From: James Jones <jejones3141@gmail.com>
Date: Sun, 12 Jan 2025 20:49:14 +0000 (-0600)
Subject: Annotate return_overflow in fr_writev() (CID #1604625) (#5438)
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f5010cbe05848d0308a99f9fcac33d48dcbd0e8d;p=thirdparty%2Ffreeradius-server.git

Annotate return_overflow in fr_writev() (CID #1604625) (#5438)

In theory, iovcnt and the amounts written could total to more than
SSIZE_MAX, and when Coverity is looking at fr_writev() rather than
its callers it can't tell. We therefore annotate.
---

diff --git a/src/lib/util/iovec.c b/src/lib/util/iovec.c
index ce65a28ed43..acbbb1cdc60 100644
--- a/src/lib/util/iovec.c
+++ b/src/lib/util/iovec.c
@@ -75,13 +75,6 @@ ssize_t fr_writev(int fd, struct iovec vector[], int iovcnt, fr_time_delta_t tim
 
 		wrote = writev(fd, vector_p, iovcnt);
 		if (wrote > 0) {
-#ifdef __COVERITY__
-			/*
-			 * 	Coverity thinks that total += wrote might underflow,
-			 * 	which causes an issue at the return.
-			 */
-			if (total + wrote < total) return -1;
-#endif
 			total += wrote;
 			while (wrote > 0) {
 				/*
@@ -102,7 +95,10 @@ ssize_t fr_writev(int fd, struct iovec vector[], int iovcnt, fr_time_delta_t tim
 				break;
 			}
 			continue;
-		} else if (wrote == 0) return total;
+		} else if (wrote == 0) {
+			/* coverity[return_overflow] */
+			return total;
+		}
 
 		switch (errno) {
 		/* Write operation would block, use select() to implement a timeout */