| Message ID | b6a7ec3458c7a704fe34408a1243c6a13c08a313.1733227289.git.fdmanana@suse.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | btrfs: flush delalloc workers queue before stopping cleaner kthread during unmount | expand |
On Tue, Dec 03, 2024 at 12:03:02PM +0000, fdmanana@kernel.org wrote: > From: Filipe Manana <fdmanana@suse.com> > > During the unmount path, at close_ctree(), we first stop the cleaner > kthread, using kthread_stop() which frees the associated task_struct, and > then stop and destroy all the work queues. However after we stopped the > cleaner we may still have a worker from the delalloc_workers queue running > inode.c:submit_compressed_extents(), which calls btrfs_add_delayed_iput(), > which in turn tries to wake up the cleaner kthread - which was already > destroyed before, resulting in a use-after-free on the task_struct. > > Syzbot reported this with the following stack traces: > > ================================================================== > BUG: KASAN: slab-use-after-free in __lock_acquire+0x78/0x2100 kernel/locking/lockdep.c:5089 > Read of size 8 at addr ffff8880259d2818 by task kworker/u8:3/52 > > CPU: 1 UID: 0 PID: 52 Comm: kworker/u8:3 Not tainted 6.13.0-rc1-syzkaller-00002-gcdd30ebb1b9f #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 > Workqueue: btrfs-delalloc btrfs_work_helper > Call Trace: > <TASK> > __dump_stack lib/dump_stack.c:94 [inline] > dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 > print_address_description mm/kasan/report.c:378 [inline] > print_report+0x169/0x550 mm/kasan/report.c:489 > kasan_report+0x143/0x180 mm/kasan/report.c:602 > __lock_acquire+0x78/0x2100 kernel/locking/lockdep.c:5089 > lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 > class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline] > try_to_wake_up+0xc2/0x1470 kernel/sched/core.c:4205 > submit_compressed_extents+0xdf/0x16e0 fs/btrfs/inode.c:1615 > run_ordered_work fs/btrfs/async-thread.c:288 [inline] > btrfs_work_helper+0x96f/0xc40 fs/btrfs/async-thread.c:324 > process_one_work kernel/workqueue.c:3229 [inline] > process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310 > worker_thread+0x870/0xd30 kernel/workqueue.c:3391 > kthread+0x2f0/0x390 kernel/kthread.c:389 > ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > </TASK> > > Allocated by task 2: > kasan_save_stack mm/kasan/common.c:47 [inline] > kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 > unpoison_slab_object mm/kasan/common.c:319 [inline] > __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345 > kasan_slab_alloc include/linux/kasan.h:250 [inline] > slab_post_alloc_hook mm/slub.c:4104 [inline] > slab_alloc_node mm/slub.c:4153 [inline] > kmem_cache_alloc_node_noprof+0x1d9/0x380 mm/slub.c:4205 > alloc_task_struct_node kernel/fork.c:180 [inline] > dup_task_struct+0x57/0x8c0 kernel/fork.c:1113 > copy_process+0x5d1/0x3d50 kernel/fork.c:2225 > kernel_clone+0x223/0x870 kernel/fork.c:2807 > kernel_thread+0x1bc/0x240 kernel/fork.c:2869 > create_kthread kernel/kthread.c:412 [inline] > kthreadd+0x60d/0x810 kernel/kthread.c:767 > ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > Freed by task 24: > kasan_save_stack mm/kasan/common.c:47 [inline] > kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 > kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582 > poison_slab_object mm/kasan/common.c:247 [inline] > __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 > kasan_slab_free include/linux/kasan.h:233 [inline] > slab_free_hook mm/slub.c:2338 [inline] > slab_free mm/slub.c:4598 [inline] > kmem_cache_free+0x195/0x410 mm/slub.c:4700 > put_task_struct include/linux/sched/task.h:144 [inline] > delayed_put_task_struct+0x125/0x300 kernel/exit.c:227 > rcu_do_batch kernel/rcu/tree.c:2567 [inline] > rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2823 > handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:554 > run_ksoftirqd+0xca/0x130 kernel/softirq.c:943 > smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164 > kthread+0x2f0/0x390 kernel/kthread.c:389 > ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > Last potentially related work creation: > kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47 > __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:544 > __call_rcu_common kernel/rcu/tree.c:3086 [inline] > call_rcu+0x167/0xa70 kernel/rcu/tree.c:3190 > context_switch kernel/sched/core.c:5372 [inline] > __schedule+0x1803/0x4be0 kernel/sched/core.c:6756 > __schedule_loop kernel/sched/core.c:6833 [inline] > schedule+0x14b/0x320 kernel/sched/core.c:6848 > schedule_timeout+0xb0/0x290 kernel/time/sleep_timeout.c:75 > do_wait_for_common kernel/sched/completion.c:95 [inline] > __wait_for_common kernel/sched/completion.c:116 [inline] > wait_for_common kernel/sched/completion.c:127 [inline] > wait_for_completion+0x355/0x620 kernel/sched/completion.c:148 > kthread_stop+0x19e/0x640 kernel/kthread.c:712 > close_ctree+0x524/0xd60 fs/btrfs/disk-io.c:4328 > generic_shutdown_super+0x139/0x2d0 fs/super.c:642 > kill_anon_super+0x3b/0x70 fs/super.c:1237 > btrfs_kill_super+0x41/0x50 fs/btrfs/super.c:2112 > deactivate_locked_super+0xc4/0x130 fs/super.c:473 > cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1373 > task_work_run+0x24f/0x310 kernel/task_work.c:239 > ptrace_notify+0x2d2/0x380 kernel/signal.c:2503 > ptrace_report_syscall include/linux/ptrace.h:415 [inline] > ptrace_report_syscall_exit include/linux/ptrace.h:477 [inline] > syscall_exit_work+0xc7/0x1d0 kernel/entry/common.c:173 > syscall_exit_to_user_mode_prepare kernel/entry/common.c:200 [inline] > __syscall_exit_to_user_mode_work kernel/entry/common.c:205 [inline] > syscall_exit_to_user_mode+0x24a/0x340 kernel/entry/common.c:218 > do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > The buggy address belongs to the object at ffff8880259d1e00 > which belongs to the cache task_struct of size 7424 > The buggy address is located 2584 bytes inside of > freed 7424-byte region [ffff8880259d1e00, ffff8880259d3b00) > > The buggy address belongs to the physical page: > page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x259d0 > head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 > memcg:ffff88802f4b56c1 > flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) > page_type: f5(slab) > raw: 00fff00000000040 ffff88801bafe500 dead000000000100 dead000000000122 > raw: 0000000000000000 0000000000040004 00000001f5000000 ffff88802f4b56c1 > head: 00fff00000000040 ffff88801bafe500 dead000000000100 dead000000000122 > head: 0000000000000000 0000000000040004 00000001f5000000 ffff88802f4b56c1 > head: 00fff00000000003 ffffea0000967401 ffffffffffffffff 0000000000000000 > head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000 > page dumped because: kasan: bad access detected > page_owner tracks the page as allocated > page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 12, tgid 12 (kworker/u8:1), ts 7328037942, free_ts 0 > set_page_owner include/linux/page_owner.h:32 [inline] > post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1556 > prep_new_page mm/page_alloc.c:1564 [inline] > get_page_from_freelist+0x3651/0x37a0 mm/page_alloc.c:3474 > __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4751 > alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265 > alloc_slab_page+0x6a/0x140 mm/slub.c:2408 > allocate_slab+0x5a/0x2f0 mm/slub.c:2574 > new_slab mm/slub.c:2627 [inline] > ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3815 > __slab_alloc+0x58/0xa0 mm/slub.c:3905 > __slab_alloc_node mm/slub.c:3980 [inline] > slab_alloc_node mm/slub.c:4141 [inline] > kmem_cache_alloc_node_noprof+0x269/0x380 mm/slub.c:4205 > alloc_task_struct_node kernel/fork.c:180 [inline] > dup_task_struct+0x57/0x8c0 kernel/fork.c:1113 > copy_process+0x5d1/0x3d50 kernel/fork.c:2225 > kernel_clone+0x223/0x870 kernel/fork.c:2807 > user_mode_thread+0x132/0x1a0 kernel/fork.c:2885 > call_usermodehelper_exec_work+0x5c/0x230 kernel/umh.c:171 > process_one_work kernel/workqueue.c:3229 [inline] > process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310 > worker_thread+0x870/0xd30 kernel/workqueue.c:3391 > page_owner free stack trace missing > > Memory state around the buggy address: > ffff8880259d2700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8880259d2780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > >ffff8880259d2800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ^ > ffff8880259d2880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8880259d2900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ================================================================== > > Fix this by flushing the delalloc workers queue before stopping the > cleaner kthread. > > Reported-by: syzbot+b7cf50a0c173770dcb14@syzkaller.appspotmail.com > Link: https://lore.kernel.org/linux-btrfs/674ed7e8.050a0220.48a03.0031.GAE@google.com/ > Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com>
在 2024/12/3 22:33, fdmanana@kernel.org 写道: > From: Filipe Manana <fdmanana@suse.com> > > During the unmount path, at close_ctree(), we first stop the cleaner > kthread, using kthread_stop() which frees the associated task_struct, and > then stop and destroy all the work queues. However after we stopped the > cleaner we may still have a worker from the delalloc_workers queue running > inode.c:submit_compressed_extents(), which calls btrfs_add_delayed_iput(), > which in turn tries to wake up the cleaner kthread - which was already > destroyed before, resulting in a use-after-free on the task_struct. > > Syzbot reported this with the following stack traces: > > ================================================================== > BUG: KASAN: slab-use-after-free in __lock_acquire+0x78/0x2100 kernel/locking/lockdep.c:5089 > Read of size 8 at addr ffff8880259d2818 by task kworker/u8:3/52 > > CPU: 1 UID: 0 PID: 52 Comm: kworker/u8:3 Not tainted 6.13.0-rc1-syzkaller-00002-gcdd30ebb1b9f #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 > Workqueue: btrfs-delalloc btrfs_work_helper > Call Trace: > <TASK> > __dump_stack lib/dump_stack.c:94 [inline] > dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 > print_address_description mm/kasan/report.c:378 [inline] > print_report+0x169/0x550 mm/kasan/report.c:489 > kasan_report+0x143/0x180 mm/kasan/report.c:602 > __lock_acquire+0x78/0x2100 kernel/locking/lockdep.c:5089 > lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 > __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] > _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 > class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline] > try_to_wake_up+0xc2/0x1470 kernel/sched/core.c:4205 > submit_compressed_extents+0xdf/0x16e0 fs/btrfs/inode.c:1615 > run_ordered_work fs/btrfs/async-thread.c:288 [inline] > btrfs_work_helper+0x96f/0xc40 fs/btrfs/async-thread.c:324 > process_one_work kernel/workqueue.c:3229 [inline] > process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310 > worker_thread+0x870/0xd30 kernel/workqueue.c:3391 > kthread+0x2f0/0x390 kernel/kthread.c:389 > ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > </TASK> > > Allocated by task 2: > kasan_save_stack mm/kasan/common.c:47 [inline] > kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 > unpoison_slab_object mm/kasan/common.c:319 [inline] > __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345 > kasan_slab_alloc include/linux/kasan.h:250 [inline] > slab_post_alloc_hook mm/slub.c:4104 [inline] > slab_alloc_node mm/slub.c:4153 [inline] > kmem_cache_alloc_node_noprof+0x1d9/0x380 mm/slub.c:4205 > alloc_task_struct_node kernel/fork.c:180 [inline] > dup_task_struct+0x57/0x8c0 kernel/fork.c:1113 > copy_process+0x5d1/0x3d50 kernel/fork.c:2225 > kernel_clone+0x223/0x870 kernel/fork.c:2807 > kernel_thread+0x1bc/0x240 kernel/fork.c:2869 > create_kthread kernel/kthread.c:412 [inline] > kthreadd+0x60d/0x810 kernel/kthread.c:767 > ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > Freed by task 24: > kasan_save_stack mm/kasan/common.c:47 [inline] > kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 > kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582 > poison_slab_object mm/kasan/common.c:247 [inline] > __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 > kasan_slab_free include/linux/kasan.h:233 [inline] > slab_free_hook mm/slub.c:2338 [inline] > slab_free mm/slub.c:4598 [inline] > kmem_cache_free+0x195/0x410 mm/slub.c:4700 > put_task_struct include/linux/sched/task.h:144 [inline] > delayed_put_task_struct+0x125/0x300 kernel/exit.c:227 > rcu_do_batch kernel/rcu/tree.c:2567 [inline] > rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2823 > handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:554 > run_ksoftirqd+0xca/0x130 kernel/softirq.c:943 > smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164 > kthread+0x2f0/0x390 kernel/kthread.c:389 > ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > Last potentially related work creation: > kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47 > __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:544 > __call_rcu_common kernel/rcu/tree.c:3086 [inline] > call_rcu+0x167/0xa70 kernel/rcu/tree.c:3190 > context_switch kernel/sched/core.c:5372 [inline] > __schedule+0x1803/0x4be0 kernel/sched/core.c:6756 > __schedule_loop kernel/sched/core.c:6833 [inline] > schedule+0x14b/0x320 kernel/sched/core.c:6848 > schedule_timeout+0xb0/0x290 kernel/time/sleep_timeout.c:75 > do_wait_for_common kernel/sched/completion.c:95 [inline] > __wait_for_common kernel/sched/completion.c:116 [inline] > wait_for_common kernel/sched/completion.c:127 [inline] > wait_for_completion+0x355/0x620 kernel/sched/completion.c:148 > kthread_stop+0x19e/0x640 kernel/kthread.c:712 > close_ctree+0x524/0xd60 fs/btrfs/disk-io.c:4328 > generic_shutdown_super+0x139/0x2d0 fs/super.c:642 > kill_anon_super+0x3b/0x70 fs/super.c:1237 > btrfs_kill_super+0x41/0x50 fs/btrfs/super.c:2112 > deactivate_locked_super+0xc4/0x130 fs/super.c:473 > cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1373 > task_work_run+0x24f/0x310 kernel/task_work.c:239 > ptrace_notify+0x2d2/0x380 kernel/signal.c:2503 > ptrace_report_syscall include/linux/ptrace.h:415 [inline] > ptrace_report_syscall_exit include/linux/ptrace.h:477 [inline] > syscall_exit_work+0xc7/0x1d0 kernel/entry/common.c:173 > syscall_exit_to_user_mode_prepare kernel/entry/common.c:200 [inline] > __syscall_exit_to_user_mode_work kernel/entry/common.c:205 [inline] > syscall_exit_to_user_mode+0x24a/0x340 kernel/entry/common.c:218 > do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > The buggy address belongs to the object at ffff8880259d1e00 > which belongs to the cache task_struct of size 7424 > The buggy address is located 2584 bytes inside of > freed 7424-byte region [ffff8880259d1e00, ffff8880259d3b00) > > The buggy address belongs to the physical page: > page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x259d0 > head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 > memcg:ffff88802f4b56c1 > flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) > page_type: f5(slab) > raw: 00fff00000000040 ffff88801bafe500 dead000000000100 dead000000000122 > raw: 0000000000000000 0000000000040004 00000001f5000000 ffff88802f4b56c1 > head: 00fff00000000040 ffff88801bafe500 dead000000000100 dead000000000122 > head: 0000000000000000 0000000000040004 00000001f5000000 ffff88802f4b56c1 > head: 00fff00000000003 ffffea0000967401 ffffffffffffffff 0000000000000000 > head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000 > page dumped because: kasan: bad access detected > page_owner tracks the page as allocated > page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 12, tgid 12 (kworker/u8:1), ts 7328037942, free_ts 0 > set_page_owner include/linux/page_owner.h:32 [inline] > post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1556 > prep_new_page mm/page_alloc.c:1564 [inline] > get_page_from_freelist+0x3651/0x37a0 mm/page_alloc.c:3474 > __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4751 > alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265 > alloc_slab_page+0x6a/0x140 mm/slub.c:2408 > allocate_slab+0x5a/0x2f0 mm/slub.c:2574 > new_slab mm/slub.c:2627 [inline] > ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3815 > __slab_alloc+0x58/0xa0 mm/slub.c:3905 > __slab_alloc_node mm/slub.c:3980 [inline] > slab_alloc_node mm/slub.c:4141 [inline] > kmem_cache_alloc_node_noprof+0x269/0x380 mm/slub.c:4205 > alloc_task_struct_node kernel/fork.c:180 [inline] > dup_task_struct+0x57/0x8c0 kernel/fork.c:1113 > copy_process+0x5d1/0x3d50 kernel/fork.c:2225 > kernel_clone+0x223/0x870 kernel/fork.c:2807 > user_mode_thread+0x132/0x1a0 kernel/fork.c:2885 > call_usermodehelper_exec_work+0x5c/0x230 kernel/umh.c:171 > process_one_work kernel/workqueue.c:3229 [inline] > process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310 > worker_thread+0x870/0xd30 kernel/workqueue.c:3391 > page_owner free stack trace missing > > Memory state around the buggy address: > ffff8880259d2700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8880259d2780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > >ffff8880259d2800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ^ > ffff8880259d2880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8880259d2900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ================================================================== > > Fix this by flushing the delalloc workers queue before stopping the > cleaner kthread. > > Reported-by: syzbot+b7cf50a0c173770dcb14@syzkaller.appspotmail.com > Link: https://lore.kernel.org/linux-btrfs/674ed7e8.050a0220.48a03.0031.GAE@google.com/ > Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Thanks, Qu > --- > fs/btrfs/disk-io.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c > index 814320948645..eff0dd1ae62f 100644 > --- a/fs/btrfs/disk-io.c > +++ b/fs/btrfs/disk-io.c > @@ -4262,6 +4262,15 @@ void __cold close_ctree(struct btrfs_fs_info *fs_info) > * already the cleaner, but below we run all pending delayed iputs. > */ > btrfs_flush_workqueue(fs_info->fixup_workers); > + /* > + * Similar case here, we have to wait for delalloc workers before we > + * proceed below and stop the cleaner kthread, otherwise we trigger a > + * use-after-tree on the cleaner kthread task_struct when a delalloc > + * worker running submit_compressed_extents() adds a delayed iput, which > + * does a wake up on the cleaner kthread, which was already freed below > + * when we call kthread_stop(). > + */ > + btrfs_flush_workqueue(fs_info->delalloc_workers); > > /* > * After we parked the cleaner kthread, ordered extents may have
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 814320948645..eff0dd1ae62f 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -4262,6 +4262,15 @@ void __cold close_ctree(struct btrfs_fs_info *fs_info) * already the cleaner, but below we run all pending delayed iputs. */ btrfs_flush_workqueue(fs_info->fixup_workers); + /* + * Similar case here, we have to wait for delalloc workers before we + * proceed below and stop the cleaner kthread, otherwise we trigger a + * use-after-tree on the cleaner kthread task_struct when a delalloc + * worker running submit_compressed_extents() adds a delayed iput, which + * does a wake up on the cleaner kthread, which was already freed below + * when we call kthread_stop(). + */ + btrfs_flush_workqueue(fs_info->delalloc_workers); /* * After we parked the cleaner kthread, ordered extents may have