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| author | Zhihao Cheng <chengzhihao1@huawei.com> | 2022-07-30 19:28:37 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-11 16:26:51 +0100 |
| commit | 3f9b63dfce44a7c3c095dd93d910408e07ab1845 (patch) | |
| tree | 59fb727440427dce7b7a40e4ae0e650d6e733b52 | |
| parent | 44071bcf914c34f34a0112421b9735eaa72da179 (diff) | |
| download | linux-3f9b63dfce44a7c3c095dd93d910408e07ab1845.tar.gz linux-3f9b63dfce44a7c3c095dd93d910408e07ab1845.tar.bz2 linux-3f9b63dfce44a7c3c095dd93d910408e07ab1845.zip | |
ubi: Fix UAF wear-leveling entry in eraseblk_count_seq_show()
[ Upstream commit a240bc5c43130c6aa50831d7caaa02a1d84e1bce ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -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 545a92eb8f56..e267e0519d94 100644 --- a/drivers/mtd/ubi/wl.c +++ b/drivers/mtd/ubi/wl.c @@ -878,8 +878,11 @@ 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; } @@ -1103,14 +1106,18 @@ 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 |