| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.17 091/298] ubi: ubi_create_volume: Fix use-after-free when volume creation failed | Date | Mon, 13 Jun 2022 12:09:45 +0200 |
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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 1bc7b3a05604..6ea95ade4ca6 100644 --- a/drivers/mtd/ubi/vmt.c +++ b/drivers/mtd/ubi/vmt.c @@ -309,7 +309,6 @@ 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; -- 2.35.1
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