================================================================== BUG: KASAN: slab-use-after-free in find_endpoint+0x2a3/0x2c0 drivers/usb/gadget/udc/dummy_hcd.c:1618 Read of size 1 at addr ffff888057e2a912 by task kworker/0:6/24726 CPU: 0 UID: 0 PID: 24726 Comm: kworker/0:6 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026 Workqueue: usb_hub_wq hub_event Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x13d/0x4b0 mm/kasan/report.c:482 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595 find_endpoint+0x2a3/0x2c0 drivers/usb/gadget/udc/dummy_hcd.c:1618 dummy_timer+0x500/0x3700 drivers/usb/gadget/udc/dummy_hcd.c:1890 __run_hrtimer kernel/time/hrtimer.c:2067 [inline] __hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2124 hrtimer_run_softirq+0x1ca/0x360 kernel/time/hrtimer.c:2141 handle_softirqs+0x1e6/0x9d0 kernel/softirq.c:645 __do_softirq kernel/softirq.c:679 [inline] invoke_softirq kernel/softirq.c:519 [inline] __irq_exit_rcu+0x194/0x210 kernel/softirq.c:767 irq_exit_rcu+0x9/0x30 kernel/softirq.c:784 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:211 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:221 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 26 dd 14 f6 48 89 df e8 4e 33 15 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 25 3a 04 f6 65 48 83 3d e4 a4 b9 08 00 74 16 5b RSP: 0018:ffffc9000660ef18 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffff888079da8108 RCX: 0000000000000040 RDX: 0000000000000001 RSI: ffffffff8e3eb021 RDI: ffffffff8c620e80 RBP: 0000000000000287 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000287 R13: ffff888079da8028 R14: ffff888079da8108 R15: ffff8880335cb100 spin_unlock_irqrestore include/linux/spinlock.h:425 [inline] class_spinlock_irqsave_destructor include/linux/spinlock.h:642 [inline] xpad_inquiry_pad_presence drivers/input/joystick/xpad.c:1456 [inline] xpad360w_start_input+0x394/0x4b0 drivers/input/joystick/xpad.c:1862 xpad_probe+0x178e/0x1f60 drivers/input/joystick/xpad.c:2194 usb_probe_interface+0x386/0x9b0 drivers/usb/core/driver.c:399 call_driver_probe drivers/base/dd.c:628 [inline] really_probe+0x241/0xa60 drivers/base/dd.c:706 __driver_probe_device+0x210/0x460 drivers/base/dd.c:868 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153 bus_probe_device+0x64/0x160 drivers/base/bus.c:620 device_add+0x121d/0x1970 drivers/base/core.c:3776 usb_set_configuration+0xd97/0x1c60 drivers/usb/core/message.c:2268 usb_generic_driver_probe+0xa1/0xe0 drivers/usb/core/generic.c:250 usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:293 call_driver_probe drivers/base/dd.c:628 [inline] really_probe+0x241/0xa60 drivers/base/dd.c:706 __driver_probe_device+0x210/0x460 drivers/base/dd.c:868 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153 bus_probe_device+0x64/0x160 drivers/base/bus.c:620 device_add+0x121d/0x1970 drivers/base/core.c:3776 usb_new_device.part.0+0xcc2/0x1686 drivers/usb/core/hub.c:2708 usb_new_device include/linux/workqueue.h:715 [inline] hub_port_connect drivers/usb/core/hub.c:5580 [inline] hub_port_connect_change drivers/usb/core/hub.c:5720 [inline] port_event drivers/usb/core/hub.c:5884 [inline] hub_event.cold+0x1e3/0xe90 drivers/usb/core/hub.c:5966 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396 process_scheduled_works kernel/workqueue.c:3479 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 27639: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x2f8/0x6d0 mm/slub.c:5563 _kmalloc_noprof include/linux/slab.h:991 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] genradix_alloc_node include/linux/generic-radix-tree.h:101 [inline] __genradix_ptr_alloc+0x4e3/0x610 lib/generic-radix-tree.c:69 __genradix_prealloc+0x5c/0x90 lib/generic-radix-tree.c:216 sctp_stream_alloc_out net/sctp/stream.c:113 [inline] sctp_send_add_streams+0x423/0x580 net/sctp/stream.c:468 sctp_setsockopt_add_streams net/sctp/socket.c:4157 [inline] sctp_setsockopt+0x4a6e/0xb370 net/sctp/socket.c:4753 do_sock_setsockopt+0xf3/0x1d0 net/socket.c:2397 __sys_setsockopt+0x195/0x220 net/socket.c:2422 __do_sys_setsockopt net/socket.c:2428 [inline] __se_sys_setsockopt net/socket.c:2425 [inline] __x64_sys_setsockopt+0xbd/0x160 net/socket.c:2425 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 27636: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2748 [inline] slab_free mm/slub.c:6499 [inline] kfree+0x22b/0x6d0 mm/slub.c:6792 genradix_free_node include/linux/generic-radix-tree.h:106 [inline] genradix_free_recurse lib/generic-radix-tree.c:207 [inline] genradix_free_recurse+0x668/0x890 lib/generic-radix-tree.c:204 genradix_free_recurse lib/generic-radix-tree.c:204 [inline] __genradix_free+0x97/0x110 lib/generic-radix-tree.c:227 sctp_stream_free+0xd5/0x120 net/sctp/stream.c:200 sctp_association_free+0x241/0x7d0 net/sctp/associola.c:351 sctp_cmd_delete_tcb net/sctp/sm_sideeffect.c:950 [inline] sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1340 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1204 [inline] sctp_do_sm+0x15b5/0x5c90 net/sctp/sm_sideeffect.c:1175 sctp_primitive_ABORT+0x9f/0xd0 net/sctp/primitive.c:104 sctp_close+0x232/0x980 net/sctp/socket.c:1527 inet_release+0xed/0x200 net/ipv4/af_inet.c:442 inet6_release+0x4f/0x70 net/ipv6/af_inet6.c:472 __sock_release+0xb3/0x260 net/socket.c:735 sock_close+0x1c/0x30 net/socket.c:1526 __fput+0x3ff/0xb50 fs/file_table.c:512 task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:70 [inline] exit_to_user_mode_loop+0x1d8/0x700 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline] do_syscall_64+0x661/0x790 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888057e2a800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 274 bytes inside of freed 512-byte region [ffff888057e2a800, ffff888057e2aa00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x57e28 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801c02ec80 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801c02ec80 dead000000000100 dead000000000122 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffffffffffff01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6062, tgid 6057 (syz.3.64), ts 111335797335 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1871 prep_new_page mm/page_alloc.c:1879 [inline] get_page_from_freelist+0x110d/0x35d0 mm/page_alloc.c:3943 __alloc_frozen_pages_noprof+0x2eb/0x3300 mm/page_alloc.c:5436 alloc_slab_page mm/slub.c:3347 [inline] allocate_slab mm/slub.c:3462 [inline] new_slab+0xa9/0x6e0 mm/slub.c:3513 refill_objects+0xe3/0x410 mm/slub.c:7410 refill_sheaf mm/slub.c:2885 [inline] __pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4774 alloc_from_pcs mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:4984 [inline] __kmalloc_cache_noprof+0x4f4/0x6d0 mm/slub.c:5559 _kmalloc_noprof include/linux/slab.h:991 [inline] snd_mixer_oss_build_test+0x7a/0x380 sound/core/oss/mixer_oss.c:893 snd_mixer_oss_build_test_all+0x33c/0x6e0 sound/core/oss/mixer_oss.c:963 snd_mixer_oss_build_input+0x139/0xd50 sound/core/oss/mixer_oss.c:1017 snd_mixer_oss_build sound/core/oss/mixer_oss.c:1276 [inline] snd_mixer_oss_notify_handler+0x48d/0x990 sound/core/oss/mixer_oss.c:1344 snd_card_register+0x2af/0x760 sound/core/init.c:935 f_midi2_create_card drivers/usb/gadget/function/f_midi2.c:1616 [inline] f_midi2_bind+0x1198/0x2770 drivers/usb/gadget/function/f_midi2.c:1948 usb_add_function+0x219/0x890 drivers/usb/gadget/composite.c:333 configfs_composite_bind+0xd83/0x1960 drivers/usb/gadget/configfs.c:1802 gadget_bind_driver+0x28c/0xbf0 drivers/usb/gadget/udc/core.c:1662 page last free pid 5943 tgid 5943 ts 93901426805 stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] __free_frozen_pages+0x79f/0x10f0 mm/page_alloc.c:2962 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4683 [inline] slab_alloc_node mm/slub.c:4996 [inline] kmem_cache_alloc_noprof+0x269/0x6a0 mm/slub.c:5010 ptlock_alloc+0x1f/0x70 mm/memory.c:7721 ptlock_init include/linux/mm.h:3884 [inline] pagetable_pte_ctor include/linux/mm.h:3933 [inline] __pte_alloc_one_noprof include/asm-generic/pgalloc.h:79 [inline] pte_alloc_one+0x82/0x3d0 arch/x86/mm/pgtable.c:18 do_fault_around mm/memory.c:5952 [inline] do_read_fault mm/memory.c:5991 [inline] do_fault+0x960/0x1830 mm/memory.c:6134 do_pte_missing mm/memory.c:4700 [inline] handle_pte_fault mm/memory.c:6558 [inline] __handle_mm_fault+0x150b/0x2f60 mm/memory.c:6707 handle_mm_fault+0x363/0xa20 mm/memory.c:6876 do_user_addr_fault+0x59c/0x12f0 arch/x86/mm/fault.c:1343 handle_page_fault arch/x86/mm/fault.c:1483 [inline] exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 Memory state around the buggy address: ffff888057e2a800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888057e2a880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888057e2a900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888057e2a980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888057e2aa00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: f5 cmc 1: 53 push %rbx 2: 48 8b 74 24 10 mov 0x10(%rsp),%rsi 7: 48 89 fb mov %rdi,%rbx a: 48 83 c7 18 add $0x18,%rdi e: e8 26 dd 14 f6 call 0xf614dd39 13: 48 89 df mov %rbx,%rdi 16: e8 4e 33 15 f6 call 0xf6153369 1b: f7 c5 00 02 00 00 test $0x200,%ebp 21: 75 23 jne 0x46 23: 9c pushf 24: 58 pop %rax 25: f6 c4 02 test $0x2,%ah 28: 75 37 jne 0x61 * 2a: bf 01 00 00 00 mov $0x1,%edi <-- trapping instruction 2f: e8 25 3a 04 f6 call 0xf6043a59 34: 65 48 83 3d e4 a4 b9 cmpq $0x0,%gs:0x8b9a4e4(%rip) # 0x8b9a521 3b: 08 00 3d: 74 16 je 0x55 3f: 5b pop %rbx