From a32079ce17899192a7b98a42753be467605a8b2f Mon Sep 17 00:00:00 2001 From: Jonathan Brassow Date: Thu, 2 Apr 2009 19:55:35 +0100 Subject: [PATCH] dm snapshot: persistent fix dtr cleanup The persistent exception store destructor does not properly account for all conditions in which it can be called. If it is called after 'ctr' but before 'read_metadata' (e.g. if something else in 'snapshot_ctr' fails) then it will attempt to free areas of memory that haven't been allocated yet. Signed-off-by: Jonathan Brassow Signed-off-by: Alasdair G Kergon --- drivers/md/dm-snap-persistent.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/drivers/md/dm-snap-persistent.c b/drivers/md/dm-snap-persistent.c index 1799205cd945..e75c6dd76a9a 100644 --- a/drivers/md/dm-snap-persistent.c +++ b/drivers/md/dm-snap-persistent.c @@ -162,9 +162,12 @@ static int alloc_area(struct pstore *ps) static void free_area(struct pstore *ps) { - vfree(ps->area); + if (ps->area) + vfree(ps->area); ps->area = NULL; - vfree(ps->zero_area); + + if (ps->zero_area) + vfree(ps->zero_area); ps->zero_area = NULL; } @@ -482,9 +485,16 @@ static void persistent_dtr(struct dm_exception_store *store) struct pstore *ps = get_info(store); destroy_workqueue(ps->metadata_wq); - dm_io_client_destroy(ps->io_client); - vfree(ps->callbacks); + + /* Created in read_header */ + if (ps->io_client) + dm_io_client_destroy(ps->io_client); free_area(ps); + + /* Allocated in persistent_read_metadata */ + if (ps->callbacks) + vfree(ps->callbacks); + kfree(ps); } @@ -661,7 +671,7 @@ static int persistent_ctr(struct dm_exception_store *store, struct pstore *ps; /* allocate the pstore */ - ps = kmalloc(sizeof(*ps), GFP_KERNEL); + ps = kzalloc(sizeof(*ps), GFP_KERNEL); if (!ps) return -ENOMEM;