linux/drivers/md
Linggang Zeng 667c3f5237 bcache: fix NULL pointer in cache_set_flush()
[ Upstream commit 1e46ed947e ]

1. LINE#1794 - LINE#1887 is some codes about function of
   bch_cache_set_alloc().
2. LINE#2078 - LINE#2142 is some codes about function of
   register_cache_set().
3. register_cache_set() will call bch_cache_set_alloc() in LINE#2098.

 1794 struct cache_set *bch_cache_set_alloc(struct cache_sb *sb)
 1795 {
 ...
 1860         if (!(c->devices = kcalloc(c->nr_uuids, sizeof(void *), GFP_KERNEL)) ||
 1861             mempool_init_slab_pool(&c->search, 32, bch_search_cache) ||
 1862             mempool_init_kmalloc_pool(&c->bio_meta, 2,
 1863                                 sizeof(struct bbio) + sizeof(struct bio_vec) *
 1864                                 bucket_pages(c)) ||
 1865             mempool_init_kmalloc_pool(&c->fill_iter, 1, iter_size) ||
 1866             bioset_init(&c->bio_split, 4, offsetof(struct bbio, bio),
 1867                         BIOSET_NEED_BVECS|BIOSET_NEED_RESCUER) ||
 1868             !(c->uuids = alloc_bucket_pages(GFP_KERNEL, c)) ||
 1869             !(c->moving_gc_wq = alloc_workqueue("bcache_gc",
 1870                                                 WQ_MEM_RECLAIM, 0)) ||
 1871             bch_journal_alloc(c) ||
 1872             bch_btree_cache_alloc(c) ||
 1873             bch_open_buckets_alloc(c) ||
 1874             bch_bset_sort_state_init(&c->sort, ilog2(c->btree_pages)))
 1875                 goto err;
                      ^^^^^^^^
 1876
 ...
 1883         return c;
 1884 err:
 1885         bch_cache_set_unregister(c);
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 1886         return NULL;
 1887 }
 ...
 2078 static const char *register_cache_set(struct cache *ca)
 2079 {
 ...
 2098         c = bch_cache_set_alloc(&ca->sb);
 2099         if (!c)
 2100                 return err;
                      ^^^^^^^^^^
 ...
 2128         ca->set = c;
 2129         ca->set->cache[ca->sb.nr_this_dev] = ca;
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 ...
 2138         return NULL;
 2139 err:
 2140         bch_cache_set_unregister(c);
 2141         return err;
 2142 }

(1) If LINE#1860 - LINE#1874 is true, then do 'goto err'(LINE#1875) and
    call bch_cache_set_unregister()(LINE#1885).
(2) As (1) return NULL(LINE#1886), LINE#2098 - LINE#2100 would return.
(3) As (2) has returned, LINE#2128 - LINE#2129 would do *not* give the
    value to c->cache[], it means that c->cache[] is NULL.

LINE#1624 - LINE#1665 is some codes about function of cache_set_flush().
As (1), in LINE#1885 call
bch_cache_set_unregister()
---> bch_cache_set_stop()
     ---> closure_queue()
          -.-> cache_set_flush() (as below LINE#1624)

 1624 static void cache_set_flush(struct closure *cl)
 1625 {
 ...
 1654         for_each_cache(ca, c, i)
 1655                 if (ca->alloc_thread)
                          ^^
 1656                         kthread_stop(ca->alloc_thread);
 ...
 1665 }

(4) In LINE#1655 ca is NULL(see (3)) in cache_set_flush() then the
    kernel crash occurred as below:
[  846.712887] bcache: register_cache() error drbd6: cannot allocate memory
[  846.713242] bcache: register_bcache() error : failed to register device
[  846.713336] bcache: cache_set_free() Cache set 2f84bdc1-498a-4f2f-98a7-01946bf54287 unregistered
[  846.713768] BUG: unable to handle kernel NULL pointer dereference at 00000000000009f8
[  846.714790] PGD 0 P4D 0
[  846.715129] Oops: 0000 [#1] SMP PTI
[  846.715472] CPU: 19 PID: 5057 Comm: kworker/19:16 Kdump: loaded Tainted: G           OE    --------- -  - 4.18.0-147.5.1.el8_1.5es.3.x86_64 #1
[  846.716082] Hardware name: ESPAN GI-25212/X11DPL-i, BIOS 2.1 06/15/2018
[  846.716451] Workqueue: events cache_set_flush [bcache]
[  846.716808] RIP: 0010:cache_set_flush+0xc9/0x1b0 [bcache]
[  846.717155] Code: 00 4c 89 a5 b0 03 00 00 48 8b 85 68 f6 ff ff a8 08 0f 84 88 00 00 00 31 db 66 83 bd 3c f7 ff ff 00 48 8b 85 48 ff ff ff 74 28 <48> 8b b8 f8 09 00 00 48 85 ff 74 05 e8 b6 58 a2 e1 0f b7 95 3c f7
[  846.718026] RSP: 0018:ffffb56dcf85fe70 EFLAGS: 00010202
[  846.718372] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[  846.718725] RDX: 0000000000000001 RSI: 0000000040000001 RDI: 0000000000000000
[  846.719076] RBP: ffffa0ccc0f20df8 R08: ffffa0ce1fedb118 R09: 000073746e657665
[  846.719428] R10: 8080808080808080 R11: 0000000000000000 R12: ffffa0ce1fee8700
[  846.719779] R13: ffffa0ccc0f211a8 R14: ffffa0cd1b902840 R15: ffffa0ccc0f20e00
[  846.720132] FS:  0000000000000000(0000) GS:ffffa0ce1fec0000(0000) knlGS:0000000000000000
[  846.720726] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  846.721073] CR2: 00000000000009f8 CR3: 00000008ba00a005 CR4: 00000000007606e0
[  846.721426] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  846.721778] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  846.722131] PKRU: 55555554
[  846.722467] Call Trace:
[  846.722814]  process_one_work+0x1a7/0x3b0
[  846.723157]  worker_thread+0x30/0x390
[  846.723501]  ? create_worker+0x1a0/0x1a0
[  846.723844]  kthread+0x112/0x130
[  846.724184]  ? kthread_flush_work_fn+0x10/0x10
[  846.724535]  ret_from_fork+0x35/0x40

Now, check whether that ca is NULL in LINE#1655 to fix the issue.

Signed-off-by: Linggang Zeng <linggang.zeng@easystack.cn>
Signed-off-by: Mingzhe Zou <mingzhe.zou@easystack.cn>
Signed-off-by: Coly Li <colyli@kernel.org>
Link: https://lore.kernel.org/r/20250527051601.74407-2-colyli@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2025-07-06 11:01:34 +02:00
..
bcache bcache: fix NULL pointer in cache_set_flush() 2025-07-06 11:01:34 +02:00
dm-vdo dm vdo indexer: don't read request structure after enqueuing 2025-07-06 11:01:32 +02:00
persistent-data dm array: fix cursor index when skipping across block boundaries 2025-01-17 13:40:34 +01:00
dm-audit.c dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-audit.h dm: introduce audit event module for device mapper 2021-10-27 16:53:47 -04:00
dm-bio-prison-v1.c dm: update relevant MODULE_AUTHOR entries to latest dm-devel mailing list 2024-02-20 14:22:55 -05:00
dm-bio-prison-v1.h dm bio prison v1: add dm_cell_key_has_valid_range 2023-03-30 15:57:51 -04:00
dm-bio-prison-v2.c dm: use bio_list_merge_init 2024-04-01 11:53:37 -06:00
dm-bio-prison-v2.h dm: change "unsigned" to "unsigned int" 2023-02-14 14:23:06 -05:00
dm-bio-record.h dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-bufio.c dm-bufio: don't schedule in atomic context 2025-05-09 09:50:33 +02:00
dm-builtin.c dm: adjust EXPORT_SYMBOL() to follow functions immediately 2023-02-14 14:23:07 -05:00
dm-cache-background-tracker.c dm-cache: fix warnings about duplicate slab caches 2024-11-11 17:04:39 +01:00
dm-cache-background-tracker.h dm-cache: fix warnings about duplicate slab caches 2024-11-11 17:04:39 +01:00
dm-cache-block-types.h dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-cache-metadata.c dm: Constify struct dm_block_validator 2024-07-19 12:08:15 +02:00
dm-cache-metadata.h dm: change "unsigned" to "unsigned int" 2023-02-14 14:23:06 -05:00
dm-cache-policy-internal.h dm: add missing empty lines 2023-02-14 14:23:06 -05:00
dm-cache-policy-smq.c dm: update relevant MODULE_AUTHOR entries to latest dm-devel mailing list 2024-02-20 14:22:55 -05:00
dm-cache-policy.c dm: change "unsigned" to "unsigned int" 2023-02-14 14:23:06 -05:00
dm-cache-policy.h dm: address indent/space issues 2023-02-14 14:23:06 -05:00
dm-cache-target.c dm cache: prevent BUG_ON by blocking retries on failed device resumes 2025-05-29 11:02:28 +02:00
dm-clone-metadata.c dm: Make use of __assign_bit() API 2024-09-02 16:53:53 +02:00
dm-clone-metadata.h dm clone metadata: Fix return type of dm_clone_nr_of_hydrated_regions() 2020-03-27 14:42:51 -04:00
dm-clone-target.c dm: stop using blk_limits_io_{min,opt} 2024-07-10 13:10:06 +02:00
dm-core.h dm: fix dm_blk_report_zones 2025-06-19 15:32:05 +02:00
dm-crypt.c dm-crypt: track tag_offset in convert_context 2025-02-17 10:05:19 +01:00
dm-delay.c dm-delay: remove timer_lock 2024-05-09 09:10:58 -04:00
dm-dust.c dm: update relevant MODULE_AUTHOR entries to latest dm-devel mailing list 2024-02-20 14:22:55 -05:00
dm-ebs-target.c dm-ebs: fix prefetch-vs-suspend race 2025-04-20 10:15:53 +02:00
dm-era-target.c dm: Constify struct dm_block_validator 2024-07-19 12:08:15 +02:00
dm-exception-store.c dm: change "unsigned" to "unsigned int" 2023-02-14 14:23:06 -05:00
dm-exception-store.h dm: avoid spaces before function arguments or in favour of tabs 2023-02-14 14:23:06 -05:00
dm-flakey.c dm-flakey: make corrupting read bios work 2025-06-19 15:32:05 +02:00
dm-ima.c dm: avoid inline filenames 2023-02-14 14:23:07 -05:00
dm-ima.h dm: avoid inline filenames 2023-02-14 14:23:07 -05:00
dm-init.c dm init: Handle minors larger than 255 2024-07-02 20:53:41 +02:00
dm-integrity.c dm-integrity: fix a warning on invalid table line 2025-05-09 09:50:33 +02:00
dm-io-rewind.c dm: avoid void function return statements 2023-02-14 14:23:07 -05:00
dm-io-tracker.h dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-io.c dm io: remove code duplication between sync_io and aysnc_io 2024-07-02 12:00:43 +02:00
dm-ioctl.c dm resume: don't return EINVAL when signalled 2024-08-13 13:51:34 +02:00
dm-kcopyd.c dm io: Support IO priority 2024-02-20 14:22:51 -05:00
dm-linear.c dm: optimize flushes 2024-06-26 11:32:39 -04:00
dm-log-userspace-base.c dm: update relevant MODULE_AUTHOR entries to latest dm-devel mailing list 2024-02-20 14:22:55 -05:00
dm-log-userspace-transfer.c dm: avoid split of quoted strings where possible 2023-02-14 14:23:07 -05:00
dm-log-userspace-transfer.h dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-log-writes.c dm: always manage discard support in terms of max_hw_discard_sectors 2024-05-20 15:51:19 -04:00
dm-log.c dm: update relevant MODULE_AUTHOR entries to latest dm-devel mailing list 2024-02-20 14:22:55 -05:00
dm-mpath.c dm mpath: don't call dm_get_device in multipath_message 2024-07-10 13:10:06 +02:00
dm-mpath.h dm: change "unsigned" to "unsigned int" 2023-02-14 14:23:06 -05:00
dm-path-selector.c dm: adjust EXPORT_SYMBOL() to follow functions immediately 2023-02-14 14:23:07 -05:00
dm-path-selector.h dm: avoid spaces before function arguments or in favour of tabs 2023-02-14 14:23:06 -05:00
dm-ps-historical-service-time.c dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-ps-io-affinity.c dm: address space issues relative to switch/while/for/... 2023-02-14 14:23:06 -05:00
dm-ps-queue-length.c dm: avoid spaces before function arguments or in favour of tabs 2023-02-14 14:23:06 -05:00
dm-ps-round-robin.c dm: update relevant MODULE_AUTHOR entries to latest dm-devel mailing list 2024-02-20 14:22:55 -05:00
dm-ps-service-time.c dm: avoid spaces before function arguments or in favour of tabs 2023-02-14 14:23:06 -05:00
dm-raid.c - Misc VDO fixes 2024-09-27 09:12:51 -07:00
dm-raid1.c dm-mirror: fix a tiny race condition 2025-06-27 11:11:23 +01:00
dm-region-hash.c dm: update relevant MODULE_AUTHOR entries to latest dm-devel mailing list 2024-02-20 14:22:55 -05:00
dm-rq.c Revert "dm: requeue IO if mapping table not yet available" 2024-09-15 21:02:54 +02:00
dm-rq.h dm: change "unsigned" to "unsigned int" 2023-02-14 14:23:06 -05:00
dm-snap-persistent.c dm io: Support IO priority 2024-02-20 14:22:51 -05:00
dm-snap-transient.c dm: avoid split of quoted strings where possible 2023-02-14 14:23:07 -05:00
dm-snap.c dm: always manage discard support in terms of max_hw_discard_sectors 2024-05-20 15:51:19 -04:00
dm-stats.c dm stats: limit the number of entries 2024-01-30 14:06:44 -05:00
dm-stats.h dm stats: check for and propagate alloc_percpu failure 2023-03-16 13:37:06 -04:00
dm-stripe.c dm: stop using blk_limits_io_{min,opt} 2024-07-10 13:10:06 +02:00
dm-switch.c dm: add helper macro for simple DM target module init and exit 2023-04-11 12:09:08 -04:00
dm-sysfs.c dm sysfs: make kobj_type structure constant 2023-02-14 14:23:08 -05:00
dm-table.c dm: lock limits when reading them 2025-06-27 11:11:23 +01:00
dm-target.c dm: always manage discard support in terms of max_hw_discard_sectors 2024-05-20 15:51:19 -04:00
dm-thin-metadata.c dm: Constify struct dm_block_validator 2024-07-19 12:08:15 +02:00
dm-thin-metadata.h dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-thin.c dm thin: make get_first_thin use rcu-safe list first function 2025-01-17 13:40:45 +01:00
dm-uevent.c dm: avoid spaces before function arguments or in favour of tabs 2023-02-14 14:23:06 -05:00
dm-uevent.h dm: fix undue/missing spaces 2023-02-14 14:23:06 -05:00
dm-unstripe.c dm-unstriped: cast an operand to sector_t to prevent potential uint32_t overflow 2024-11-04 17:34:56 +01:00
dm-verity-fec.c dm-verity: fix a memory leak if some arguments are specified multiple times 2025-06-27 11:11:23 +01:00
dm-verity-fec.h dm-verity: always "map" the data blocks 2024-07-03 21:41:11 +02:00
dm-verity-loadpin.c dm: verity-loadpin: Add NULL pointer check for 'bdev' parameter 2023-06-28 10:43:04 -07:00
dm-verity-target.c dm-verity: fix a memory leak if some arguments are specified multiple times 2025-06-27 11:11:23 +01:00
dm-verity-verify-sig.c dm-verity: fix a memory leak if some arguments are specified multiple times 2025-06-27 11:11:23 +01:00
dm-verity-verify-sig.h dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-verity.h dm-verity: don't crash if panic_on_corruption is not selected 2024-11-04 17:39:23 +01:00
dm-writecache.c dm: update relevant MODULE_AUTHOR entries to latest dm-devel mailing list 2024-02-20 14:22:55 -05:00
dm-zero.c dm: always manage discard support in terms of max_hw_discard_sectors 2024-05-20 15:51:19 -04:00
dm-zone.c dm: fix dm_blk_report_zones 2025-06-19 15:32:05 +02:00
dm-zoned-metadata.c block: remove gfp_flags from blkdev_zone_mgmt 2024-02-12 08:41:16 -07:00
dm-zoned-reclaim.c dm: Fix dm-zoned-reclaim zone write pointer alignment 2024-12-19 18:13:00 +01:00
dm-zoned-target.c dm: stop using blk_limits_io_{min,opt} 2024-07-10 13:10:06 +02:00
dm-zoned.h dm/dm-zoned: Use the enum req_op type 2022-07-14 12:14:31 -06:00
dm.c dm: free table mempools if not used in __bind 2025-06-19 15:32:04 +02:00
dm.h dm: Remove unused declaration and empty definition "dm_zone_map_bio" 2024-08-21 13:12:12 +02:00
Kconfig md: reintroduce md-linear 2025-02-17 10:05:04 +01:00
Makefile md: reintroduce md-linear 2025-02-17 10:05:04 +01:00
md-autodetect.c md: reintroduce md-linear 2025-02-17 10:05:04 +01:00
md-bitmap.c md/md-bitmap: fix dm-raid max_write_behind setting 2025-07-06 11:01:34 +02:00
md-bitmap.h md/md-bitmap: remove the last parameter for bimtap_ops->endwrite() 2025-02-08 09:58:11 +01:00
md-cluster.c md/md-bitmap: make in memory structure internal 2024-08-27 12:43:16 -07:00
md-cluster.h md-cluster: fix no recovery job when adding/re-adding a disk 2024-07-12 01:30:18 +00:00
md-linear.c md: Fix linear_set_limits() 2025-02-17 10:05:47 +01:00
md.c md: fix mddev uaf while iterating all_mddevs list 2025-04-25 10:48:04 +02:00
md.h md/md-bitmap: move bitmap_{start, end}write to md upper layer 2025-02-08 09:58:12 +01:00
raid0.c md/raid*: Fix the set_queue_limits implementations 2025-02-27 04:30:19 -08:00
raid0.h md/raid0: add discard support for the 'original' layout 2023-06-30 15:43:50 -07:00
raid1-10.c md/md-bitmap: merge md_bitmap_enabled() into bitmap_operations 2024-08-27 12:43:16 -07:00
raid1.c md/raid1: Add check for missing source disk in process_checks() 2025-05-02 07:59:28 +02:00
raid1.h md/md-bitmap: remove the last parameter for bimtap_ops->endwrite() 2025-02-08 09:58:11 +01:00
raid5-cache.c md/md-bitmap: move bitmap_{start, end}write to md upper layer 2025-02-08 09:58:12 +01:00
raid5-log.h md/raid5-ppl: Drop unused argument from ppl_handle_flush_request() 2022-08-02 17:14:31 -06:00
raid5-ppl.c md: remove mddev->queue 2024-03-06 08:59:53 -08:00
raid5.c md/md-bitmap: move bitmap_{start, end}write to md upper layer 2025-02-08 09:58:12 +01:00
raid5.h md/md-bitmap: move bitmap_{start, end}write to md upper layer 2025-02-08 09:58:12 +01:00
raid10.c md/raid10: fix missing discard IO accounting 2025-04-25 10:47:38 +02:00
raid10.h md/md-bitmap: remove the last parameter for bimtap_ops->endwrite() 2025-02-08 09:58:11 +01:00