Re: [Cluster-devel] [BUG] fs: gfs2: possible null-pointer dereferences in gfs2_rgrp_bh_get()

[Jia-Ju Bai]

Thanks for the reply :)

On 2019/7/24 17:04, Steven Whitehouse wrote:
> Hi,
>
> On 24/07/2019 09:50, Jia-Ju Bai wrote:
> > In gfs2_rgrp_bh_get, there is an if statement on line 1191 to check 
> > whether "rgd->rd_bits[0].bi_bh" is NULL.
>
> That is how we detect whether the rgrp has already been read in, so 
> the function is skipped in the case that we've already read in the rgrp.
>
>
> > When "rgd->rd_bits[0].bi_bh" is NULL, it is used on line 1216:
> > ÂÂÂ gfs2_rgrp_in(rgd, (rgd->rd_bits[0].bi_bh)->b_data);
>
> No it isn't. See line 1196 where bi_bh is set, and where we also bail 
> out (line 1198) in case it has not been set.

I overlooked the operation on line 1196...
Thanks for the pointer, I am sorry for the false report...


Best wishes,
Jia-Ju Bai