program: mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./config\x00', 0x1ff) mount(0x0, &(0x7f0000000000)='./config\x00', &(0x7f0000000400)='configfs\x00', 0x0, 0x0) r0 = bpf$MAP_CREATE(0x0, &(0x7f0000000500)=@base={0x1e, 0x0, 0x4, 0x2, 0x0, 0x1}, 0x48) bpf$MAP_GET_NEXT_KEY(0x4, &(0x7f0000000080)={r0, 0x0, 0x0}, 0x20) mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./config/usb_gadget/g1\x00', 0x1ff) mkdirat(0xffffffffffffff9c, &(0x7f0000000100)='./config/usb_gadget/g1/functions/uac1_legacy.usb0\x00', 0x1ff) mkdirat(0xffffffffffffff9c, &(0x7f0000000180)='./config/usb_gadget/g1/configs/c.1\x00', 0x1ff) symlinkat(&(0x7f0000000200)='./config/usb_gadget/g1/functions/uac1_legacy.usb0\x00', 0xffffffffffffff9c, &(0x7f0000000280)='./config/usb_gadget/g1/configs/c.1/uac1_legacy.usb0\x00') r1 = openat(0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/UDC\x00', 0x1, 0x0) write(r1, &(0x7f0000000400)='dummy_udc.0\n\x00', 0xc) nanosleep(&(0x7f0000000500)={0x0, 0x2faf080}, 0x0) mkdirat(0xffffffffffffff9c, &(0x7f0000000000)='./config\x00', 0x1ff) (async) mount(0x0, &(0x7f0000000000)='./config\x00', &(0x7f0000000400)='configfs\x00', 0x0, 0x0) (async) bpf$MAP_CREATE(0x0, &(0x7f0000000500)=@base={0x1e, 0x0, 0x4, 0x2, 0x0, 0x1}, 0x48) (async) bpf$MAP_GET_NEXT_KEY(0x4, &(0x7f0000000080)={r0, 0x0, 0x0}, 0x20) (async) mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./config/usb_gadget/g1\x00', 0x1ff) (async) mkdirat(0xffffffffffffff9c, &(0x7f0000000100)='./config/usb_gadget/g1/functions/uac1_legacy.usb0\x00', 0x1ff) (async) mkdirat(0xffffffffffffff9c, &(0x7f0000000180)='./config/usb_gadget/g1/configs/c.1\x00', 0x1ff) (async) symlinkat(&(0x7f0000000200)='./config/usb_gadget/g1/functions/uac1_legacy.usb0\x00', 0xffffffffffffff9c, &(0x7f0000000280)='./config/usb_gadget/g1/configs/c.1/uac1_legacy.usb0\x00') (async) openat(0xffffffffffffff9c, &(0x7f0000000300)='./config/usb_gadget/g1/UDC\x00', 0x1, 0x0) (async) write(r1, &(0x7f0000000400)='dummy_udc.0\n\x00', 0xc) (async) nanosleep(&(0x7f0000000500)={0x0, 0x2faf080}, 0x0) (async) [ 86.860149][ T5288] Bluetooth: hci0: command tx timeout [ 86.995104][ T5324] configfs-gadget.g1 gadget.0: Hardware params: access 3, format 2, channels 2, rate 48000 [ 87.017401][ T5324] udc dummy_udc.0: failed to start g1: -19 [ 87.027119][ T5324] UDC core: g1: couldn't find an available UDC or it's busy [ 87.075196][ T5325] ================================================================== [ 87.078456][ T5325] BUG: KASAN: slab-use-after-free in filp_flush+0x31/0x190 [ 87.081314][ T5325] Read of size 8 at addr ffff8880122b5a18 by task syz.0.0/5325 [ 87.084370][ T5325] [ 87.085402][ T5325] CPU: 0 UID: 0 PID: 5325 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) [ 87.085412][ T5325] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 87.085416][ T5325] Call Trace: [ 87.085421][ T5325] [ 87.085425][ T5325] dump_stack_lvl+0xe8/0x150 [ 87.085441][ T5325] print_address_description+0x55/0x1e0 [ 87.085455][ T5325] ? filp_flush+0x31/0x190 [ 87.085467][ T5325] print_report+0x58/0x70 [ 87.085480][ T5325] kasan_report+0x117/0x150 [ 87.085493][ T5325] ? filp_flush+0x31/0x190 [ 87.085506][ T5325] kasan_check_range+0x264/0x2c0 [ 87.085519][ T5325] filp_flush+0x31/0x190 [ 87.085527][ T5325] filp_close+0x1d/0x40 [ 87.085534][ T5325] gaudio_cleanup+0x54/0xf0 [ 87.085590][ T5325] f_audio_bind+0x4a0/0x630 [ 87.085601][ T5325] ? __pfx_f_audio_bind+0x10/0x10 [ 87.085611][ T5325] ? rcu_is_watching+0x15/0xb0 [ 87.085621][ T5325] ? usb_gadget_set_selfpowered+0xf5/0x260 [ 87.085632][ T5325] usb_add_function+0x2e1/0x9f0 [ 87.085645][ T5325] ? check_remote_wakeup_config+0x58/0x1c0 [ 87.085655][ T5325] configfs_composite_bind+0xde0/0x1410 [ 87.085671][ T5325] ? __pfx_configfs_composite_bind+0x10/0x10 [ 87.085684][ T5325] gadget_bind_driver+0x2ca/0x9e0 [ 87.085698][ T5325] ? __pfx_gadget_bind_driver+0x10/0x10 [ 87.085709][ T5325] really_probe+0x254/0xae0 [ 87.085751][ T5325] __driver_probe_device+0x1e8/0x360 [ 87.085758][ T5325] driver_probe_device+0x4f/0x240 [ 87.085765][ T5325] __driver_attach+0x339/0x600 [ 87.085775][ T5325] bus_for_each_dev+0x23b/0x2c0 [ 87.085788][ T5325] ? __pfx___driver_attach+0x10/0x10 [ 87.085797][ T5325] ? __pfx_bus_for_each_dev+0x10/0x10 [ 87.085810][ T5325] ? do_raw_spin_unlock+0x4d/0x210 [ 87.085823][ T5325] bus_add_driver+0x345/0x670 [ 87.085837][ T5325] driver_register+0x23a/0x320 [ 87.085849][ T5325] usb_gadget_register_driver_owner+0xf9/0x270 [ 87.085862][ T5325] gadget_dev_desc_UDC_store+0x1c9/0x2f0 [ 87.085874][ T5325] ? __pfx_gadget_dev_desc_UDC_store+0x10/0x10 [ 87.085886][ T5325] configfs_write_iter+0x337/0x430 [ 87.085900][ T5325] vfs_write+0x612/0xba0 [ 87.085915][ T5325] ? __pfx_vfs_write+0x10/0x10 [ 87.085930][ T5325] ? __fget_files+0x2a/0x420 [ 87.085945][ T5325] ksys_write+0x150/0x270 [ 87.085959][ T5325] ? __pfx_ksys_write+0x10/0x10 [ 87.085972][ T5325] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 87.085983][ T5325] do_syscall_64+0x174/0x580 [ 87.085995][ T5325] ? trace_irq_disable+0x3b/0x140 [ 87.086008][ T5325] ? clear_bhb_loop+0x40/0x90 [ 87.086019][ T5325] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 87.086030][ T5325] RIP: 0033:0x7f94a6d9e019 [ 87.086040][ T5325] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 [ 87.086046][ T5325] RSP: 002b:00007f94a7d1bfe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 87.086054][ T5325] RAX: ffffffffffffffda RBX: 00007f94a7026090 RCX: 00007f94a6d9e019 [ 87.086059][ T5325] RDX: 000000000000000c RSI: 0000200000000400 RDI: 0000000000000004 [ 87.086063][ T5325] RBP: 00007f94a6e3500c R08: 0000000000000000 R09: 0000000000000000 [ 87.086068][ T5325] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 87.086072][ T5325] R13: 00007f94a7026128 R14: 00007f94a7026090 R15: 00007fff4f9549e8 [ 87.086079][ T5325] [ 87.086081][ T5325] [ 87.222289][ T5325] Allocated by task 5324: [ 87.224108][ T5325] kasan_save_track+0x3e/0x80 [ 87.226198][ T5325] __kasan_slab_alloc+0x6c/0x80 [ 87.228272][ T5325] kmem_cache_alloc_noprof+0x2a0/0x5f0 [ 87.230625][ T5325] alloc_empty_file+0x5b/0x1d0 [ 87.232679][ T5325] path_openat+0x8f/0x3830 [ 87.234629][ T5325] do_file_open+0x23e/0x4a0 [ 87.236504][ T5325] filp_open+0x16d/0x1d0 [ 87.238294][ T5325] gaudio_setup+0x11b/0xf10 [ 87.240243][ T5325] f_audio_bind+0x137/0x630 [ 87.242186][ T5325] usb_add_function+0x2e1/0x9f0 [ 87.244096][ T5325] configfs_composite_bind+0xde0/0x1410 [ 87.246255][ T5325] gadget_bind_driver+0x2ca/0x9e0 [ 87.248307][ T5325] really_probe+0x254/0xae0 [ 87.250217][ T5325] __driver_probe_device+0x1e8/0x360 [ 87.252438][ T5325] driver_probe_device+0x4f/0x240 [ 87.254465][ T5325] __driver_attach+0x339/0x600 [ 87.256433][ T5325] bus_for_each_dev+0x23b/0x2c0 [ 87.258452][ T5325] bus_add_driver+0x345/0x670 [ 87.260415][ T5325] driver_register+0x23a/0x320 [ 87.262424][ T5325] usb_gadget_register_driver_owner+0xf9/0x270 [ 87.264878][ T5325] gadget_dev_desc_UDC_store+0x1c9/0x2f0 [ 87.267394][ T5325] configfs_write_iter+0x337/0x430 [ 87.269617][ T5325] vfs_write+0x612/0xba0 [ 87.271517][ T5325] ksys_write+0x150/0x270 [ 87.273430][ T5325] do_syscall_64+0x174/0x580 [ 87.275411][ T5325] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 87.277933][ T5325] [ 87.278914][ T5325] Freed by task 0: [ 87.280517][ T5325] kasan_save_track+0x3e/0x80 [ 87.282431][ T5325] kasan_save_free_info+0x40/0x50 [ 87.284527][ T5325] __kasan_slab_free+0x5c/0x80 [ 87.286614][ T5325] slab_free_after_rcu_debug+0x12a/0x220 [ 87.288973][ T5325] rcu_core+0x78b/0x10a0 [ 87.290734][ T5325] handle_softirqs+0x225/0x840 [ 87.292759][ T5325] __irq_exit_rcu+0xca/0x220 [ 87.294719][ T5325] irq_exit_rcu+0x9/0x30 [ 87.296600][ T5325] sysvec_apic_timer_interrupt+0xa6/0xc0 [ 87.298947][ T5325] asm_sysvec_apic_timer_interrupt+0x1a/0x20 [ 87.301456][ T5325] [ 87.302426][ T5325] Last potentially related work creation: [ 87.304779][ T5325] kasan_save_stack+0x3e/0x60 [ 87.306790][ T5325] kasan_record_aux_stack+0xbd/0xd0 [ 87.309000][ T5325] kmem_cache_free+0x44f/0x650 [ 87.311048][ T5325] task_work_run+0x1d9/0x270 [ 87.312966][ T5325] exit_to_user_mode_loop+0x1fa/0x730 [ 87.315272][ T5325] do_syscall_64+0x353/0x580 [ 87.317281][ T5325] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 87.319777][ T5325] [ 87.320801][ T5325] Second to last potentially related work creation: [ 87.323560][ T5325] kasan_save_stack+0x3e/0x60 [ 87.326261][ T5325] kasan_record_aux_stack+0xbd/0xd0 [ 87.329020][ T5325] task_work_add+0xae/0x420 [ 87.330972][ T5325] __fput_deferred+0x143/0x380 [ 87.333011][ T5325] fput_close+0x11f/0x240 [ 87.334841][ T5325] filp_close+0x27/0x40 [ 87.336507][ T5325] gaudio_cleanup+0x54/0xf0 [ 87.338402][ T5325] f_audio_bind+0x4a0/0x630 [ 87.340386][ T5325] usb_add_function+0x2e1/0x9f0 [ 87.342591][ T5325] configfs_composite_bind+0xde0/0x1410 [ 87.345019][ T5325] gadget_bind_driver+0x2ca/0x9e0 [ 87.347226][ T5325] really_probe+0x254/0xae0 [ 87.349215][ T5325] __driver_probe_device+0x1e8/0x360 [ 87.351475][ T5325] driver_probe_device+0x4f/0x240 [ 87.353654][ T5325] __driver_attach+0x339/0x600 [ 87.355731][ T5325] bus_for_each_dev+0x23b/0x2c0 [ 87.357742][ T5325] bus_add_driver+0x345/0x670 [ 87.359672][ T5325] driver_register+0x23a/0x320 [ 87.361652][ T5325] usb_gadget_register_driver_owner+0xf9/0x270 [ 87.364066][ T5325] gadget_dev_desc_UDC_store+0x1c9/0x2f0 [ 87.366399][ T5325] configfs_write_iter+0x337/0x430 [ 87.368384][ T5325] vfs_write+0x612/0xba0 [ 87.370062][ T5325] ksys_write+0x150/0x270 [ 87.371931][ T5325] do_syscall_64+0x174/0x580 [ 87.373845][ T5325] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 87.375837][ T5325] [ 87.376749][ T5325] The buggy address belongs to the object at ffff8880122b58c0 [ 87.376749][ T5325] which belongs to the cache filp of size 352 [ 87.382353][ T5325] The buggy address is located 344 bytes inside of [ 87.382353][ T5325] freed 352-byte region [ffff8880122b58c0, ffff8880122b5a20) [ 87.388053][ T5325] [ 87.389103][ T5325] The buggy address belongs to the physical page: [ 87.391587][ T5325] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x122b5 [ 87.395114][ T5325] memcg:ffff88801fc57181 [ 87.396968][ T5325] flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) [ 87.399955][ T5325] page_type: f5(slab) [ 87.401681][ T5325] raw: 00fff00000000000 ffff888030414500 dead000000000100 dead000000000122 [ 87.405319][ T5325] raw: 0000000000000000 0000000800090009 00000000f5000000 ffff88801fc57181 [ 87.408827][ T5325] page dumped because: kasan: bad access detected [ 87.411482][ T5325] page_owner tracks the page as allocated [ 87.413803][ T5325] page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4702, tgid 4702 (udevd), ts 33161311862, free_ts 33131125770 [ 87.421886][ T5325] post_alloc_hook+0x1f9/0x250 [ 87.423913][ T5325] get_page_from_freelist+0x21fa/0x2270 [ 87.426255][ T5325] __alloc_frozen_pages_noprof+0x18d/0x380 [ 87.428714][ T5325] allocate_slab+0x79/0x5e0 [ 87.430680][ T5325] refill_objects+0x2d5/0x350 [ 87.432653][ T5325] __pcs_replace_empty_main+0x2bf/0x6b0 [ 87.434947][ T5325] kmem_cache_alloc_noprof+0x382/0x5f0 [ 87.437251][ T5325] alloc_empty_file+0x5b/0x1d0 [ 87.439291][ T5325] path_openat+0x8f/0x3830 [ 87.441287][ T5325] do_file_open+0x23e/0x4a0 [ 87.443309][ T5325] do_sys_openat2+0x115/0x200 [ 87.445374][ T5325] __x64_sys_openat+0x138/0x170 [ 87.447441][ T5325] do_syscall_64+0x174/0x580 [ 87.449360][ T5325] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 87.451829][ T5325] page last free pid 4710 tgid 4710 stack trace: [ 87.454493][ T5325] __free_frozen_pages+0xc1e/0xd10 [ 87.456662][ T5325] rcu_core+0x78b/0x10a0 [ 87.458559][ T5325] handle_softirqs+0x225/0x840 [ 87.460610][ T5325] __irq_exit_rcu+0xca/0x220 [ 87.462574][ T5325] irq_exit_rcu+0x9/0x30 [ 87.464336][ T5325] sysvec_apic_timer_interrupt+0xa6/0xc0 [ 87.466663][ T5325] asm_sysvec_apic_timer_interrupt+0x1a/0x20 [ 87.469191][ T5325] [ 87.470225][ T5325] Memory state around the buggy address: [ 87.472552][ T5325] ffff8880122b5900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 87.475852][ T5325] ffff8880122b5980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 87.479241][ T5325] >ffff8880122b5a00: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc [ 87.482647][ T5325] ^ [ 87.484636][ T5325] ffff8880122b5a80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 87.487932][ T5325] ffff8880122b5b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 87.491236][ T5325] ================================================================== [ 87.516590][ T5325] Kernel panic - not syncing: KASAN: panic_on_warn set ... [ 87.519710][ T5325] CPU: 0 UID: 0 PID: 5325 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) [ 87.523470][ T5325] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 87.527775][ T5325] Call Trace: [ 87.529257][ T5325] [ 87.530552][ T5325] vpanic+0x56c/0xa60 [ 87.532313][ T5325] ? __pfx_vpanic+0x10/0x10 [ 87.534317][ T5325] panic+0xc5/0xd0 [ 87.536023][ T5325] ? __pfx_panic+0x10/0x10 [ 87.537941][ T5325] ? preempt_schedule_thunk+0x16/0x40 [ 87.540209][ T5325] ? filp_flush+0x31/0x190 [ 87.542103][ T5325] ? preempt_schedule_thunk+0x16/0x40 [ 87.544217][ T5325] ? filp_flush+0x31/0x190 [ 87.546224][ T5325] check_panic_on_warn+0x89/0xb0 [ 87.548089][ T5325] ? filp_flush+0x31/0x190 [ 87.549935][ T5325] end_report+0x73/0x170 [ 87.551671][ T5325] ? filp_flush+0x31/0x190 [ 87.553432][ T5325] kasan_report+0x128/0x150 [ 87.555141][ T5325] ? filp_flush+0x31/0x190 [ 87.556769][ T5325] kasan_check_range+0x264/0x2c0 [ 87.558715][ T5325] filp_flush+0x31/0x190 [ 87.560383][ T5325] filp_close+0x1d/0x40 [ 87.561992][ T5325] gaudio_cleanup+0x54/0xf0 [ 87.563821][ T5325] f_audio_bind+0x4a0/0x630 [ 87.565684][ T5325] ? __pfx_f_audio_bind+0x10/0x10 [ 87.567650][ T5325] ? rcu_is_watching+0x15/0xb0 [ 87.569542][ T5325] ? usb_gadget_set_selfpowered+0xf5/0x260 [ 87.571652][ T5325] usb_add_function+0x2e1/0x9f0 [ 87.573371][ T5325] ? check_remote_wakeup_config+0x58/0x1c0 [ 87.575669][ T5325] configfs_composite_bind+0xde0/0x1410 [ 87.578086][ T5325] ? __pfx_configfs_composite_bind+0x10/0x10 [ 87.580773][ T5325] gadget_bind_driver+0x2ca/0x9e0 [ 87.582947][ T5325] ? __pfx_gadget_bind_driver+0x10/0x10 [ 87.585084][ T5325] really_probe+0x254/0xae0 [ 87.586938][ T5325] __driver_probe_device+0x1e8/0x360 [ 87.589095][ T5325] driver_probe_device+0x4f/0x240 [ 87.591159][ T5325] __driver_attach+0x339/0x600 [ 87.593096][ T5325] bus_for_each_dev+0x23b/0x2c0 [ 87.595004][ T5325] ? __pfx___driver_attach+0x10/0x10 [ 87.597084][ T5325] ? __pfx_bus_for_each_dev+0x10/0x10 [ 87.599330][ T5325] ? do_raw_spin_unlock+0x4d/0x210 [ 87.601502][ T5325] bus_add_driver+0x345/0x670 [ 87.603510][ T5325] driver_register+0x23a/0x320 [ 87.605619][ T5325] usb_gadget_register_driver_owner+0xf9/0x270 [ 87.608124][ T5325] gadget_dev_desc_UDC_store+0x1c9/0x2f0 [ 87.610482][ T5325] ? __pfx_gadget_dev_desc_UDC_store+0x10/0x10 [ 87.613087][ T5325] configfs_write_iter+0x337/0x430 [ 87.615304][ T5325] vfs_write+0x612/0xba0 [ 87.617051][ T5325] ? __pfx_vfs_write+0x10/0x10 [ 87.619081][ T5325] ? __fget_files+0x2a/0x420 [ 87.621090][ T5325] ksys_write+0x150/0x270 [ 87.622972][ T5325] ? __pfx_ksys_write+0x10/0x10 [ 87.624995][ T5325] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 87.627534][ T5325] do_syscall_64+0x174/0x580 [ 87.629448][ T5325] ? trace_irq_disable+0x3b/0x140 [ 87.631544][ T5325] ? clear_bhb_loop+0x40/0x90 [ 87.633469][ T5325] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 87.635994][ T5325] RIP: 0033:0x7f94a6d9e019 [ 87.637841][ T5325] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 [ 87.646427][ T5325] RSP: 002b:00007f94a7d1bfe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 87.650464][ T5325] RAX: ffffffffffffffda RBX: 00007f94a7026090 RCX: 00007f94a6d9e019 [ 87.654339][ T5325] RDX: 000000000000000c RSI: 0000200000000400 RDI: 0000000000000004 [ 87.657692][ T5325] RBP: 00007f94a6e3500c R08: 0000000000000000 R09: 0000000000000000 [ 87.660806][ T5325] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 87.664030][ T5325] R13: 00007f94a7026128 R14: 00007f94a7026090 R15: 00007fff4f9549e8 [ 87.667220][ T5325] [ 87.668860][ T5325] Kernel Offset: disabled [ 87.670606][ T5325] Rebooting in 86400 seconds..