From: Zhihao Cheng chengzhihao1@huawei.com
[ Upstream commit 8c03a1c21d72210f81cb369cc528e3fde4b45411 ]
There is an use-after-free problem for 'eba_tbl' in ubi_create_volume()'s error handling path:
ubi_eba_replace_table(vol, eba_tbl) vol->eba_tbl = tbl out_mapping: ubi_eba_destroy_table(eba_tbl) // Free 'eba_tbl' out_unlock: put_device(&vol->dev) vol_release kfree(tbl->entries) // UAF
Fix it by removing redundant 'eba_tbl' releasing. Fetch a reproducer in [Link].
Fixes: 493cfaeaa0c9b ("mtd: utilize new cdev_device_add helper function") Link: https://bugzilla.kernel.org/show_bug.cgi?id=215965 Signed-off-by: Zhihao Cheng chengzhihao1@huawei.com Signed-off-by: Richard Weinberger richard@nod.at Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/mtd/ubi/vmt.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c index d0c6b66b7450..9f6ffd340a3e 100644 --- a/drivers/mtd/ubi/vmt.c +++ b/drivers/mtd/ubi/vmt.c @@ -322,7 +322,6 @@ int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req) ubi->volumes[vol_id] = NULL; ubi->vol_count -= 1; spin_unlock(&ubi->volumes_lock); - ubi_eba_destroy_table(eba_tbl); out_acc: spin_lock(&ubi->volumes_lock); ubi->rsvd_pebs -= vol->reserved_pebs;