/support/reexport/fsidd.c
> index 51750ea3..f5c397aa 100644
> --- a/support/reexport/fsidd.c
> +++ b/support/reexport/fsidd.c
> @@ -48,7 +48,11 @@ static void client_cb(evutil_socket_t cl, short ev, void *d)
>   		char *answer = NULL;
>   		bool found;
>   
> -		assert(req_path < buf + n );
> +		if (req_path >= buf + n) {
> +			char answer[] = "- Command failed: Bad input";
> +			(void)send(cl, answer, strlen(answer), 0);
> +			return;
> +		}
>   
>   		printf("client asks for %s\n", req_path);
>   
> @@ -70,8 +74,11 @@ static void client_cb(evutil_socket_t cl, short ev, void *d)
>   		char *answer = NULL;
>   		bool found;
>   
> -		assert(req_path < buf + n );
> -
> +		if (req_path >= buf + n) {
> +			char answer[] = "- Command failed: Bad input";
> +			(void)send(cl, answer, strlen(answer), 0);
> +			return;
> +		}
>   
>   		if (dbbackend->fsidnum_by_path(req_path, &fsidnum, true, &found)) {
>   			if (found) {
> @@ -94,7 +101,11 @@ static void client_cb(evutil_socket_t cl, short ev, void *d)
>   		uint32_t fsidnum;
>   		bool found;
>   
> -		assert(req_fsidnum < buf + n );
> +		if (req_fsidnum >= buf + n) {
> +			char answer[] = "- Command failed: Bad input";
> +			(void)send(cl, answer, strlen(answer), 0);
> +			return;
> +		}
>   
>   		errno = 0;
>   		fsidnum = strtoul(req_fsidnum, &endp, 10);