Re: [PATCH 1/1] bfa: Fixes for 0-terminated strncpy and possiblenull pointer dereference

From: James Bottomley
Date: Wed Jun 26 2013 - 11:37:39 EST


On Wed, 2013-05-15 at 21:41 +0200, Jakob Normark wrote:
> This patch fixes two cppcheck errors in drivers/scsi/bfa/bfad_im.c
>
> Signed-off-by: Jakob Normark <jakobnormark@xxxxxxxxx>
> ---
> drivers/scsi/bfa/bfad_im.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/scsi/bfa/bfad_im.c b/drivers/scsi/bfa/bfad_im.c
> index 5864f98..9489c56 100644
> --- a/drivers/scsi/bfa/bfad_im.c
> +++ b/drivers/scsi/bfa/bfad_im.c
> @@ -944,13 +944,15 @@ static int
> bfad_im_slave_alloc(struct scsi_device *sdev)
> {
> struct fc_rport *rport = starget_to_rport(scsi_target(sdev));
> - struct bfad_itnim_data_s *itnim_data =
> - (struct bfad_itnim_data_s *) rport->dd_data;
> - struct bfa_s *bfa = itnim_data->itnim->bfa_itnim->bfa;
> + struct bfad_itnim_data_s *itnim_data;
> + struct bfa_s *bfa;
>
> if (!rport || fc_remote_port_chkready(rport))
> return -ENXIO;
>
> + itnim_data = (struct bfad_itnim_data_s *) rport->dd_data;
> + bfa = itnim_data->itnim->bfa_itnim->bfa;
> +
> if (bfa_get_lun_mask_status(bfa) == BFA_LUNMASK_ENABLED) {
> /*
> * We should not mask LUN 0 - since this will translate
> @@ -1037,6 +1039,7 @@ bfad_fc_host_init(struct bfad_im_port_s *im_port)
>
> strncpy(symname, bfad->bfa_fcs.fabric.bport.port_cfg.sym_name.symname,
> BFA_SYMNAME_MAXLEN);
> + symname[BFA_SYMNAME_MAXLEN - 1] = '\0';

This isn't correct, it's effectively a handrolled version of strlcpy.
The correct fix is to replace strncpy with strlcpy. I fixed it up in
the patch version.

James


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