Commit 44819136 authored by Yunxiang Li's avatar Yunxiang Li Committed by Christian König
Browse files

drm/ttm: fix bulk_move corruption when adding a entry 



When the resource is the first in the bulk_move range, adding it again
(thus moving it to the tail) will corrupt the list since the first
pointer is not moved. This eventually lead to null pointer deref in
ttm_lru_bulk_move_del()

Fixes: fee2ede1 ("drm/ttm: rework bulk move handling v5")
Signed-off-by: default avatarYunxiang Li <Yunxiang.Li@amd.com>
Reviewed-by: default avatarChristian König <christian.koenig@amd.com>
CC: stable@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20230622141902.28718-3-Yunxiang.Li@amd.com


Signed-off-by: default avatarChristian König <christian.koenig@amd.com>
parent 98703e4e

drivers/gpu/drm/ttm/ttm_resource.c

+4 −1
Original line number Diff line number Diff line
@@ -86,6 +86,8 @@ static void ttm_lru_bulk_move_pos_tail(struct ttm_lru_bulk_move_pos *pos, 
				       struct ttm_resource *res)

{

	if (pos->last != res) {

		if (pos->first == res)

			pos->first = list_next_entry(res, lru);

		list_move(&res->lru, &pos->last->lru);

		pos->last = res;

	}
@@ -111,7 +113,8 @@ static void ttm_lru_bulk_move_del(struct ttm_lru_bulk_move *bulk, 
{

	struct ttm_lru_bulk_move_pos *pos = ttm_lru_bulk_move_pos(bulk, res);



	if (unlikely(pos->first == res && pos->last == res)) {

	if (unlikely(WARN_ON(!pos->first || !pos->last) ||

		     pos->first == res && pos->last == res)) {

		pos->first = NULL;

		pos->last = NULL;

	} else if (pos->first == res) {