linux/drivers/md
Gui-Dong Han 8ec4a68a25 md/raid5: fix atomicity violation in raid5_cache_count
[ Upstream commit dfd2bf4367 ]

In raid5_cache_count():
    if (conf->max_nr_stripes < conf->min_nr_stripes)
        return 0;
    return conf->max_nr_stripes - conf->min_nr_stripes;
The current check is ineffective, as the values could change immediately
after being checked.

In raid5_set_cache_size():
    ...
    conf->min_nr_stripes = size;
    ...
    while (size > conf->max_nr_stripes)
        conf->min_nr_stripes = conf->max_nr_stripes;
    ...

Due to intermediate value updates in raid5_set_cache_size(), concurrent
execution of raid5_cache_count() and raid5_set_cache_size() may lead to
inconsistent reads of conf->max_nr_stripes and conf->min_nr_stripes.
The current checks are ineffective as values could change immediately
after being checked, raising the risk of conf->min_nr_stripes exceeding
conf->max_nr_stripes and potentially causing an integer overflow.

This possible bug is found by an experimental static analysis tool
developed by our team. This tool analyzes the locking APIs to extract
function pairs that can be concurrently executed, and then analyzes the
instructions in the paired functions to identify possible concurrency bugs
including data races and atomicity violations. The above possible bug is
reported when our tool analyzes the source code of Linux 6.2.

To resolve this issue, it is suggested to introduce local variables
'min_stripes' and 'max_stripes' in raid5_cache_count() to ensure the
values remain stable throughout the check. Adding locks in
raid5_cache_count() fails to resolve atomicity violations, as
raid5_set_cache_size() may hold intermediate values of
conf->min_nr_stripes while unlocked. With this patch applied, our tool no
longer reports the bug, with the kernel configuration allyesconfig for
x86_64. Due to the lack of associated hardware, we cannot test the patch
in runtime testing, and just verify it according to the code logic.

Fixes: edbe83ab4c ("md/raid5: allow the stripe_cache to grow and shrink.")
Cc: stable@vger.kernel.org
Signed-off-by: Gui-Dong Han <2045gemini@gmail.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240112071017.16313-1-2045gemini@gmail.com
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2024-04-03 15:28:22 +02:00
..
bcache bcache: avoid NULL checking to c->root in run_cache_set() 2023-12-20 17:01:56 +01:00
persistent-data dm thin metadata: Fix ABBA deadlock by resetting dm_bufio_client 2023-06-16 18:24:13 -04:00
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: improve hash_locks sizing and hash function 2023-03-30 15:57:51 -04:00
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: address space issues relative to switch/while/for/... 2023-02-14 14:23:06 -05:00
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 io: Support IO priority 2024-03-26 18:20:13 -04:00
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: change "unsigned" to "unsigned int" 2023-02-14 14:23:06 -05:00
dm-cache-background-tracker.h dm: change "unsigned" to "unsigned int" 2023-02-14 14:23:06 -05:00
dm-cache-block-types.h dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-cache-metadata.c Revert "mm: shrinkers: convert shrinker_rwsem to mutex" 2023-06-19 13:19:33 -07:00
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 cache policy smq: ensure IO doesn't prevent cleaner policy progress 2023-07-25 11:55:50 -04:00
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 block: replace fmode_t with a block-specific type for block open flags 2023-06-12 08:04:05 -06:00
dm-clone-metadata.c dm clone metadata: remove unused function 2021-04-19 13:20:31 -04:00
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 block: replace fmode_t with a block-specific type for block open flags 2023-06-12 08:04:05 -06:00
dm-core.h dm: limit the number of targets and parameter size area 2024-02-23 09:25:27 +01:00
dm-crypt.c dm-verity, dm-crypt: align "struct bvec_iter" correctly 2024-03-26 18:19:12 -04:00
dm-delay.c dm-delay: fix a race between delay_presuspend and delay_bio 2023-12-03 07:33:09 +01:00
dm-dust.c dm: add helper macro for simple DM target module init and exit 2023-04-11 12:09:08 -04:00
dm-ebs-target.c dm: add helper macro for simple DM target module init and exit 2023-04-11 12:09:08 -04:00
dm-era-target.c block: replace fmode_t with a block-specific type for block open flags 2023-06-12 08:04:05 -06:00
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: introduce random_read_corrupt and random_write_corrupt options 2023-06-16 18:24:13 -04:00
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: open code dm_get_dev_t in dm_init_init 2023-06-05 10:57:40 -06:00
dm-integrity.c dm-integrity: align the outgoing bio in integrity_recheck 2024-03-26 18:20:13 -04:00
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: Support IO priority 2024-03-26 18:20:13 -04:00
dm-ioctl.c dm: limit the number of targets and parameter size area 2024-02-23 09:25:27 +01:00
dm-kcopyd.c dm io: Support IO priority 2024-03-26 18:20:13 -04:00
dm-linear.c dm: remove unnecessary (void*) conversions 2023-04-11 12:01:01 -04:00
dm-log-userspace-base.c dm: avoid void function return statements 2023-02-14 14:23:07 -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: add helper macro for simple DM target module init and exit 2023-04-11 12:09:08 -04:00
dm-log.c dm io: Support IO priority 2024-03-26 18:20:13 -04:00
dm-mpath.c dm: push error reporting down to dm_register_target() 2023-04-11 12:01:01 -04:00
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: correct block comments format. 2023-02-14 14:23:06 -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 dm raid: fix false positive for requeue needed during reshape 2024-03-26 18:19:41 -04:00
dm-raid1.c dm io: Support IO priority 2024-03-26 18:20:13 -04:00
dm-region-hash.c dm: correct block comments format. 2023-02-14 14:23:06 -05:00
dm-rq.c dm: avoid using symbolic permissions 2023-02-14 14:23:07 -05:00
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 2024-03-26 18:20:13 -04:00
dm-snap-transient.c dm: avoid split of quoted strings where possible 2023-02-14 14:23:07 -05:00
dm-snap.c block: replace fmode_t with a block-specific type for block open flags 2023-06-12 08:04:05 -06:00
dm-stats.c dm stats: check for and propagate alloc_percpu failure 2023-03-16 13:37:06 -04:00
dm-stats.h dm stats: check for and propagate alloc_percpu failure 2023-03-16 13:37:06 -04:00
dm-stripe.c dm: remove unnecessary (void*) conversions 2023-04-11 12:01:01 -04:00
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: limit the number of targets and parameter size area 2024-02-23 09:25:27 +01:00
dm-target.c dm: push error reporting down to dm_register_target() 2023-04-11 12:01:01 -04:00
dm-thin-metadata.c - Update DM crypt to allocate compound pages if possible. 2023-06-30 12:16:00 -07:00
dm-thin-metadata.h dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-thin.c - Update DM crypt to allocate compound pages if possible. 2023-06-30 12:16:00 -07:00
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: add helper macro for simple DM target module init and exit 2023-04-11 12:09:08 -04:00
dm-verity-fec.c dm-verity: align struct dm_verity_fec_io properly 2023-12-08 08:52:16 +01:00
dm-verity-fec.h dm: change "unsigned" to "unsigned int" 2023-02-14 14:23:06 -05:00
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 io: Support IO priority 2024-03-26 18:20:13 -04:00
dm-verity-verify-sig.c dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-verity-verify-sig.h dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-verity.h dm-verity, dm-crypt: align "struct bvec_iter" correctly 2024-03-26 18:19:12 -04:00
dm-writecache.c dm io: Support IO priority 2024-03-26 18:20:13 -04:00
dm-zero.c dm: add helper macro for simple DM target module init and exit 2023-04-11 12:09:08 -04:00
dm-zone.c dm zone: Use the bitmap API to allocate bitmaps 2023-06-16 18:24:13 -04:00
dm-zoned-metadata.c dm: dm-zoned: use __bio_add_page for adding single metadata page 2023-05-31 09:50:02 -06:00
dm-zoned-reclaim.c dm kcopyd: avoid useless atomic operations 2021-06-04 12:07:24 -04:00
dm-zoned-target.c dm zoned: free dmz->ddev array in dmz_put_zoned_devices 2023-09-20 13:48:06 -04:00
dm-zoned.h dm/dm-zoned: Use the enum req_op type 2022-07-14 12:14:31 -06:00
dm.c dm: call the resume method on internal suspend 2024-03-26 18:19:41 -04:00
dm.h dm: remove stale/redundant dm_internal_{suspend,resume} prototypes in dm.h 2023-06-16 18:24:14 -04:00
Kconfig dm audit: fix Kconfig so DM_AUDIT depends on BLK_DEV_DM 2024-01-20 11:51:45 +01:00
Makefile hardening updates for v5.20-rc1 2022-08-02 14:38:59 -07:00
md-autodetect.c init: improve the name_to_dev_t interface 2023-06-05 10:56:46 -06:00
md-bitmap.c md/md-bitmap: fix incorrect usage for sb_index 2024-04-03 15:28:21 +02:00
md-bitmap.h md-bitmap: don't use ->index for pages backing the bitmap file 2023-07-27 00:13:29 -07:00
md-cluster.c md: Hold mddev->reconfig_mutex when trying to get mddev->sync_thread 2023-08-15 09:40:26 -07:00
md-cluster.h md-cluster: introduce resync_info_get interface for sanity check 2018-10-18 09:36:35 -07:00
md-faulty.c md/md-faulty: enable io accounting 2023-07-27 00:13:30 -07:00
md-linear.c md/md-linear: enable io accounting 2023-07-27 00:13:30 -07:00
md-linear.h md/raid1: Replace zero-length array with flexible-array 2020-05-13 12:02:23 -07:00
md-multipath.c md/md-multipath: enable io accounting 2023-07-27 00:13:29 -07:00
md-multipath.h md: convert to bioset_init()/mempool_init() 2018-05-30 15:33:32 -06:00
md.c md: Don't clear MD_CLOSING when the raid is about to stop 2024-03-26 18:19:17 -04:00
md.h md: fix warning for holder mismatch from export_rdev() 2023-09-08 13:16:40 -07:00
raid0.c md: raid0: account for split bio in iostat accounting 2023-08-17 21:11:31 -07:00
raid0.h md/raid0: add discard support for the 'original' layout 2023-06-30 15:43:50 -07:00
raid1-10.c md/raid1-10: fix casting from randomized structure in raid1_submit_write() 2023-06-23 09:33:16 -07:00
raid1.c md/raid1: Use blk_opf_t for read and write operations 2024-01-25 15:35:46 -08:00
raid1.h md/raid1: switch to use md_account_bio() for io accounting 2023-07-27 00:13:29 -07:00
raid5-cache.c md/raid5-cache: fix null-ptr-deref for r5l_flush_stripe_to_raid() 2023-08-15 09:40:27 -07:00
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: raid5: use __bio_add_page to add single page to new bio 2023-05-31 09:50:02 -06:00
raid5.c md/raid5: fix atomicity violation in raid5_cache_count 2024-04-03 15:28:22 +02:00
raid5.h hardening updates for v6.5-rc1 2023-06-27 21:24:18 -07:00
raid10.c md: Hold mddev->reconfig_mutex when trying to get mddev->sync_thread 2023-08-15 09:40:26 -07:00
raid10.h md/raid10: switch to use md_account_bio() for io accounting 2023-07-27 00:13:29 -07:00