zfs: Merge commit 86b064469dc9c2 from OpenZFSHEADmain

  FreeBSD: Fix a potential null dereference in zfs_freebsd_fsync()

  In general it's possible for a vnode to not have an associated VM
  object.  This happens in particular with named pipes, which have
  some distinct VOPs, defined in zfs_fifoops.  Thus, this chunk of
  zfs_freebsd_fsync() needs to check for the FIFO case, like other
  vm_object_mightbedirty() callers do.

  (Note that vn_flush_cached_data() calls are predicated on
  zn_has_cached_data() returning true, and it checks for a NULL v_object
  pointer already.)

  Fixes: ef4058fcdc01838117dd93a654228bac7487a37c
  Reported-by: Collin Funk <collin.funk1@gmail.com>
  Reviewed-by: Sean Eric Fagan <sef@FreeBSD.org>
  Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
  Reviewed-by: Alexander Motin <alexander.motin@TrueNAS.com>
  Signed-off-by: Mark Johnston <markj@FreeBSD.org>
  Closes #18015

MFC after:	3 days

1 files changed, 1 insertions, 1 deletions

diff --git a/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_vnops_os.c b/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_vnops_os.c
index 8a9d23d0d554..05ac77741d4f 100644
--- a/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_vnops_os.c
+++ b/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_vnops_os.c
@@ -5275,7 +5275,7 @@ zfs_freebsd_fsync(struct vop_fsync_args *ap)
 	 * Push any dirty mmap()'d data out to the DMU and ZIL, ready for
 	 * zil_commit() to be called in zfs_fsync().
 	 */
-	if (vm_object_mightbedirty(vp->v_object)) {
+	if (vp->v_object != NULL && vm_object_mightbedirty(vp->v_object)) {
 		zfs_vmobject_wlock(vp->v_object);
 		if (!vm_object_page_clean(vp->v_object, 0, 0, 0))
 			err = SET_ERROR(EIO);