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dm snapshot: persistent fix dtr cleanup

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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 <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This commit is contained in:
Jonathan Brassow 2009-04-02 19:55:35 +01:00 committed by Alasdair G Kergon
parent 1e302a929e
commit a32079ce17
1 changed files with 15 additions and 5 deletions
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20
drivers/md/dm-snap-persistent.c
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@ -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;