================================================================== BUG: KASAN: use-after-free in kobject_get+0x113/0x120 lib/kobject.c:663 Read of size 1 at addr ffff8881261e083c by task syz.0.255/1398 CPU: 0 PID: 1398 Comm: syz.0.255 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0x100/0x140 mm/kasan/report.c:452 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:306 kobject_get+0x113/0x120 lib/kobject.c:663 get_device drivers/base/core.c:3361 [inline] device_add+0x331/0xc00 drivers/base/core.c:3191 device_create_groups_vargs drivers/base/core.c:3960 [inline] device_create+0x26c/0x300 drivers/base/core.c:4002 create_function_device+0x60/0x70 drivers/usb/gadget/configfs.c:31 create_alsa_device drivers/usb/gadget/function/f_midi.c:1262 [inline] f_midi_alloc_inst+0x1a8/0x380 drivers/usb/gadget/function/f_midi.c:1303 try_get_usb_function_instance drivers/usb/gadget/functions.c:28 [inline] usb_get_function_instance+0xe2/0x2f0 drivers/usb/gadget/functions.c:44 function_make+0x118/0x350 drivers/usb/gadget/configfs.c:636 configfs_mkdir+0x5d2/0xd90 fs/configfs/dir.c:1382 vfs_mkdir+0x42c/0x600 fs/namei.c:3840 do_mkdirat+0x14c/0x340 fs/namei.c:3862 __do_sys_mkdirat fs/namei.c:3873 [inline] __se_sys_mkdirat fs/namei.c:3871 [inline] __x64_sys_mkdirat+0x7b/0x90 fs/namei.c:3871 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fef95320159 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 RSP: 002b:00007fef93d79028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fef955a7fa0 RCX: 00007fef95320159 RDX: 00000000000001ff RSI: 0000200000000100 RDI: ffffffffffffff9c RBP: 00007fef953b706b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fef955a8038 R14: 00007fef955a7fa0 R15: 00007ffd360784c8 Allocated by task 870: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:430 [inline] ____kasan_kmalloc mm/kasan/common.c:509 [inline] __kasan_kmalloc+0xd4/0x100 mm/kasan/common.c:518 kasan_kmalloc include/linux/kasan.h:254 [inline] kmem_cache_alloc_trace+0x179/0x2e0 mm/slub.c:2979 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:667 [inline] device_create_groups_vargs drivers/base/core.c:3942 [inline] device_create+0x13a/0x300 drivers/base/core.c:4002 android_device_create drivers/usb/gadget/configfs.c:1789 [inline] gadgets_make+0x816/0xa70 drivers/usb/gadget/configfs.c:1886 configfs_mkdir+0x5d2/0xd90 fs/configfs/dir.c:1382 vfs_mkdir+0x42c/0x600 fs/namei.c:3840 do_mkdirat+0x14c/0x340 fs/namei.c:3862 __do_sys_mkdirat fs/namei.c:3873 [inline] __se_sys_mkdirat fs/namei.c:3871 [inline] __x64_sys_mkdirat+0x7b/0x90 fs/namei.c:3871 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358 kvfree_call_rcu+0x117/0x670 kernel/rcu/tree.c:3539 drop_sysctl_table+0x2f5/0x430 fs/proc/proc_sysctl.c:1684 unregister_sysctl_table+0x75/0x120 fs/proc/proc_sysctl.c:1722 unregister_net_sysctl_table+0x15/0x20 net/sysctl_net.c:127 neigh_sysctl_unregister+0x78/0x90 net/core/neighbour.c:3732 addrconf_sysctl_unregister net/ipv6/addrconf.c:7138 [inline] addrconf_ifdown+0x1628/0x1890 net/ipv6/addrconf.c:3946 addrconf_notify+0x3bd/0xea0 net/ipv6/addrconf.c:-1 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0x90/0x100 kernel/notifier.c:410 call_netdevice_notifiers_info net/core/dev.c:2052 [inline] call_netdevice_notifiers_extack net/core/dev.c:2064 [inline] call_netdevice_notifiers net/core/dev.c:2078 [inline] unregister_netdevice_many+0x100e/0x19f0 net/core/dev.c:10778 unregister_netdevice_queue+0x2e1/0x320 net/core/dev.c:10712 unregister_netdevice include/linux/netdevice.h:2939 [inline] __tun_detach+0xc9d/0x1450 drivers/net/tun.c:697 tun_detach drivers/net/tun.c:713 [inline] tun_chr_close+0x92/0x140 drivers/net/tun.c:3489 __fput+0x2dc/0x730 fs/file_table.c:281 ____fput+0x15/0x20 fs/file_table.c:314 task_work_run+0x127/0x190 kernel/task_work.c:189 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0xa7c/0x24e0 kernel/exit.c:879 do_group_exit+0x149/0x310 kernel/exit.c:993 __do_sys_exit_group kernel/exit.c:1004 [inline] __se_sys_exit_group kernel/exit.c:1002 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1002 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff8881261e0800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 60 bytes inside of 1024-byte region [ffff8881261e0800, ffff8881261e0c00) The buggy address belongs to the page: page:ffffea0004987800 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8881261e0800 pfn:0x1261e0 head:ffffea0004987800 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 ffffea00044c9608 ffff888100040b10 ffff888100042f00 raw: ffff8881261e0800 000000000010000d 00000001ffffffff 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 279, ts 22930142378, free_ts 0 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x176/0x190 mm/page_alloc.c:2462 get_page_from_freelist+0x225f/0x23f0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x29a/0x640 mm/page_alloc.c:5384 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1813 [inline] new_slab+0x84/0x3f0 mm/slub.c:1874 new_slab_objects mm/slub.c:2632 [inline] ___slab_alloc+0x2f8/0x4c0 mm/slub.c:2796 __slab_alloc+0x63/0xa0 mm/slub.c:2836 slab_alloc_node mm/slub.c:2918 [inline] slab_alloc mm/slub.c:2960 [inline] __kmalloc+0x1f9/0x330 mm/slub.c:4034 kmalloc include/linux/slab.h:560 [inline] kzalloc include/linux/slab.h:667 [inline] __register_sysctl_table+0xeb/0x1240 fs/proc/proc_sysctl.c:1323 register_net_sysctl+0x2c/0x40 net/sysctl_net.c:121 neigh_sysctl_register+0x9a9/0xa90 net/core/neighbour.c:3713 devinet_sysctl_register+0xaf/0x1e0 net/ipv4/devinet.c:2635 inetdev_init+0x26c/0x490 net/ipv4/devinet.c:277 inetdev_event+0x1f4/0x1010 net/ipv4/devinet.c:1544 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0x90/0x100 kernel/notifier.c:410 call_netdevice_notifiers_info net/core/dev.c:2052 [inline] call_netdevice_notifiers_extack net/core/dev.c:2064 [inline] call_netdevice_notifiers+0x119/0x190 net/core/dev.c:2078 register_netdevice+0x100a/0x13a0 net/core/dev.c:10098 page_owner free stack trace missing Memory state around the buggy address: ffff8881261e0700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8881261e0780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8881261e0800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881261e0880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881261e0900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== general protection fault, probably for non-canonical address 0xe70722662a840b6f: 0000 [#1] PREEMPT SMP KASAN KASAN: maybe wild-memory-access in range [0x3839333154205b78-0x3839333154205b7f] CPU: 0 PID: 1398 Comm: syz.0.255 Tainted: G B syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:kobj_child_ns_ops lib/kobject.c:1084 [inline] RIP: 0010:kobj_ns_ops lib/kobject.c:1092 [inline] RIP: 0010:kobject_namespace lib/kobject.c:30 [inline] RIP: 0010:create_dir lib/kobject.c:89 [inline] RIP: 0010:kobject_add_internal+0x5e3/0xde0 lib/kobject.c:263 Code: 4c 89 e7 e8 af 1e 45 ff 4d 8b 24 24 4d 85 e4 0f 84 db 00 00 00 49 83 c4 20 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 e7 e8 7f 1e 45 ff 49 8b 04 24 48 85 c0 0f RSP: 0018:ffffc9000132f7d8 EFLAGS: 00010207 RAX: 070726662a840b6f RBX: ffff8881069d1500 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff8881261e0828 RBP: ffffc9000132f830 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000265eec R12: 3839333154205b7d R13: ffff8881069d1518 R14: ffffffff8681cea0 R15: ffff8881261e0800 FS: 00007fef93d796c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fef93d58d58 CR3: 000000010f6f8000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kobject_add_varg lib/kobject.c:398 [inline] kobject_add+0x165/0x230 lib/kobject.c:450 class_dir_create_and_add drivers/base/core.c:2825 [inline] get_device_parent+0x3a6/0x410 drivers/base/core.c:2880 device_add+0x349/0xc00 drivers/base/core.c:3192 device_create_groups_vargs drivers/base/core.c:3960 [inline] device_create+0x26c/0x300 drivers/base/core.c:4002 create_function_device+0x60/0x70 drivers/usb/gadget/configfs.c:31 create_alsa_device drivers/usb/gadget/function/f_midi.c:1262 [inline] f_midi_alloc_inst+0x1a8/0x380 drivers/usb/gadget/function/f_midi.c:1303 try_get_usb_function_instance drivers/usb/gadget/functions.c:28 [inline] usb_get_function_instance+0xe2/0x2f0 drivers/usb/gadget/functions.c:44 function_make+0x118/0x350 drivers/usb/gadget/configfs.c:636 configfs_mkdir+0x5d2/0xd90 fs/configfs/dir.c:1382 vfs_mkdir+0x42c/0x600 fs/namei.c:3840 do_mkdirat+0x14c/0x340 fs/namei.c:3862 __do_sys_mkdirat fs/namei.c:3873 [inline] __se_sys_mkdirat fs/namei.c:3871 [inline] __x64_sys_mkdirat+0x7b/0x90 fs/namei.c:3871 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fef95320159 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 RSP: 002b:00007fef93d79028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fef955a7fa0 RCX: 00007fef95320159 RDX: 00000000000001ff RSI: 0000200000000100 RDI: ffffffffffffff9c RBP: 00007fef953b706b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fef955a8038 R14: 00007fef955a7fa0 R15: 00007ffd360784c8 Modules linked in: ---[ end trace 40dc4af43541ed6e ]--- RIP: 0010:kobj_child_ns_ops lib/kobject.c:1084 [inline] RIP: 0010:kobj_ns_ops lib/kobject.c:1092 [inline] RIP: 0010:kobject_namespace lib/kobject.c:30 [inline] RIP: 0010:create_dir lib/kobject.c:89 [inline] RIP: 0010:kobject_add_internal+0x5e3/0xde0 lib/kobject.c:263 Code: 4c 89 e7 e8 af 1e 45 ff 4d 8b 24 24 4d 85 e4 0f 84 db 00 00 00 49 83 c4 20 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 e7 e8 7f 1e 45 ff 49 8b 04 24 48 85 c0 0f RSP: 0018:ffffc9000132f7d8 EFLAGS: 00010207 RAX: 070726662a840b6f RBX: ffff8881069d1500 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff8881261e0828 RBP: ffffc9000132f830 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000265eec R12: 3839333154205b7d R13: ffff8881069d1518 R14: ffffffff8681cea0 R15: ffff8881261e0800 FS: 00007fef93d796c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fef93d57ff8 CR3: 000000010f6f8000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 4c 89 e7 mov %r12,%rdi 3: e8 af 1e 45 ff call 0xff451eb7 8: 4d 8b 24 24 mov (%r12),%r12 c: 4d 85 e4 test %r12,%r12 f: 0f 84 db 00 00 00 je 0xf0 15: 49 83 c4 20 add $0x20,%r12 19: 4c 89 e0 mov %r12,%rax 1c: 48 c1 e8 03 shr $0x3,%rax 20: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx 27: fc ff df * 2a: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) <-- trapping instruction 2e: 74 08 je 0x38 30: 4c 89 e7 mov %r12,%rdi 33: e8 7f 1e 45 ff call 0xff451eb7 38: 49 8b 04 24 mov (%r12),%rax 3c: 48 85 c0 test %rax,%rax 3f: 0f .byte 0xf