================================================================== 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 ffff88804dc1e0b0 by task kworker/u4:5/1033 CPU: 0 UID: 0 PID: 1033 Comm: kworker/u4:5 Not tainted 6.14.0-rc4-syzkaller-00073-g5394eea10651 #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:408 [inline] print_report+0x16e/0x5b0 mm/kasan/report.c:521 kasan_report+0x143/0x180 mm/kasan/report.c:634 __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:983 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1145 loop_handle_cmd drivers/block/loop.c:1946 [inline] loop_process_work+0x1bc8/0x21c0 drivers/block/loop.c:1964 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Allocated by task 5346: 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:260 [inline] __kmalloc_cache_noprof+0x243/0x390 mm/slub.c:4325 kmalloc_noprof include/linux/slab.h:901 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] __bch2_dev_alloc+0x57/0xa60 fs/bcachefs/super.c:1310 bch2_dev_alloc+0xd4/0x170 fs/bcachefs/super.c:1377 bch2_fs_alloc fs/bcachefs/super.c:942 [inline] bch2_fs_open+0x30aa/0x31e0 fs/bcachefs/super.c:2064 bch2_fs_get_tree+0x738/0x17a0 fs/bcachefs/fs.c:2190 vfs_get_tree+0x90/0x2b0 fs/super.c:1814 do_new_mount+0x2be/0xb40 fs/namespace.c:3560 do_mount fs/namespace.c:3900 [inline] __do_sys_mount fs/namespace.c:4111 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4088 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 5346: 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:576 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:2353 [inline] slab_free mm/slub.c:4609 [inline] kfree+0x196/0x430 mm/slub.c:4757 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:680 bch2_fs_get_tree+0xdee/0x17a0 fs/bcachefs/fs.c:2299 vfs_get_tree+0x90/0x2b0 fs/super.c:1814 do_new_mount+0x2be/0xb40 fs/namespace.c:3560 do_mount fs/namespace.c:3900 [inline] __do_sys_mount fs/namespace.c:4111 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4088 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+0xaa/0xc0 mm/kasan/generic.c:548 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:1952 bch2_do_discards+0x29/0x60 fs/bcachefs/alloc_background.c:1963 journal_write_done+0x78b/0xea0 fs/bcachefs/journal_io.c:1657 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Second to last potentially related work creation: kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xaa/0xc0 mm/kasan/generic.c:548 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:1952 bch2_do_discards+0x29/0x60 fs/bcachefs/alloc_background.c:1963 journal_write_done+0x78b/0xea0 fs/bcachefs/journal_io.c:1657 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 The buggy address belongs to the object at ffff88804dc1e000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 176 bytes inside of freed 4096-byte region [ffff88804dc1e000, ffff88804dc1f000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4dc18 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 04fff00000000040 ffff88801b042140 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000 head: 04fff00000000040 ffff88801b042140 dead000000000122 0000000000000000 head: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000 head: 04fff00000000003 ffffea0001370601 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 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5350, tgid 5350 (udevd), ts 319742173693, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551 prep_new_page mm/page_alloc.c:1559 [inline] get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3477 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4739 alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:2423 [inline] allocate_slab+0x8f/0x3a0 mm/slub.c:2587 new_slab mm/slub.c:2640 [inline] ___slab_alloc+0xc27/0x14a0 mm/slub.c:3826 __slab_alloc+0x58/0xa0 mm/slub.c:3916 __slab_alloc_node mm/slub.c:3991 [inline] slab_alloc_node mm/slub.c:4152 [inline] __do_kmalloc_node mm/slub.c:4293 [inline] __kmalloc_noprof+0x2e6/0x4c0 mm/slub.c:4306 kmalloc_noprof include/linux/slab.h:905 [inline] tomoyo_realpath_from_path+0xcf/0x5e0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x258/0x4f0 security/tomoyo/file.c:771 security_file_open+0xac/0x250 security/security.c:3114 do_dentry_open+0x320/0x1960 fs/open.c:933 vfs_open+0x3b/0x370 fs/open.c:1086 do_open fs/namei.c:3830 [inline] path_openat+0x2c81/0x3590 fs/namei.c:3989 do_filp_open+0x27f/0x4e0 fs/namei.c:4016 do_sys_openat2+0x13e/0x1d0 fs/open.c:1428 page_owner free stack trace missing Memory state around the buggy address: ffff88804dc1df80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88804dc1e000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88804dc1e080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88804dc1e100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804dc1e180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================