Eric Biggers d124b2c53c FS-Cache: fix dereference of NULL user_key_payload ...

When the file /proc/fs/fscache/objects (available with
CONFIG_FSCACHE_OBJECT_LIST=y) is opened, we request a user key with
description "fscache:objlist", then access its payload.  However, a
revoked key has a NULL payload, and we failed to check for this.
request_key() *does* skip revoked keys, but there is still a window
where the key can be revoked before we access its payload.

Fix it by checking for a NULL payload, treating it like a key which was
already revoked at the time it was requested.

Fixes: 4fbf4291aa15 ("FS-Cache: Allow the current state of all objects to be dumped")
Reviewed-by: James Morris <james.l.morris@oracle.com>
Cc: <stable@vger.kernel.org>    [v2.6.32+]
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>

2017-10-12 17:16:40 +01:00

..

cache.c

fs/fscache: convert printk to pr_foo()

2014-06-04 16:53:51 -07:00

cookie.c

fscache: Clear outstanding writes when disabling a cookie

2017-01-31 13:23:09 -05:00

fsdef.c

FS-Cache: Provide the ability to enable/disable cookies

2013-09-27 18:40:25 +01:00

histogram.c

drop redundant ->owner initializations

2016-05-29 19:08:00 -04:00

internal.h

FS-Cache: The operation cancellation method needs calling in more places

2015-04-02 14:28:53 +01:00

Kconfig

fscache: drop references to slow-work

2010-07-22 22:58:58 +02:00

main.c

fs/fscache: make ctl_table static

2014-08-06 18:01:12 -07:00

Makefile

FS-Cache: Allow the current state of all objects to be dumped

2009-11-19 18:11:04 +00:00

netfs.c

FS-Cache: Initialise stores_lock in netfs cookie

2017-01-31 13:23:09 -05:00

object-list.c

FS-Cache: fix dereference of NULL user_key_payload

2017-10-12 17:16:40 +01:00

object.c

fscache: Fix dead object requeue

2017-01-31 13:23:09 -05:00

operation.c

FS-Cache: Retain the netfs context in the retrieval op earlier

2015-04-02 14:28:53 +01:00

page.c

mm: remove nr_pages argument from pagevec_lookup{,_range}()

2017-09-06 17:27:27 -07:00

proc.c

FS-Cache: Allow the current state of all objects to be dumped

2009-11-19 18:11:04 +00:00

stats.c

drop redundant ->owner initializations

2016-05-29 19:08:00 -04:00