diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c
--- a/sys/kern/vfs_vnops.c
+++ b/sys/kern/vfs_vnops.c
@@ -3143,7 +3143,7 @@
 		rem = *inoffp % blksize;
 		if (rem > 0)
 			rem = blksize - rem;
-		if (len - rem > blksize)
+		if (len > rem && len - rem > blksize)
 			len = savlen = rounddown(len - rem, blksize) + rem;
 	}