From: Yunxiang Li <Yunxiang.Li@xxxxxxx>
commit 4481913607e58196c48a4fef5e6f45350684ec3c upstream.
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: fee2ede15542 ("drm/ttm: rework bulk move handling v5")
Signed-off-by: Yunxiang Li <Yunxiang.Li@xxxxxxx>
Reviewed-by: Christian König <christian.koenig@xxxxxxx>
CC: stable@xxxxxxxxxxxxxxx
Link: https://patchwork.freedesktop.org/patch/msgid/20230622141902.28718-3-Yunxiang.Li@xxxxxxx
Signed-off-by: Christian König <christian.koenig@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/ttm/ttm_resource.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/ttm/ttm_resource.c
+++ b/drivers/gpu/drm/ttm/ttm_resource.c
@@ -85,6 +85,8 @@ static void ttm_lru_bulk_move_pos_tail(s
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;
}
@@ -110,7 +112,8 @@ static void ttm_lru_bulk_move_del(struct
{
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) {
