(*mres)->pindex, *mres);
+		*mres = m;
+	}
+	m->valid = VM_PAGE_BITS_ALL;
+	return (VM_PAGER_OK);
+}
+
+static const struct cdev_pager_ops dsp_dev_pager_ops = {
+	.cdev_pg_ctor = dsp_dev_pager_ctor,
+	.cdev_pg_dtor = dsp_dev_pager_dtor,
+	.cdev_pg_fault = dsp_dev_pager_fault,
+};
+
+static int
+dsp_mmap_single(struct cdev *cdev, vm_ooffset_t *offset,
     vm_size_t size, struct vm_object **object, int nprot)
 {
+	struct dsp_mmap_handle *handle;
 	struct dsp_cdevpriv *priv;
 	struct snddev_info *d;
 	struct pcm_channel *wrch, *rdch, *c;
@@ -2011,13 +2058,18 @@ dsp_mmap_single(struct cdev *i_dev, vm_ooffset_t *offset,
 
 	*offset = (uintptr_t)sndbuf_getbufofs(c->bufsoft, *offset);
 	dsp_unlock_chans(priv, FREAD | FWRITE);
-	*object = vm_pager_allocate(OBJT_DEVICE, i_dev,
-	    size, nprot, *offset, curthread->td_ucred);
 
+	handle = malloc(sizeof(*handle), M_DEVBUF, M_WAITOK);
+	handle->cdev = cdev;
+	handle->buf = c->bufsoft;
+	*object = cdev_pager_allocate(handle, OBJT_DEVICE, &dsp_dev_pager_ops,
+	    size, nprot, *offset, curthread->td_ucred);
 	PCM_GIANT_LEAVE(d);
+	if (*object == NULL) {
+		free(handle, M_DEVBUF);
+		return (EINVAL);
+	}
 
-	if (*object == NULL)
-		 return (EINVAL);
 	return (0);
 }
 
diff --git a/tests/sys/sound/mmap.c b/tests/sys/sound/mmap.c
index ab203a39194c..f775c0f8da8a 100644
--- a/tests/sys/sound/mmap.c
+++ b/tests/sys/sound/mmap.c
@@ -4,12 +4,14 @@
  * Copyright (c) 2026 The FreeBSD Foundation
  */
 
+#include <sys/param.h>
 #include <sys/mman.h>
 #include <sys/soundcard.h>
 
 #include <atf-c.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <string.h>
 #include <unistd.h>
 
 #define	FMT_ERR(s)	s ": %s", strerror(errno)
@@ -43,9 +45,67 @@ ATF_TC_BODY(mmap_offset_overflow, tc)
 	close(fd);
 }
 
+/*
+ * Verify that a MAP_SHARED mapping of a DSP device's software buffer remains
+ * valid after the file descriptor is closed.
+ */
+ATF_TC(mmap_buffer_lifetime);
+ATF_TC_HEAD(mmap_buffer_lifetime, tc)
+{
+	atf_tc_set_md_var(tc, "descr", "mmap data survives close()");
+	atf_tc_set_md_var(tc, "require.kmods", "snd_dummy");
+}
+ATF_TC_BODY(mmap_buffer_lifetime, tc)
+{
+	audio_buf_info abi;
+	uint8_t *buf;
+	size_t len;
+	int fd, arg;
+
+	fd = open("/dev/dsp0", O_RDWR);
+	ATF_REQUIRE_MSG(fd >= 0, FMT_ERR("open"));
+
+	arg = (2 << 16) | 14; /* 2*16KB */
+	ATF_REQUIRE_MSG(ioctl(fd, SNDCTL_DSP_SETFRAGMENT, &arg) == 0,
+	    FMT_ERR("SNDCTL_DSP_SETFRAGMENT"));
+	ATF_REQUIRE_MSG(ioctl(fd, SNDCTL_DSP_GETOSPACE, &abi) == 0,
+	    FMT_ERR("SNDCTL_DSP_GETOSPACE"));
+
+	len = abi.bytes;
+	ATF_REQUIRE_MSG(len >= PAGE_SIZE, "buffer too small: %zu", len);
+
+	buf = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+	ATF_REQUIRE_MSG(buf != MAP_FAILED, FMT_ERR("mmap"));
+
+	for (size_t i = 0; i < len; i++) {
+		ATF_REQUIRE_MSG(buf[i] == 0,
+		    "mmap data corrupted at offset %zu: want 0 got 0x%02x",
+		    i, buf[i]);
+	}
+
+	memset(buf, 0xa5, len);
+	for (size_t i = 0; i < len; i++) {
+		ATF_REQUIRE_MSG(buf[i] == 0xa5,
+		    "mmap data corrupted at offset %zu: want 0xa5 got 0x%02x",
+		    i, buf[i]);
+	}
+
+	ATF_REQUIRE(close(fd) == 0);
+
+	/* Closing the device causes the buffer to be reset. */
+	for (size_t i = 0; i < len; i++) {
+		ATF_REQUIRE_MSG(buf[i] == 0 || buf[i] == 0xa5,
+		    "mmap data corrupted at offset %zu: got 0x%02x", i, buf[i]);
+	}
+	memset(buf, 0xa5, len);
+
+	ATF_REQUIRE(munmap(buf, len) == 0);
+}
+
 ATF_TP_ADD_TCS(tp)
 {
 	ATF_TP_ADD_TC(tp, mmap_offset_overflow);
+	ATF_TP_ADD_TC(tp, mmap_buffer_lifetime);
 
 	return (atf_no_error());
 }