Re: [bug report] xfs: Add xfs_has_attr and subroutines

[Allison Collins <allison.henderson@oracle.com>]

On 7/28/20 4:57 AM, dan.carpenter@oracle.com wrote:
> Hello Allison Collins,
> 
> The patch cfe3d8821c6f: "xfs: Add xfs_has_attr and subroutines" from
> Jul 20, 2020, leads to the following Smatch warning:
> 
> 	fs/xfs/libxfs/xfs_attr.c:1431 xfs_attr_node_get()
> 	warn: variable dereferenced before check 'state' (see line 1426)
> 
> fs/xfs/libxfs/xfs_attr.c
>    1398  STATIC int
>    1399  xfs_attr_node_get(
>    1400          struct xfs_da_args      *args)
>    1401  {
>    1402          struct xfs_da_state     *state;
>    1403          struct xfs_da_state_blk *blk;
>    1404          int                     i;
>    1405          int                     error;
>    1406
>    1407          trace_xfs_attr_node_get(args);
>    1408
>    1409          /*
>    1410           * Search to see if name exists, and get back a pointer to it.
>    1411           */
>    1412          error = xfs_attr_node_hasname(args, &state);
>    1413          if (error != -EEXIST)
>    1414                  goto out_release;
>                          ^^^^^^^^^^^^^^^^
> state can be NULL.
> 
>    1415
>    1416          /*
>    1417           * Get the value, local or "remote"
>    1418           */
>    1419          blk = &state->path.blk[state->path.active - 1];
>    1420          error = xfs_attr3_leaf_getvalue(blk->bp, args);
>    1421
>    1422          /*
>    1423           * If not in a transaction, we have to release all the buffers.
>    1424           */
>    1425  out_release:
>    1426          for (i = 0; i < state->path.active; i++) {
>                                  ^^^^^^^^^^^^^^^^^^
> Dereference
> 
>    1427                  xfs_trans_brelse(args->trans, state->path.blk[i].bp);
>    1428                  state->path.blk[i].bp = NULL;
>    1429          }
>    1430
>    1431          if (state)
>                      ^^^^^
> To late.
> 
>    1432                  xfs_da_state_free(state);
>    1433          return error;
>    1434  }
> 
> regards,
> dan carpenter
> 
Thanks for the catch, with send a patch for this

Allison