On Mon, Oct 22, 2018 at 11:04:31PM -0500, Eric Sandeen wrote:
> If we need to realloc the bplist[] array holding buffers for a given
> directory, we don't initialize the new slots. This causes a problem
> if the directory has holes, because those slots never get filled in.
>
> At the end of the function we call libxfs_putbuf for every non-null
> slot, and any uninitialized slots are segfault landmines.
>
> Make sure we initialize all new slots to NULL for this reason.
>
> Reported-by: Oleg Davydov <burunduk3@xxxxxxxxx>
> Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
Yay realloc :P
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
--D
> ---
>
> diff --git a/repair/phase6.c b/repair/phase6.c
> index b87c751..9d24a4f 100644
> --- a/repair/phase6.c
> +++ b/repair/phase6.c
> @@ -2348,6 +2348,8 @@ longform_dir2_entry_check(xfs_mount_t *mp,
>
> db = xfs_dir2_da_to_db(mp->m_dir_geo, da_bno);
> if (db >= num_bps) {
> + int last_size = num_bps;
> +
> /* more data blocks than expected */
> num_bps = db + 1;
> bplist = realloc(bplist, num_bps * sizeof(struct xfs_buf*));
> @@ -2355,6 +2357,9 @@ longform_dir2_entry_check(xfs_mount_t *mp,
> do_error(_("realloc failed in %s (%zu bytes)\n"),
> __func__,
> num_bps * sizeof(struct xfs_buf*));
> + /* Initialize the new elements */
> + for (i = last_size; i < num_bps; i++)
> + bplist[i] = NULL;
> }
>
> if (isblock)
>
