[Samba] Coredump when copying .docx file (4.15.1)

[Jeremy Allison]

On Mon, Nov 01, 2021 at 09:38:07PM +0100, Sen Haerens via samba wrote:
>I'm copying from a Macbook (Big Sur 11.6) to an Arch Linux system (kernel
>5.14.15), tested with Samba 4.15 and 4.15.1.
>
>The copying hangs on the client and the share is unmounted. After
>remounting the share it appears the file has been successfully copied. I do
>not have access to Bugzilla, so posting here.
>
>Here is the backtrace:
>https://gist.github.com/SenH/2a611b30b8ed9ef7c234b7d14d75d074

Are you able to rebuild Samba ? If so, I think this may
be the fix:

diff --git a/source3/lib/adouble.c b/source3/lib/adouble.c
index fd435b6592d..854c239963b 100644
--- a/source3/lib/adouble.c
+++ b/source3/lib/adouble.c
@@ -2592,8 +2592,7 @@ int ad_fset(struct vfs_handle_struct *handle,
  	DBG_DEBUG("Path [%s]\n", fsp_str_dbg(fsp));
  
  	if ((fsp == NULL)
-	    || (fsp->fh == NULL)
-	    || (fsp_get_io_fd(fsp) == -1))
+	    || (fsp->fh == NULL))
  	{
  		smb_panic("bad fsp");
  	}
@@ -2612,6 +2611,9 @@ int ad_fset(struct vfs_handle_struct *handle,
  				   AD_DATASZ_XATTR, 0);
  		break;
  	case ADOUBLE_RSRC:
+		if (fsp_get_io_fd(fsp) == -1) {
+			smb_panic("bad fsp for ADOUBLE_RSRC");
+		}
  		len = SMB_VFS_NEXT_PWRITE(handle,
  					  fsp,
  					  ad->ad_data,