diff options
| author | Zhihao Cheng <chengzhihao1@huawei.com> | 2022-07-30 19:28:37 +0800 |
|---|---|---|
| committer | Richard Weinberger <richard@nod.at> | 2023-02-02 21:13:50 +0100 |
| commit | a240bc5c43130c6aa50831d7caaa02a1d84e1bce (patch) | |
| tree | c4c6475c1b57f85d20de3a1dcdc367e7ede0eae5 /drivers/mtd/ubi | |
| parent | 76f9476ece445a07aeb72df9d896cd563fb5b50f (diff) | |
| download | linux-a240bc5c43130c6aa50831d7caaa02a1d84e1bce.tar.gz | |
ubi: Fix UAF wear-leveling entry in eraseblk_count_seq_show()
Wear-leveling entry could be freed in error path, which may be accessed
again in eraseblk_count_seq_show(), for example:
__erase_worker eraseblk_count_seq_show
wl = ubi->lookuptbl[*block_number]
if (wl)
wl_entry_destroy
ubi->lookuptbl[e->pnum] = NULL
kmem_cache_free(ubi_wl_entry_slab, e)
erase_count = wl->ec // UAF!
Wear-leveling entry updating/accessing in ubi->lookuptbl should be
protected by ubi->wl_lock, fix it by adding ubi->wl_lock to serialize
wl entry accessing between wl_entry_destroy() and
eraseblk_count_seq_show().
Fetch a reproducer in [Link].
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216305
Fixes: 7bccd12d27b7e3 ("ubi: Add debugfs file for tracking PEB state")
Fixes: 801c135ce73d5d ("UBI: Unsorted Block Images")
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'drivers/mtd/ubi')
| -rw-r--r-- | drivers/mtd/ubi/wl.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c index 68eb0f21b3fe..f45df3b77373 100644 --- a/drivers/mtd/ubi/wl.c +++ b/drivers/mtd/ubi/wl.c @@ -890,8 +890,11 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk, err = do_sync_erase(ubi, e1, vol_id, lnum, 0); if (err) { - if (e2) + if (e2) { + spin_lock(&ubi->wl_lock); wl_entry_destroy(ubi, e2); + spin_unlock(&ubi->wl_lock); + } goto out_ro; } @@ -1130,14 +1133,18 @@ static int __erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk) /* Re-schedule the LEB for erasure */ err1 = schedule_erase(ubi, e, vol_id, lnum, 0, false); if (err1) { + spin_lock(&ubi->wl_lock); wl_entry_destroy(ubi, e); + spin_unlock(&ubi->wl_lock); err = err1; goto out_ro; } return err; } + spin_lock(&ubi->wl_lock); wl_entry_destroy(ubi, e); + spin_unlock(&ubi->wl_lock); if (err != -EIO) /* * If this is not %-EIO, we have no idea what to do. Scheduling |