Milan Broz f4808ca99a dm table: reject devices without request fns ... This patch adds a check that a block device has a request function defined before it is used. Otherwise, misconfiguration can cause an oops. Because we are allowing devices with zero size e.g. an offline multipath device as in commit 2cd54d9bed ("dm: allow offline devices") there needs to be an additional check to ensure devices are initialised. Some block devices, like a loop device without a backing file, exist but have no request function. Reproducer is trivial: dm-mirror on unbound loop device (no backing file on loop devices) dmsetup create x --table "0 8 mirror core 2 8 sync 2 /dev/loop0 0 /dev/loop1 0" and mirror resync will immediatelly cause OOps. BUG: unable to handle kernel NULL pointer dereference at (null) ? generic_make_request+0x2bd/0x590 ? kmem_cache_alloc+0xad/0x190 submit_bio+0x53/0xe0 ? bio_add_page+0x3b/0x50 dispatch_io+0x1ca/0x210 [dm_mod] ? read_callback+0x0/0xd0 [dm_mirror] dm_io+0xbb/0x290 [dm_mod] do_mirror+0x1e0/0x748 [dm_mirror] Signed-off-by: Milan Broz <mbroz@redhat.com> Reported-by: Zdenek Kabelac <zkabelac@redhat.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@kernel.org Signed-off-by: Alasdair G Kergon <agk@redhat.com>		2011-05-29 13:02:52 +01:00
..
bitmap.c	md/bitmap: fix saving of events_cleared and other state.	2011-05-11 14:26:30 +10:00
bitmap.h	Fix common misspellings	2011-03-31 11:26:23 -03:00
dm-bio-record.h	dm: preserve bi_io_vec when resubmitting bios	2009-04-02 19:55:23 +01:00
dm-crypt.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm	2011-03-25 20:51:44 -07:00
dm-delay.c	dm: convert workqueues to alloc_ordered	2011-01-13 19:59:57 +00:00
dm-exception-store.c	dm snapshot: test chunk size against both origin and snapshot	2010-08-12 04:13:51 +01:00
dm-exception-store.h	dm snapshot: test chunk size against both origin and snapshot	2010-08-12 04:13:51 +01:00
dm-flakey.c	dm: add flakey target	2011-03-24 13:54:24 +00:00
dm-io.c	block: kill off REQ_UNPLUG	2011-03-10 08:52:27 +01:00
dm-ioctl.c	dm ioctl: add flag to wipe buffers for secure data	2011-03-24 13:54:30 +00:00
dm-kcopyd.c	block: kill off REQ_UNPLUG	2011-03-10 08:52:27 +01:00
dm-linear.c	dm: use dm_target_offset macro	2010-08-12 04:14:11 +01:00
dm-log-userspace-base.c	dm log userspace: add version number to comms	2011-01-13 19:59:52 +00:00
dm-log-userspace-transfer.c	netlink: kill eff_cap from struct netlink_skb_parms	2011-03-03 13:32:07 -08:00
dm-log-userspace-transfer.h	dm log: userspace add luid to distinguish between concurrent log instances	2009-09-04 20:40:34 +01:00
dm-log.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm	2011-03-25 20:51:44 -07:00
dm-mpath.c	dm mpath: allow table load with no priority groups	2011-03-24 13:54:33 +00:00
dm-mpath.h
dm-path-selector.c	dm: path selector use module refcount directly	2009-04-02 19:55:27 +01:00
dm-path-selector.h	dm mpath: add start_io and nr_bytes to path selectors	2009-06-22 10:12:27 +01:00
dm-queue-length.c	dm mpath: add queue length load balancer	2009-06-22 10:12:27 +01:00
dm-raid1.c	block: remove per-queue plugging	2011-03-10 08:52:07 +01:00
dm-raid.c	md/dm - remove remains of plug_fn callback.	2011-04-18 18:25:41 +10:00
dm-region-hash.c	Fix common misspellings	2011-03-31 11:26:23 -03:00
dm-round-robin.c	dm mpath: add start_io and nr_bytes to path selectors	2009-06-22 10:12:27 +01:00
dm-service-time.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
dm-snap-persistent.c	dm snapshot: persistent make metadata_wq multithreaded	2011-01-13 19:59:59 +00:00
dm-snap-transient.c	dm snapshot: move cow ref from exception store to snap core	2009-12-10 23:52:12 +00:00
dm-snap.c	dm: fix opening log and cow devices for read only tables	2011-03-24 13:52:14 +00:00
dm-stripe.c	dm stripe: implement merge method	2011-03-24 13:54:35 +00:00
dm-sysfs.c	Driver core: Constify struct sysfs_ops in struct kobj_type	2010-03-07 17:04:49 -08:00
dm-table.c	dm table: reject devices without request fns	2011-05-29 13:02:52 +01:00
dm-target.c	dm: error return error for discards	2010-08-12 04:14:14 +01:00
dm-uevent.c	dm table: remove dm_get from dm_table_get_md	2010-03-06 02:29:52 +00:00
dm-uevent.h
dm-zero.c	dm: zero silently drop discards	2010-08-12 04:14:12 +01:00
dm.c	block: fix non-atomic access to genhd inflight structures	2011-03-22 08:35:35 +01:00
dm.h	block: Require subsystems to explicitly allocate bio_set integrity mempool	2011-03-17 11:11:05 +01:00
faulty.c	Fix common misspellings	2011-03-31 11:26:23 -03:00
Kconfig	dm: add flakey target	2011-03-24 13:54:24 +00:00
linear.c	block: Require subsystems to explicitly allocate bio_set integrity mempool	2011-03-17 11:11:05 +01:00
linear.h	md/linear: use call_rcu to free obsolete 'conf' structures.	2009-06-18 08:49:42 +10:00
Makefile	dm: add flakey target	2011-03-24 13:54:24 +00:00
md.c	md: allow resync_start to be set while an array is active.	2011-05-11 15:52:21 +10:00
md.h	md: provide generic support for handling unplug callbacks.	2011-04-18 18:25:42 +10:00
multipath.c	md: make error_handler functions more uniform and correct.	2011-05-11 14:38:44 +10:00
multipath.h	md/multipath: discard ->working_disks in favour of ->degraded	2011-05-11 14:38:02 +10:00
raid0.c	block: Require subsystems to explicitly allocate bio_set integrity mempool	2011-03-17 11:11:05 +01:00
raid0.h	md: fix handling of array level takeover that re-arranges devices.	2010-06-24 13:33:24 +10:00
raid1.c	md: allow resync_start to be set while an array is active.	2011-05-11 15:52:21 +10:00
raid1.h	md/raid1: improve handling of pages allocated for write-behind.	2011-05-11 14:51:19 +10:00
raid5.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2011-05-23 09:12:26 -07:00
raid5.h	md - remove old plugging code.	2011-04-18 18:25:42 +10:00
raid10.c	md/raid10: reformat some loops with less indenting.	2011-05-11 14:54:41 +10:00
raid10.h	Fix common misspellings	2011-03-31 11:26:23 -03:00