This is a note to let you know that I've just added the patch titled
ubi: ubi_create_volume: Fix use-after-free when volume creation failed
to the 5.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ubi-ubi_create_volume-fix-use-after-free-when-volume.patch
and it can be found in the queue-5.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 0c27c6f1861e1b7cb239050db4621dccba36e787
Author: Zhihao Cheng <chengzhihao1@xxxxxxxxxx>
Date: Tue May 10 20:31:26 2022 +0800
ubi: ubi_create_volume: Fix use-after-free when volume creation failed
[ 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@xxxxxxxxxx>
Signed-off-by: Richard Weinberger <richard@xxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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;
