kernel/linux.git/block, branch v5.10.78

block: decode QUEUE_FLAG_HCTX_ACTIVE in debugfs output

2021-10-27T07:56:46+00:00

[ Upstream commit 1dbdd99b511c966be9147ad72991a2856ac76f22 ] While debugging an issue we've found that $DEBUGFS/block/$disk/state doesn't decode QUEUE_FLAG_HCTX_ACTIVE but only displays its numerical value. Add QUEUE_FLAG(HCTX_ACTIVE) to the blk_queue_flag_name array so it'll get decoded properly. Signed-off-by: Johannes Thumshirn Link: https://lore.kernel.org/r/4351076388918075bd80ef07756f9d2ce63be12c.1633332053.git.johannes.thumshirn@wdc.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

Revert "block, bfq: honor already-setup queue merges"

2021-10-06T13:55:56+00:00

[ Upstream commit ebc69e897e17373fbe1daaff1debaa77583a5284 ] This reverts commit 2d52c58b9c9bdae0ca3df6a1eab5745ab3f7d80b. We have had several folks complain that this causes hangs for them, which is especially problematic as the commit has also hit stable already. As no resolution seems to be forthcoming right now, revert the patch. Link: https://bugzilla.kernel.org/show_bug.cgi?id=214503 Fixes: 2d52c58b9c9b ("block, bfq: honor already-setup queue merges") Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

blk-cgroup: fix UAF by grabbing blkcg lock before destroying blkg pd

2021-09-30T08:11:07+00:00

[ Upstream commit 858560b27645e7e97aca37ee8f232cccd658fbd2 ] 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 Signed-off-by: Li Jinlin Acked-by: Tejun Heo Link: https://lore.kernel.org/r/20210914042605.3260596-1-lijinlin3@huawei.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: flush the integrity workqueue in blk_integrity_unregister

2021-09-30T08:11:06+00:00

[ Upstream commit 3df49967f6f1d2121b0c27c381ca1c8386b1dab9 ] When the integrity profile is unregistered there can still be integrity reads queued up which could see a NULL verify_fn as shown by the race window below: CPU0 CPU1 process_one_work nvme_validate_ns bio_integrity_verify_fn nvme_update_ns_info nvme_update_disk_info blk_integrity_unregister ---set queue->integrity as 0 bio_integrity_process --access bi->profile->verify_fn(bi is a pointer of queue->integity) Before calling blk_integrity_unregister in nvme_update_disk_info, we must make sure that there is no work item in the kintegrityd_wq. Just call blk_flush_integrity to flush the work queue so the bug can be resolved. Signed-off-by: Lihong Kou [hch: split up and shortened the changelog] Signed-off-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Link: https://lore.kernel.org/r/20210914070657.87677-3-hch@lst.de Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: check if a profile is actually registered in blk_integrity_unregister

2021-09-30T08:11:06+00:00

[ Upstream commit 783a40a1b3ac7f3714d2776fa8ac8cce3535e4f6 ] While clearing the profile itself is harmless, we really should not clear the stable writes flag if it wasn't set due to a registered integrity profile. Reported-by: Lihong Kou Signed-off-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Link: https://lore.kernel.org/r/20210914070657.87677-2-hch@lst.de Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

blk-mq: avoid to iterate over stale request

2021-09-30T08:11:05+00:00

[ Upstream commit 67f3b2f822b7e71cfc9b42dbd9f3144fa2933e0b ] blk-mq can't run allocating driver tag and updating ->rqs[tag] atomically, meantime blk-mq doesn't clear ->rqs[tag] after the driver tag is released. So there is chance to iterating over one stale request just after the tag is allocated and before updating ->rqs[tag]. scsi_host_busy_iter() calls scsi_host_check_in_flight() to count scsi in-flight requests after scsi host is blocked, so no new scsi command can be marked as SCMD_STATE_INFLIGHT. However, driver tag allocation still can be run by blk-mq core. One request is marked as SCMD_STATE_INFLIGHT, but this request may have been kept in another slot of ->rqs[], meantime the slot can be allocated out but ->rqs[] isn't updated yet. Then this in-flight request is counted twice as SCMD_STATE_INFLIGHT. This way causes trouble in handling scsi error. Fixes the issue by not iterating over stale request. Cc: linux-scsi@vger.kernel.org Cc: "Martin K. Petersen" Reported-by: luojiaxing Signed-off-by: Ming Lei Link: https://lore.kernel.org/r/20210906065003.439019-1-ming.lei@redhat.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

treewide: Change list_sort to use const pointers

2021-09-30T08:11:04+00:00

[ Upstream commit 4f0f586bf0c898233d8f316f471a21db2abd522d ] list_sort() internally casts the comparison function passed to it to a different type with constant struct list_head pointers, and uses this pointer to call the functions, which trips indirect call Control-Flow Integrity (CFI) checking. Instead of removing the consts, this change defines the list_cmp_func_t type and changes the comparison function types of all list_sort() callers to use const pointers, thus avoiding type mismatches. Suggested-by: Nick Desaulniers Signed-off-by: Sami Tolvanen Reviewed-by: Nick Desaulniers Reviewed-by: Christoph Hellwig Reviewed-by: Kees Cook Tested-by: Nick Desaulniers Tested-by: Nathan Chancellor Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20210408182843.1754385-10-samitolvanen@google.com Signed-off-by: Sasha Levin

blk-mq: allow 4x BLK_MAX_REQUEST_COUNT at blk_plug for multiple_queues

2021-09-26T12:09:01+00:00

[ Upstream commit 7f2a6a69f7ced6db8220298e0497cf60482a9d4b ] Limiting number of request to BLK_MAX_REQUEST_COUNT at blk_plug hurts performance for large md arrays. [1] shows resync speed of md array drops for md array with more than 16 HDDs. Fix this by allowing more request at plug queue. The multiple_queue flag is used to only apply higher limit to multiple queue cases. [1] https://lore.kernel.org/linux-raid/CAFDAVznS71BXW8Jxv6k9dXc2iR3ysX3iZRBww_rzA8WifBFxGg@mail.gmail.com/ Tested-by: Marcin Wanat Signed-off-by: Song Liu Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

blk-throttle: fix UAF by deleteing timer in blk_throtl_exit()

2021-09-26T12:09:01+00:00

[ Upstream commit 884f0e84f1e3195b801319c8ec3d5774e9bf2710 ] The pending timer has been set up in blk_throtl_init(). However, the timer is not deleted in blk_throtl_exit(). This means that the timer handler may still be running after freeing the timer, which would result in a use-after-free. Fix by calling del_timer_sync() to delete the timer in blk_throtl_exit(). Signed-off-by: Li Jinlin Link: https://lore.kernel.org/r/20210907121242.2885564-1-lijinlin3@huawei.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block, bfq: honor already-setup queue merges

2021-09-22T10:28:01+00:00

[ Upstream commit 2d52c58b9c9bdae0ca3df6a1eab5745ab3f7d80b ] The function bfq_setup_merge prepares the merging between two bfq_queues, say bfqq and new_bfqq. To this goal, it assigns bfqq->new_bfqq = new_bfqq. Then, each time some I/O for bfqq arrives, the process that generated that I/O is disassociated from bfqq and associated with new_bfqq (merging is actually a redirection). In this respect, bfq_setup_merge increases new_bfqq->ref in advance, adding the number of processes that are expected to be associated with new_bfqq. Unfortunately, the stable-merging mechanism interferes with this setup. After bfqq->new_bfqq has been set by bfq_setup_merge, and before all the expected processes have been associated with bfqq->new_bfqq, bfqq may happen to be stably merged with a different queue than the current bfqq->new_bfqq. In this case, bfqq->new_bfqq gets changed. So, some of the processes that have been already accounted for in the ref counter of the previous new_bfqq will not be associated with that queue. This creates an unbalance, because those references will never be decremented. This commit fixes this issue by reestablishing the previous, natural behaviour: once bfqq->new_bfqq has been set, it will not be changed until all expected redirections have occurred. Signed-off-by: Davide Zini Signed-off-by: Paolo Valente Link: https://lore.kernel.org/r/20210802141352.74353-2-paolo.valente@linaro.org Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin