linux-stable/block
Li Jinlin f58d305887 blk-cgroup: fix UAF by grabbing blkcg lock before destroying blkg pd
[ Upstream commit 858560b276 ]

KASAN reports a use-after-free report when doing fuzz test:

[693354.104835] ==================================================================
[693354.105094] BUG: KASAN: use-after-free in bfq_io_set_weight_legacy+0xd3/0x160
[693354.105336] Read of size 4 at addr ffff888be0a35664 by task sh/1453338

[693354.105607] CPU: 41 PID: 1453338 Comm: sh Kdump: loaded Not tainted 4.18.0-147
[693354.105610] Hardware name: Huawei 2288H V5/BC11SPSCB0, BIOS 0.81 07/02/2018
[693354.105612] Call Trace:
[693354.105621]  dump_stack+0xf1/0x19b
[693354.105626]  ? show_regs_print_info+0x5/0x5
[693354.105634]  ? printk+0x9c/0xc3
[693354.105638]  ? cpumask_weight+0x1f/0x1f
[693354.105648]  print_address_description+0x70/0x360
[693354.105654]  kasan_report+0x1b2/0x330
[693354.105659]  ? bfq_io_set_weight_legacy+0xd3/0x160
[693354.105665]  ? bfq_io_set_weight_legacy+0xd3/0x160
[693354.105670]  bfq_io_set_weight_legacy+0xd3/0x160
[693354.105675]  ? bfq_cpd_init+0x20/0x20
[693354.105683]  cgroup_file_write+0x3aa/0x510
[693354.105693]  ? ___slab_alloc+0x507/0x540
[693354.105698]  ? cgroup_file_poll+0x60/0x60
[693354.105702]  ? 0xffffffff89600000
[693354.105708]  ? usercopy_abort+0x90/0x90
[693354.105716]  ? mutex_lock+0xef/0x180
[693354.105726]  kernfs_fop_write+0x1ab/0x280
[693354.105732]  ? cgroup_file_poll+0x60/0x60
[693354.105738]  vfs_write+0xe7/0x230
[693354.105744]  ksys_write+0xb0/0x140
[693354.105749]  ? __ia32_sys_read+0x50/0x50
[693354.105760]  do_syscall_64+0x112/0x370
[693354.105766]  ? syscall_return_slowpath+0x260/0x260
[693354.105772]  ? do_page_fault+0x9b/0x270
[693354.105779]  ? prepare_exit_to_usermode+0xf9/0x1a0
[693354.105784]  ? enter_from_user_mode+0x30/0x30
[693354.105793]  entry_SYSCALL_64_after_hwframe+0x65/0xca

[693354.105875] Allocated by task 1453337:
[693354.106001]  kasan_kmalloc+0xa0/0xd0
[693354.106006]  kmem_cache_alloc_node_trace+0x108/0x220
[693354.106010]  bfq_pd_alloc+0x96/0x120
[693354.106015]  blkcg_activate_policy+0x1b7/0x2b0
[693354.106020]  bfq_create_group_hierarchy+0x1e/0x80
[693354.106026]  bfq_init_queue+0x678/0x8c0
[693354.106031]  blk_mq_init_sched+0x1f8/0x460
[693354.106037]  elevator_switch_mq+0xe1/0x240
[693354.106041]  elevator_switch+0x25/0x40
[693354.106045]  elv_iosched_store+0x1a1/0x230
[693354.106049]  queue_attr_store+0x78/0xb0
[693354.106053]  kernfs_fop_write+0x1ab/0x280
[693354.106056]  vfs_write+0xe7/0x230
[693354.106060]  ksys_write+0xb0/0x140
[693354.106064]  do_syscall_64+0x112/0x370
[693354.106069]  entry_SYSCALL_64_after_hwframe+0x65/0xca

[693354.106114] Freed by task 1453336:
[693354.106225]  __kasan_slab_free+0x130/0x180
[693354.106229]  kfree+0x90/0x1b0
[693354.106233]  blkcg_deactivate_policy+0x12c/0x220
[693354.106238]  bfq_exit_queue+0xf5/0x110
[693354.106241]  blk_mq_exit_sched+0x104/0x130
[693354.106245]  __elevator_exit+0x45/0x60
[693354.106249]  elevator_switch_mq+0xd6/0x240
[693354.106253]  elevator_switch+0x25/0x40
[693354.106257]  elv_iosched_store+0x1a1/0x230
[693354.106261]  queue_attr_store+0x78/0xb0
[693354.106264]  kernfs_fop_write+0x1ab/0x280
[693354.106268]  vfs_write+0xe7/0x230
[693354.106271]  ksys_write+0xb0/0x140
[693354.106275]  do_syscall_64+0x112/0x370
[693354.106280]  entry_SYSCALL_64_after_hwframe+0x65/0xca

[693354.106329] The buggy address belongs to the object at ffff888be0a35580
                 which belongs to the cache kmalloc-1k of size 1024
[693354.106736] The buggy address is located 228 bytes inside of
                 1024-byte region [ffff888be0a35580, ffff888be0a35980)
[693354.107114] The buggy address belongs to the page:
[693354.107273] page:ffffea002f828c00 count:1 mapcount:0 mapping:ffff888107c17080 index:0x0 compound_mapcount: 0
[693354.107606] flags: 0x17ffffc0008100(slab|head)
[693354.107760] raw: 0017ffffc0008100 ffffea002fcbc808 ffffea0030bd3a08 ffff888107c17080
[693354.108020] raw: 0000000000000000 00000000001c001c 00000001ffffffff 0000000000000000
[693354.108278] page dumped because: kasan: bad access detected

[693354.108511] Memory state around the buggy address:
[693354.108671]  ffff888be0a35500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[693354.116396]  ffff888be0a35580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[693354.124473] >ffff888be0a35600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[693354.132421]                                                        ^
[693354.140284]  ffff888be0a35680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[693354.147912]  ffff888be0a35700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[693354.155281] ==================================================================

blkgs are protected by both queue and blkcg locks and holding
either should stabilize them. However, the path of destroying
blkg policy data is only protected by queue lock in
blkcg_activate_policy()/blkcg_deactivate_policy(). Other tasks
can get the blkg policy data before the blkg policy data is
destroyed, and use it after destroyed, which will result in a
use-after-free.

CPU0                             CPU1
blkcg_deactivate_policy
  spin_lock_irq(&q->queue_lock)
                                 bfq_io_set_weight_legacy
                                   spin_lock_irq(&blkcg->lock)
                                   blkg_to_bfqg(blkg)
                                     pd_to_bfqg(blkg->pd[pol->plid])
                                     ^^^^^^blkg->pd[pol->plid] != NULL
                                           bfqg != NULL
  pol->pd_free_fn(blkg->pd[pol->plid])
    pd_to_bfqg(blkg->pd[pol->plid])
    bfqg_put(bfqg)
      kfree(bfqg)
  blkg->pd[pol->plid] = NULL
  spin_unlock_irq(q->queue_lock);
                                   bfq_group_set_weight(bfqg, val, 0)
                                     bfqg->entity.new_weight
                                     ^^^^^^trigger uaf here
                                   spin_unlock_irq(&blkcg->lock);

Fix by grabbing the matching blkcg lock before trying to
destroy blkg policy data.

Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Li Jinlin <lijinlin3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20210914042605.3260596-1-lijinlin3@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-30 10:11:07 +02:00
..
partitions partitions: msdos: fix one-byte get_unaligned() 2021-07-20 16:05:39 +02:00
badblocks.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
bfq-cgroup.c bfq: fix blkio cgroup leakage v4 2020-08-18 07:48:08 -07:00
bfq-iosched.c block, bfq: honor already-setup queue merges 2021-09-22 12:28:01 +02:00
bfq-iosched.h bfq: fix blkio cgroup leakage v4 2020-08-18 07:48:08 -07:00
bfq-wf2q.c bfq: fix blkio cgroup leakage v4 2020-08-18 07:48:08 -07:00
bio-integrity.c block: make function __bio_integrity_free() static 2020-07-02 12:38:18 -06:00
bio.c bio: fix page leak bio_add_hw_page failure 2021-09-15 09:50:47 +02:00
blk-cgroup-rwstat.c blk-cgroup: Fix the recursive blkg rwstat 2021-03-30 14:31:48 +02:00
blk-cgroup-rwstat.h blk-cgroup: separate out blkg_rwstat under CONFIG_BLK_CGROUP_RWSTAT 2019-11-07 12:28:13 -07:00
blk-cgroup.c blk-cgroup: fix UAF by grabbing blkcg lock before destroying blkg pd 2021-09-30 10:11:07 +02:00
blk-core.c blk-mq: fix kernel panic during iterating over flush request 2021-09-12 08:58:27 +02:00
blk-crypto-fallback.c block: rename generic_make_request to submit_bio_noacct 2020-07-01 07:27:24 -06:00
blk-crypto-internal.h block: make blk_crypto_rq_bio_prep() able to fail 2020-10-05 10:47:43 -06:00
blk-crypto.c blk-crypto: fix check for too-large dun_bytes 2021-09-15 09:50:30 +02:00
blk-exec.c block: add a blk_account_io_merge_bio helper 2020-05-27 05:21:23 -06:00
blk-flush.c blk-mq: fix is_flush_rq 2021-09-12 08:58:27 +02:00
blk-integrity.c block: flush the integrity workqueue in blk_integrity_unregister 2021-09-30 10:11:06 +02:00
blk-ioc.c block: remove retry loop in ioc_release_fn() 2020-07-16 10:22:15 -06:00
blk-iocost.c blk-iocost: fix lockdep warning on blkcg->lock 2021-09-03 10:09:22 +02:00
blk-iolatency.c blk-iolatency: error out if blk_get_queue() failed in iolatency_set_limit() 2021-08-12 13:22:08 +02:00
blk-lib.c block: add a bdev_is_partition helper 2020-09-25 08:18:57 -06:00
blk-map.c block: fix bmd->is_null_mapped initialization 2020-09-23 09:18:39 -06:00
blk-merge.c block: return ELEVATOR_DISCARD_MERGE if possible 2021-09-15 09:50:28 +02:00
blk-mq-cpumap.c blk-mq: remove the calling of local_memory_node() 2020-10-20 07:08:17 -06:00
blk-mq-debugfs-zoned.c block: Cleanup license notice 2019-01-17 21:21:40 -07:00
blk-mq-debugfs.c blk-mq-debugfs: Add decode for BLK_MQ_F_TAG_HCTX_SHARED 2021-01-19 18:27:29 +01:00
blk-mq-debugfs.h blk-mq: no need to check return value of debugfs_create functions 2019-06-13 03:00:30 -06:00
blk-mq-pci.c block: Fix blk_mq_*_map_queues() kernel-doc headers 2019-05-31 15:12:34 -06:00
blk-mq-rdma.c block: Fix blk_mq_*_map_queues() kernel-doc headers 2019-05-31 15:12:34 -06:00
blk-mq-sched.c treewide: Change list_sort to use const pointers 2021-09-30 10:11:04 +02:00
blk-mq-sched.h block-5.10-2020-10-12 2020-10-13 12:12:44 -07:00
blk-mq-sysfs.c blk-mq: move cancel of hctx->run_work to the front of blk_exit_queue 2020-10-09 12:46:28 -06:00
blk-mq-tag.c blk-mq: avoid to iterate over stale request 2021-09-30 10:11:05 +02:00
blk-mq-tag.h blk-mq: clear stale request in tags->rq[] before freeing one request pool 2021-07-14 16:55:58 +02:00
blk-mq-virtio.c blk-mq: Fix typo in comment 2020-03-17 20:55:21 +01:00
blk-mq.c treewide: Change list_sort to use const pointers 2021-09-30 10:11:04 +02:00
blk-mq.h blk-mq: grab rq->refcount before calling ->fn in blk_mq_tagset_busy_iter 2021-07-14 16:55:58 +02:00
blk-pm.c scsi: block: Fix a race in the runtime power management code 2021-01-06 14:56:50 +01:00
blk-pm.h scsi: block: Do not accept any requests while suspended 2021-01-12 20:18:17 +01:00
blk-rq-qos.c rq-qos: fix missed wake-ups in rq_qos_throttle try two 2021-07-19 09:45:00 +02:00
blk-rq-qos.h block: fix race between adding/removing rq qos and normal IO 2021-07-14 16:56:00 +02:00
blk-settings.c blk-settings: align max_sectors on "logical_block_size" boundary 2021-03-04 11:38:22 +01:00
blk-stat.c blk-stat: make q->stats->lock irqsafe 2020-09-01 16:48:46 -06:00
blk-stat.h
blk-sysfs.c blk-mq: move cancel of hctx->run_work to the front of blk_exit_queue 2020-10-09 12:46:28 -06:00
blk-throttle.c blk-throttle: fix UAF by deleteing timer in blk_throtl_exit() 2021-09-26 14:09:01 +02:00
blk-timeout.c block: blk-timeout: delete duplicated word 2020-07-31 16:29:47 -06:00
blk-wbt.c blk-wbt: make sure throttle is enabled properly 2021-07-14 16:56:12 +02:00
blk-wbt.h blk-wbt: introduce a new disable state to prevent false positive by rwb_enabled() 2021-07-14 16:56:12 +02:00
blk-zoned.c blk-zoned: allow BLKREPORTZONE without CAP_SYS_ADMIN 2021-09-18 13:40:06 +02:00
blk.h blk-throtl: optimize IOPS throttle for large IO scenarios 2021-09-15 09:50:25 +02:00
bounce.c block: make bio_crypt_clone() able to fail 2020-10-05 10:47:43 -06:00
bsg-lib.c block: drop double zeroing 2020-09-23 09:18:13 -06:00
bsg.c scsi: bsg: Remove support for SCSI_IOCTL_SEND_COMMAND 2021-09-18 13:40:11 +02:00
cmdline-parser.c
elevator.c block: return ELEVATOR_DISCARD_MERGE if possible 2021-09-15 09:50:28 +02:00
genhd.c block: Suppress uevent for hidden device when removed 2021-03-30 14:31:52 +02:00
ioctl.c block: return -EBUSY when there are open partitions in blkdev_reread_part 2021-04-28 13:39:59 +02:00
ioprio.c block: grant IOPRIO_CLASS_RT to CAP_SYS_NICE 2020-09-01 19:38:33 -06:00
Kconfig blk-wbt: Remove obsolete multiqueue I/O scheduling comment 2020-09-01 16:49:26 -06:00
Kconfig.iosched treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
keyslot-manager.c block/keyslot-manager: prevent crash when num_slots=1 2020-11-20 11:52:52 -07:00
kyber-iosched.c kyber: fix out of bounds access when preempted 2021-05-19 10:13:13 +02:00
Makefile blk-mq: merge blk-softirq.c into blk-mq.c 2020-06-24 09:15:56 -06:00
mq-deadline.c block: return ELEVATOR_DISCARD_MERGE if possible 2021-09-15 09:50:28 +02:00
opal_proto.h block: sed-opal: Change the check condition for regular session validity 2020-03-12 08:00:10 -06:00
scsi_ioctl.c drivers-5.10-2020-10-12 2020-10-13 13:04:41 -07:00
sed-opal.c block: sed-opal: Change the check condition for regular session validity 2020-03-12 08:00:10 -06:00
t10-pi.c block: Allow t10-pi to be modular 2020-01-06 20:59:04 -07:00