diff --git a/test/initramfs/src/apps/file_io/file_err.c b/test/initramfs/src/apps/file_io/file_err.c
new file mode 100644
index 000000000..1f4cd32b0
--- /dev/null
+++ b/test/initramfs/src/apps/file_io/file_err.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: MPL-2.0
+
+#define _GNU_SOURCE
+
+#include "../test.h"
+#include <stdint.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+
+static int fd;
+
+FN_SETUP(open)
+{
+	fd = CHECK(open("/etc/passwd", O_RDONLY));
+}
+END_SETUP()
+
+FN_TEST(dup_out_of_range)
+{
+	// `-1` is out of the allowed range for file descriptors.
+	TEST_ERRNO(dup2(fd, -1), EBADF);
+}
+END_TEST()
+
+FN_TEST(flock_overflow)
+{
+	struct flock fl;
+
+	fl.l_type = F_RDLCK;
+	fl.l_whence = SEEK_SET;
+
+	// `l_start + l_len` underflows.
+	fl.l_start = -1;
+	fl.l_len = INT64_MIN;
+	TEST_ERRNO(fcntl(fd, F_SETLK, &fl), EINVAL);
+
+	// `l_start + l_len` overflows.
+	fl.l_start = 2;
+	fl.l_len = INT64_MAX;
+	TEST_ERRNO(fcntl(fd, F_SETLK, &fl), EOVERFLOW);
+}
+END_TEST()
+
+FN_TEST(ftruncate_large)
+{
+	int memfd;
+
+	memfd = TEST_SUCC(memfd_create("test_memfd", 0));
+
+	// `ftruncate` can handle large expansions and shrinking.
+	TEST_SUCC(ftruncate(memfd, ((off_t)1) << 50));
+	TEST_SUCC(ftruncate(memfd, 0));
+
+	TEST_SUCC(close(memfd));
+}
+END_TEST()
+
+FN_SETUP(cleanup)
+{
+	CHECK(close(fd));
+}
+END_SETUP()
diff --git a/test/initramfs/src/apps/mmap/mmap_err.c b/test/initramfs/src/apps/mmap/mmap_err.c
index 695019c6d..b285eaf83 100644
--- a/test/initramfs/src/apps/mmap/mmap_err.c
+++ b/test/initramfs/src/apps/mmap/mmap_err.c
@@ -32,7 +32,11 @@ FN_TEST(overflow_len)
 			MAP_PRIVATE | MAP_ANONYMOUS, 0, 0),
 		   ENOMEM);
 	TEST_ERRNO(mremap(valid_addr, ~(size_t)1, PAGE_SIZE, 0), EINVAL);
+	TEST_ERRNO(mremap(valid_addr, ~(size_t)1, PAGE_SIZE, MREMAP_MAYMOVE),
+		   EINVAL);
 	TEST_ERRNO(mremap(valid_addr, PAGE_SIZE, ~(size_t)1, 0), EINVAL);
+	TEST_ERRNO(mremap(valid_addr, PAGE_SIZE, ~(size_t)1, MREMAP_MAYMOVE),
+		   EINVAL);
 	TEST_ERRNO(munmap(valid_addr, ~(size_t)1), EINVAL);
 	TEST_ERRNO(mprotect(valid_addr, ~(size_t)1, PROT_READ), ENOMEM);
 	TEST_ERRNO(madvise(valid_addr, ~(size_t)1, MADV_NORMAL), EINVAL);
@@ -52,7 +56,9 @@ FN_TEST(zero_len)
 			0, 0),
 		   EINVAL);
 	TEST_ERRNO(mremap(valid_addr, 0, PAGE_SIZE, 0), EINVAL);
+	TEST_ERRNO(mremap(valid_addr, 0, PAGE_SIZE, MREMAP_MAYMOVE), EINVAL);
 	TEST_ERRNO(mremap(valid_addr, PAGE_SIZE, 0, 0), EINVAL);
+	TEST_ERRNO(mremap(valid_addr, PAGE_SIZE, 0, MREMAP_MAYMOVE), EINVAL);
 	TEST_ERRNO(munmap(valid_addr, 0), EINVAL);
 	TEST_SUCC(mprotect(valid_addr, 0, PROT_READ));
 	TEST_SUCC(madvise(valid_addr, 0, MADV_NORMAL));
@@ -71,7 +77,18 @@ FN_TEST(overflow_addr)
 				MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, 0, 0),
 			   ENOMEM);
 		TEST_ERRNO(mremap(valid_addr, len, PAGE_SIZE, 0), EINVAL);
+		TEST_ERRNO(mremap(valid_addr, len, PAGE_SIZE, MREMAP_MAYMOVE),
+			   EINVAL);
 		TEST_ERRNO(mremap(valid_addr, PAGE_SIZE, len, 0), EINVAL);
+		// FIXME: Asterinas will return `ENOMEM` in this test, which differs
+		// from Linux's error code.
+#ifdef __asterinas__
+		TEST_ERRNO(mremap(valid_addr, PAGE_SIZE, len, MREMAP_MAYMOVE),
+			   ENOMEM);
+#else
+		TEST_ERRNO(mremap(valid_addr, PAGE_SIZE, len, MREMAP_MAYMOVE),
+			   EINVAL);
+#endif
 		TEST_ERRNO(munmap(valid_addr, len), EINVAL);
 		TEST_ERRNO(mprotect(valid_addr, len, PROT_READ), ENOMEM);
 		TEST_ERRNO(madvise(valid_addr, len, MADV_NORMAL), EINVAL);
@@ -88,6 +105,7 @@ FN_TEST(underflow_addr)
 			MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, 0, 0),
 		   EPERM);
 	TEST_ERRNO(mremap(addr, PAGE_SIZE, PAGE_SIZE, 0), EFAULT);
+	TEST_ERRNO(mremap(addr, PAGE_SIZE, PAGE_SIZE, MREMAP_MAYMOVE), EFAULT);
 	TEST_ERRNO(mremap(valid_addr, PAGE_SIZE, PAGE_SIZE, MREMAP_FIXED, addr),
 		   EINVAL);
 	TEST_SUCC(munmap(addr, PAGE_SIZE));
@@ -103,6 +121,8 @@ FN_TEST(unaligned_addr)
 			MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, 0, 0),
 		   EINVAL);
 	TEST_ERRNO(mremap(valid_addr + 1, PAGE_SIZE, PAGE_SIZE, 0), EINVAL);
+	TEST_ERRNO(mremap(valid_addr + 1, PAGE_SIZE, PAGE_SIZE, MREMAP_MAYMOVE),
+		   EINVAL);
 	TEST_ERRNO(mremap(valid_addr, PAGE_SIZE, PAGE_SIZE, MREMAP_FIXED,
 			  valid_addr + 1),
 		   EINVAL);
diff --git a/test/initramfs/src/apps/scripts/fs.sh b/test/initramfs/src/apps/scripts/fs.sh
index 6e0a83358..618b8370e 100755
--- a/test/initramfs/src/apps/scripts/fs.sh
+++ b/test/initramfs/src/apps/scripts/fs.sh
@@ -105,6 +105,7 @@ pipe/short_rw
 epoll/epoll_err
 epoll/poll_err
 file_io/access_err
+file_io/file_err
 file_io/iovec_err
 devfs/full
 devfs/random