[PATCH 3.18 043/150] UBI: Fix double free after do_sync_erase()

Greg Kroah-Hartman
2015-01-14T07:26:13Z

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/mtd/ubi/wl.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)

--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -1212,7 +1212,6 @@ static int wear_leveling_worker(struct u

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;
@@ -1226,10 +1225,8 @@ static int wear_leveling_worker(struct u
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");
@@ -1265,10 +1262,9 @@ 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;