On 09/08, Bill Wendling wrote: > > We can add the __counted_by_ptr attribute to the 'forward' and 'reverse' > pointer fields of 'struct uid_gid_map', which are counted by > 'nr_extents'.
Since I am CC'ed again... (thanks btw) Personally, I am not a huge fan of __counted_by_ptr, at least in this particular case. But 1/2 looks technically correct, I think it doesn't hurt ;) So, FWIW Reviewed-by: Oleg Nesterov <[email protected]> > --- a/kernel/user_namespace.c > +++ b/kernel/user_namespace.c > @@ -809,13 +809,17 @@ static int insert_extent(struct uid_gid_map *map, > struct uid_gid_extent *extent) > map->reverse = NULL; > } > > - if (map->nr_extents < UID_GID_MAP_MAX_BASE_EXTENTS) > - dest = &map->extent[map->nr_extents]; > + /* > + * nr_extents must be updated before the extent and forward arrays are > + * accessed, otherwise KSAN will assert an out-of-bounds error. > + */ > + map->nr_extents++; Yes, but perhaps the comment should be more explicit... I mean, something like ... otherwise KSAN ... because of __counted_by_ptr(nr_extents) Nevermind, this is just a minor/subjective nit. Oleg.
