[PATCH 3.16.y-ckt 019/216] UBI: Fix double free after do_sync_erase()

Luis Henriques
2015-01-12T19:14:58Z

From: Richard Weinberger <richard@nod.at>

commit aa5ad3b6eb8feb2399a5d26c8fb0060561bb9534 upstream.

If the erase worker is unable to erase a PEB it will
free the ubi_wl_entry itself.
The failing ubi_wl_entry must not free()'d again after
do_sync_erase() returns.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
drivers/mtd/ubi/wl.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index 0f3425dac910..89d51f94db11 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -1211,7 +1211,6 @@ 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) {
- kmem_cache_free(ubi_wl_entry_slab, e1);
if (e2)
kmem_cache_free(ubi_wl_entry_slab, e2);
goto out_ro;
@@ -1225,10 +1224,8 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
dbg_wl("PEB %d (LEB %d:%d) was put meanwhile, erase",
e2->pnum, vol_id, lnum);
err = do_sync_erase(ubi, e2, vol_id, lnum, 0);
- if (err) {
- kmem_cache_free(ubi_wl_entry_slab, e2);
+ if (err)
goto out_ro;
- }
}

dbg_wl("done");
@@ -1264,10 +1261,9 @@ out_not_moved:

ubi_free_vid_hdr(ubi, vid_hdr);
err = do_sync_erase(ubi, e2, vol_id, lnum, torture);
- if (err) {
- kmem_cache_free(ubi_wl_entry_slab, e2);
+ if (err)
goto out_ro;
- }
+
mutex_unlock(&ubi->move_mutex);
return 0;

--
2.1.4