================================================================== BUG: KASAN: slab-use-after-free in __ref_is_percpu include/linux/percpu-refcount.h:174 [inline] BUG: KASAN: slab-use-after-free in percpu_ref_put_many include/linux/percpu-refcount.h:332 [inline] BUG: KASAN: slab-use-after-free in percpu_ref_put+0xda/0x250 include/linux/percpu-refcount.h:351 Read of size 8 at addr ffff8880339b80b0 by task kworker/u4:2/26 CPU: 0 UID: 0 PID: 26 Comm: kworker/u4:2 Not tainted 6.11.0-syzkaller-11728-gad46e8f95e93 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: loop0 loop_rootcg_workfn Call Trace: __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:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 __ref_is_percpu include/linux/percpu-refcount.h:174 [inline] percpu_ref_put_many include/linux/percpu-refcount.h:332 [inline] percpu_ref_put+0xda/0x250 include/linux/percpu-refcount.h:351 blk_update_request+0x5e5/0x1160 block/blk-mq.c:923 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1051 loop_handle_cmd drivers/block/loop.c:1927 [inline] loop_process_work+0x1c10/0x2170 drivers/block/loop.c:1945 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 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 Allocated by task 5110: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:257 [inline] __kmalloc_cache_noprof+0x19c/0x2c0 mm/slub.c:4296 kmalloc_noprof include/linux/slab.h:878 [inline] kzalloc_noprof include/linux/slab.h:1014 [inline] __bch2_dev_alloc+0x57/0xa60 fs/bcachefs/super.c:1289 bch2_dev_alloc+0xd4/0x170 fs/bcachefs/super.c:1359 bch2_fs_alloc fs/bcachefs/super.c:939 [inline] bch2_fs_open+0x2e3f/0x2f80 fs/bcachefs/super.c:2050 bch2_fs_get_tree+0x738/0x1710 fs/bcachefs/fs.c:2058 vfs_get_tree+0x90/0x2b0 fs/super.c:1800 do_new_mount+0x2be/0xb40 fs/namespace.c:3507 do_mount fs/namespace.c:3847 [inline] __do_sys_mount fs/namespace.c:4055 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4032 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5110: 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:579 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:230 [inline] slab_free_hook mm/slub.c:2343 [inline] slab_free mm/slub.c:4580 [inline] kfree+0x1a0/0x440 mm/slub.c:4728 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x22f/0x480 lib/kobject.c:737 bch2_fs_free+0x27b/0x3c0 fs/bcachefs/super.c:667 bch2_fs_get_tree+0xd9f/0x1710 fs/bcachefs/fs.c:2166 vfs_get_tree+0x90/0x2b0 fs/super.c:1800 do_new_mount+0x2be/0xb40 fs/namespace.c:3507 do_mount fs/namespace.c:3847 [inline] __do_sys_mount fs/namespace.c:4055 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4032 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f 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:541 insert_work+0x3e/0x330 kernel/workqueue.c:2183 __queue_work+0xc8b/0xf50 kernel/workqueue.c:2339 queue_work_on+0x1c2/0x380 kernel/workqueue.c:2390 queue_work include/linux/workqueue.h:662 [inline] bch2_dev_do_invalidates+0x17a/0x1f0 fs/bcachefs/alloc_background.c:2150 bch2_do_invalidates+0x29/0x60 fs/bcachefs/alloc_background.c:2161 __bch2_fs_read_write+0x34c/0x370 fs/bcachefs/super.c:498 bch2_run_recovery_pass+0xf0/0x1e0 fs/bcachefs/recovery_passes.c:185 bch2_run_recovery_passes+0x387/0x870 fs/bcachefs/recovery_passes.c:232 bch2_fs_recovery+0x24f9/0x38b0 fs/bcachefs/recovery.c:859 bch2_fs_start+0x356/0x5b0 fs/bcachefs/super.c:1037 bch2_fs_get_tree+0xd68/0x1710 fs/bcachefs/fs.c:2071 vfs_get_tree+0x90/0x2b0 fs/super.c:1800 do_new_mount+0x2be/0xb40 fs/namespace.c:3507 do_mount fs/namespace.c:3847 [inline] __do_sys_mount fs/namespace.c:4055 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4032 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Second to 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:541 insert_work+0x3e/0x330 kernel/workqueue.c:2183 __queue_work+0xc8b/0xf50 kernel/workqueue.c:2339 queue_work_on+0x1c2/0x380 kernel/workqueue.c:2390 queue_work include/linux/workqueue.h:662 [inline] bch2_dev_do_discards+0x17a/0x1f0 fs/bcachefs/alloc_background.c:1892 bch2_do_discards+0x29/0x60 fs/bcachefs/alloc_background.c:1903 __bch2_fs_read_write+0x344/0x370 fs/bcachefs/super.c:497 bch2_run_recovery_pass+0xf0/0x1e0 fs/bcachefs/recovery_passes.c:185 bch2_run_recovery_passes+0x387/0x870 fs/bcachefs/recovery_passes.c:232 bch2_fs_recovery+0x24f9/0x38b0 fs/bcachefs/recovery.c:859 bch2_fs_start+0x356/0x5b0 fs/bcachefs/super.c:1037 bch2_fs_get_tree+0xd68/0x1710 fs/bcachefs/fs.c:2071 vfs_get_tree+0x90/0x2b0 fs/super.c:1800 do_new_mount+0x2be/0xb40 fs/namespace.c:3507 do_mount fs/namespace.c:3847 [inline] __do_sys_mount fs/namespace.c:4055 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4032 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880339b8000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 176 bytes inside of freed 4096-byte region [ffff8880339b8000, ffff8880339b9000) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x339b8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 04fff00000000040 ffff88801ac42140 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000040004 00000001f5000000 0000000000000000 head: 04fff00000000040 ffff88801ac42140 0000000000000000 dead000000000001 head: 0000000000000000 0000000000040004 00000001f5000000 0000000000000000 head: 04fff00000000003 ffffea0000ce6e01 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 1, tgid 1 (swapper/0), ts 9538331265, free_ts 9497110077 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537 prep_new_page mm/page_alloc.c:1545 [inline] get_page_from_freelist+0x3045/0x3190 mm/page_alloc.c:3457 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4733 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265 alloc_slab_page+0x6a/0x120 mm/slub.c:2413 allocate_slab+0x5a/0x2f0 mm/slub.c:2579 new_slab mm/slub.c:2632 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3819 __slab_alloc+0x58/0xa0 mm/slub.c:3909 __slab_alloc_node mm/slub.c:3962 [inline] slab_alloc_node mm/slub.c:4123 [inline] __kmalloc_cache_noprof+0x1d5/0x2c0 mm/slub.c:4291 kmalloc_noprof include/linux/slab.h:878 [inline] kzalloc_noprof include/linux/slab.h:1014 [inline] kobject_uevent_env+0x28b/0x8e0 lib/kobject_uevent.c:540 device_add+0x63b/0xbf0 drivers/base/core.c:3656 device_create_groups_vargs drivers/base/core.c:4367 [inline] device_create+0x257/0x2e0 drivers/base/core.c:4406 bdi_register_va+0x8b/0x760 mm/backing-dev.c:1094 bdi_register+0xd5/0x120 mm/backing-dev.c:1126 device_add_disk+0x859/0x1000 block/genhd.c:494 add_disk include/linux/blkdev.h:732 [inline] brd_alloc+0x4da/0x770 drivers/block/brd.c:372 page last free pid 1 tgid 1 stack trace: create_dummy_stack mm/page_owner.c:94 [inline] register_dummy_stack+0x8a/0xe0 mm/page_owner.c:100 init_page_owner+0x3e/0x970 mm/page_owner.c:118 invoke_init_callbacks mm/page_ext.c:148 [inline] page_ext_init+0x731/0x790 mm/page_ext.c:497 mm_core_init+0x4c/0x60 mm/mm_init.c:2667 Memory state around the buggy address: ffff8880339b7f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880339b8000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880339b8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880339b8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880339b8180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================