================================================================== BUG: KASAN: slab-out-of-bounds in kobject_get+0x113/0x120 lib/kobject.c:663 Read of size 1 at addr ffff88810f96483c by task syz.7.2655/9167 CPU: 0 PID: 9167 Comm: syz.7.2655 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:3798 do_mkdirat+0x14c/0x340 fs/namei.c:3820 __do_sys_mkdirat fs/namei.c:3831 [inline] __se_sys_mkdirat fs/namei.c:3829 [inline] __x64_sys_mkdirat+0x7b/0x90 fs/namei.c:3829 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f9b8e7f50d9 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:00007f9b8d24e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f9b8ea7cfa0 RCX: 00007f9b8e7f50d9 RDX: 00000000000001ff RSI: 0000200000000100 RDI: ffffffffffffff9c RBP: 00007f9b8e88c024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9b8ea7d038 R14: 00007f9b8ea7cfa0 R15: 00007ffc13f9ab08 Allocated by task 0: (stack is not available) The buggy address belongs to the object at ffff88810f964000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 60 bytes to the right of 2048-byte region [ffff88810f964000, ffff88810f964800) The buggy address belongs to the page: page:ffffea00043e5800 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88810f967000 pfn:0x10f960 head:ffffea00043e5800 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 ffffea000469e008 ffffea0004dbe808 ffff888100042d80 raw: ffff88810f967000 0000000000080007 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5150, ts 163676078920, free_ts 163668881094 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_array include/linux/slab.h:595 [inline] kcalloc include/linux/slab.h:606 [inline] veth_alloc_queues drivers/net/veth.c:1029 [inline] veth_dev_init+0x1bc/0x360 drivers/net/veth.c:1056 register_netdevice+0x328/0x13a0 net/core/dev.c:9997 veth_newlink+0x854/0xb60 drivers/net/veth.c:1387 __rtnl_newlink net/core/rtnetlink.c:3494 [inline] rtnl_newlink+0x1307/0x1830 net/core/rtnetlink.c:3542 rtnetlink_rcv_msg+0x9e9/0xca0 net/core/rtnetlink.c:5622 netlink_rcv_skb+0x1e9/0x430 net/netlink/af_netlink.c:2508 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5640 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x86c/0xa30 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x949/0xb70 net/netlink/af_netlink.c:1919 page last free stack trace: reset_page_owner include/linux/page_owner.h:28 [inline] free_pages_prepare mm/page_alloc.c:1349 [inline] __free_pages_ok+0x80b/0x830 mm/page_alloc.c:1629 free_the_page mm/page_alloc.c:5445 [inline] __free_pages+0xd8/0x390 mm/page_alloc.c:5454 __free_slab+0xcf/0x190 mm/slub.c:1899 free_slab mm/slub.c:1914 [inline] discard_slab mm/slub.c:1920 [inline] unfreeze_partials+0x150/0x180 mm/slub.c:2415 put_cpu_partial+0xc1/0x180 mm/slub.c:2451 __slab_free+0x2c9/0x3a0 mm/slub.c:3100 do_slab_free mm/slub.c:3196 [inline] ___cache_free+0x10e/0x130 mm/slub.c:3215 qlink_free+0x50/0x90 mm/kasan/quarantine.c:157 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x14a/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xe0 mm/kasan/common.c:440 kasan_slab_alloc include/linux/kasan.h:244 [inline] slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:580 slab_alloc_node mm/slub.c:2952 [inline] slab_alloc mm/slub.c:2960 [inline] kmem_cache_alloc_trace+0x155/0x2e0 mm/slub.c:2977 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:667 [inline] kset_create lib/kobject.c:982 [inline] kset_create_and_add+0x59/0x2c0 lib/kobject.c:1025 register_queue_kobjects net/core/net-sysfs.c:1742 [inline] netdev_register_kobject+0x1be/0x330 net/core/net-sysfs.c:2001 register_netdevice+0xdae/0x13a0 net/core/dev.c:10067 Memory state around the buggy address: ffff88810f964700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88810f964780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88810f964800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88810f964880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88810f964900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ------------[ cut here ]------------ kobject: '(null)' (ffff88810f964800): is not initialized, yet kobject_get() is being called. WARNING: CPU: 0 PID: 9167 at lib/kobject.c:666 kobject_get+0x7c/0x120 lib/kobject.c:664 Modules linked in: CPU: 0 PID: 9167 Comm: syz.7.2655 Tainted: G B syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:kobject_get+0x7c/0x120 lib/kobject.c:664 Code: 0a ff 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 06 47 45 ff 48 8b 33 48 c7 c7 40 9f 41 85 48 89 da e8 54 29 1f 02 <0f> 0b eb 0c e8 9b d1 0a ff eb 4c e8 94 d1 0a ff 4c 8d 73 38 4c 89 RSP: 0018:ffffc90000ed7970 EFLAGS: 00010246 RAX: f93088cd98b5fd00 RBX: ffff88810f964800 RCX: 0000000000080000 RDX: ffffc9000f23d000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc90000ed7988 R08: ffff8881f7052fbf R09: 1ffff1103ee0a5f7 R10: dffffc0000000000 R11: ffffed103ee0a5f8 R12: 0000000000000000 R13: ffff8881106f2068 R14: 0000000000000000 R15: dffffc0000000000 FS: 00007f9b8d24e6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2f24bd CR3: 00000001359a7000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: 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:3798 do_mkdirat+0x14c/0x340 fs/namei.c:3820 __do_sys_mkdirat fs/namei.c:3831 [inline] __se_sys_mkdirat fs/namei.c:3829 [inline] __x64_sys_mkdirat+0x7b/0x90 fs/namei.c:3829 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f9b8e7f50d9 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:00007f9b8d24e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f9b8ea7cfa0 RCX: 00007f9b8e7f50d9 RDX: 00000000000001ff RSI: 0000200000000100 RDI: ffffffffffffff9c RBP: 00007f9b8e88c024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9b8ea7d038 R14: 00007f9b8ea7cfa0 R15: 00007ffc13f9ab08 ---[ end trace 88c069e38727e25d ]--- ------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 0 PID: 9167 at lib/refcount.c:25 refcount_warn_saturate+0x104/0x1a0 lib/refcount.c:25 Modules linked in: CPU: 0 PID: 9167 Comm: syz.7.2655 Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:refcount_warn_saturate+0x104/0x1a0 lib/refcount.c:25 Code: 04 01 48 c7 c7 40 4d 40 85 e8 38 fd 3a 02 0f 0b eb df e8 7f a5 26 ff c6 05 7c 92 82 04 01 48 c7 c7 80 4c 40 85 e8 1c fd 3a 02 <0f> 0b eb c3 e8 63 a5 26 ff c6 05 61 92 82 04 01 48 c7 c7 e0 4c 40 RSP: 0018:ffffc90000ed7950 EFLAGS: 00010246 RAX: f93088cd98b5fd00 RBX: 0000000000000002 RCX: 0000000000080000 RDX: ffffc9000f23d000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc90000ed7960 R08: ffff8881f7052fbf R09: 1ffff1103ee0a5f7 R10: dffffc0000000000 R11: ffffed103ee0a5f8 R12: 0000000000000000 R13: ffff8881106f2068 R14: 0000000000000002 R15: 0000000000000000 FS: 00007f9b8d24e6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2f24bd CR3: 00000001359a7000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_add include/linux/refcount.h:-1 [inline] __refcount_inc include/linux/refcount.h:250 [inline] refcount_inc include/linux/refcount.h:267 [inline] kref_get include/linux/kref.h:45 [inline] kobject_get+0xfb/0x120 lib/kobject.c:667 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:3798 do_mkdirat+0x14c/0x340 fs/namei.c:3820 __do_sys_mkdirat fs/namei.c:3831 [inline] __se_sys_mkdirat fs/namei.c:3829 [inline] __x64_sys_mkdirat+0x7b/0x90 fs/namei.c:3829 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f9b8e7f50d9 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:00007f9b8d24e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f9b8ea7cfa0 RCX: 00007f9b8e7f50d9 RDX: 00000000000001ff RSI: 0000200000000100 RDI: ffffffffffffff9c RBP: 00007f9b8e88c024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9b8ea7d038 R14: 00007f9b8ea7cfa0 R15: 00007ffc13f9ab08 ---[ end trace 88c069e38727e25e ]--- ------------[ cut here ]------------ kobject: '(null)' (ffff88810f964800): is not initialized, yet kobject_get() is being called. WARNING: CPU: 0 PID: 9167 at lib/kobject.c:666 kobject_get lib/kobject.c:664 [inline] WARNING: CPU: 0 PID: 9167 at lib/kobject.c:666 kobject_add_internal+0x12e/0xde0 lib/kobject.c:248 Modules linked in: CPU: 0 PID: 9167 Comm: syz.7.2655 Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:kobject_get lib/kobject.c:664 [inline] RIP: 0010:kobject_add_internal+0x12e/0xde0 lib/kobject.c:248 Code: b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 4c 89 e7 e8 85 2e 45 ff 49 8b 34 24 48 c7 c7 40 9f 41 85 4c 89 e2 e8 d2 10 1f 02 <0f> 0b e9 04 01 00 00 e8 16 b9 0a ff b8 fe ff ff ff e9 b0 09 00 00 RSP: 0018:ffffc90000ed77d8 EFLAGS: 00010246 RAX: f93088cd98b5fd00 RBX: ffff88810bb9c400 RCX: 0000000000080000 RDX: ffffc9000f23d000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc90000ed7830 R08: ffff8881f7052fbf R09: 1ffff1103ee0a5f7 R10: dffffc0000000000 R11: ffffed103ee0a5f8 R12: ffff88810f964800 R13: ffff88810bb9c418 R14: 0000000000000000 R15: 1ffff11021773880 FS: 00007f9b8d24e6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2f24bd CR3: 00000001359a7000 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:3798 do_mkdirat+0x14c/0x340 fs/namei.c:3820 __do_sys_mkdirat fs/namei.c:3831 [inline] __se_sys_mkdirat fs/namei.c:3829 [inline] __x64_sys_mkdirat+0x7b/0x90 fs/namei.c:3829 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f9b8e7f50d9 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:00007f9b8d24e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f9b8ea7cfa0 RCX: 00007f9b8e7f50d9 RDX: 00000000000001ff RSI: 0000200000000100 RDI: ffffffffffffff9c RBP: 00007f9b8e88c024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9b8ea7d038 R14: 00007f9b8ea7cfa0 R15: 00007ffc13f9ab08 ---[ end trace 88c069e38727e25f ]--- ------------[ cut here ]------------ refcount_t: saturated; leaking memory. WARNING: CPU: 0 PID: 9167 at lib/refcount.c:22 refcount_warn_saturate+0x158/0x1a0 lib/refcount.c:22 Modules linked in: CPU: 0 PID: 9167 Comm: syz.7.2655 Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:refcount_warn_saturate+0x158/0x1a0 lib/refcount.c:22 Code: 04 01 48 c7 c7 00 4c 40 85 e8 e4 fc 3a 02 0f 0b eb 8b e8 2b a5 26 ff c6 05 27 92 82 04 01 48 c7 c7 00 4c 40 85 e8 c8 fc 3a 02 <0f> 0b e9 6c ff ff ff e8 0c a5 26 ff c6 05 0c 92 82 04 01 48 c7 c7 RSP: 0018:ffffc90000ed77b8 EFLAGS: 00010246 RAX: f93088cd98b5fd00 RBX: 0000000000000001 RCX: 0000000000080000 RDX: ffffc9000f23d000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc90000ed77c8 R08: ffff8881f7052fbf R09: 1ffff1103ee0a5f7 R10: dffffc0000000000 R11: ffffed103ee0a5f8 R12: 00000000c0000000 R13: ffff88810bb9c418 R14: 0000000000000001 R15: ffff88810f964838 FS: 00007f9b8d24e6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2f24bd CR3: 00000001359a7000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_add include/linux/refcount.h:-1 [inline] __refcount_inc include/linux/refcount.h:250 [inline] refcount_inc include/linux/refcount.h:267 [inline] kref_get include/linux/kref.h:45 [inline] kobject_get lib/kobject.c:667 [inline] kobject_add_internal+0xc44/0xde0 lib/kobject.c:248 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:3798 do_mkdirat+0x14c/0x340 fs/namei.c:3820 __do_sys_mkdirat fs/namei.c:3831 [inline] __se_sys_mkdirat fs/namei.c:3829 [inline] __x64_sys_mkdirat+0x7b/0x90 fs/namei.c:3829 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f9b8e7f50d9 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:00007f9b8d24e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f9b8ea7cfa0 RCX: 00007f9b8e7f50d9 RDX: 00000000000001ff RSI: 0000200000000100 RDI: ffffffffffffff9c RBP: 00007f9b8e88c024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9b8ea7d038 R14: 00007f9b8ea7cfa0 R15: 00007ffc13f9ab08 ---[ end trace 88c069e38727e260 ]--- ------------[ cut here ]------------ kobject: '(null)' (ffff88810f964800): is not initialized, yet kobject_put() is being called. WARNING: CPU: 0 PID: 9167 at lib/kobject.c:760 kobject_put+0x8a/0x270 lib/kobject.c:758 Modules linked in: CPU: 0 PID: 9167 Comm: syz.7.2655 Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:kobject_put+0x8a/0x270 lib/kobject.c:758 Code: 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 d8 45 45 ff 48 8b 33 48 c7 c7 c0 9f 41 85 48 89 da e8 26 28 1f 02 <0f> 0b eb 0f e8 6d d0 0a ff e9 7c 01 00 00 e8 63 d0 0a ff 4c 8d 7b RSP: 0018:ffffc90000ed77a0 EFLAGS: 00010246 RAX: f93088cd98b5fd00 RBX: ffff88810f964800 RCX: 0000000000080000 RDX: ffffc9000f23d000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc90000ed77c8 R08: ffff8881f7052fbf R09: 1ffff1103ee0a5f7 R10: dffffc0000000000 R11: ffffed103ee0a5f8 R12: ffff88810f964800 R13: ffff88810f96483c R14: 1ffff11021f2c907 R15: 0000000000000000 FS: 00007f9b8d24e6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f35a8f57e80 CR3: 00000001359a7000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kobject_add_internal+0xb52/0xde0 lib/kobject.c:266 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:3798 do_mkdirat+0x14c/0x340 fs/namei.c:3820 __do_sys_mkdirat fs/namei.c:3831 [inline] __se_sys_mkdirat fs/namei.c:3829 [inline] __x64_sys_mkdirat+0x7b/0x90 fs/namei.c:3829 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f9b8e7f50d9 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:00007f9b8d24e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f9b8ea7cfa0 RCX: 00007f9b8e7f50d9 RDX: 00000000000001ff RSI: 0000200000000100 RDI: ffffffffffffff9c RBP: 00007f9b8e88c024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9b8ea7d038 R14: 00007f9b8ea7cfa0 R15: 00007ffc13f9ab08 ---[ end trace 88c069e38727e261 ]--- ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 9167 at lib/refcount.c:28 refcount_warn_saturate+0x120/0x1a0 lib/refcount.c:28 Modules linked in: CPU: 0 PID: 9167 Comm: syz.7.2655 Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:refcount_warn_saturate+0x120/0x1a0 lib/refcount.c:28 Code: 04 01 48 c7 c7 80 4c 40 85 e8 1c fd 3a 02 0f 0b eb c3 e8 63 a5 26 ff c6 05 61 92 82 04 01 48 c7 c7 e0 4c 40 85 e8 00 fd 3a 02 <0f> 0b eb a7 e8 47 a5 26 ff c6 05 42 92 82 04 01 48 c7 c7 00 4c 40 RSP: 0018:ffffc90000ed7780 EFLAGS: 00010246 RAX: f93088cd98b5fd00 RBX: 0000000000000003 RCX: 0000000000080000 RDX: ffffc9000f23d000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc90000ed7790 R08: ffff8881f7052fbf R09: 1ffff1103ee0a5f7 R10: dffffc0000000000 R11: ffffed103ee0a5f8 R12: 00000000c0000000 R13: ffff88810f96483c R14: 0000000000000003 R15: ffff88810f964838 FS: 00007f9b8d24e6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f35a8f57e80 CR3: 00000001359a7000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_sub_and_test include/linux/refcount.h:283 [inline] __refcount_dec_and_test include/linux/refcount.h:315 [inline] refcount_dec_and_test include/linux/refcount.h:333 [inline] kref_put include/linux/kref.h:64 [inline] kobject_put+0x231/0x270 lib/kobject.c:761 kobject_add_internal+0xb52/0xde0 lib/kobject.c:266 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:3798 do_mkdirat+0x14c/0x340 fs/namei.c:3820 __do_sys_mkdirat fs/namei.c:3831 [inline] __se_sys_mkdirat fs/namei.c:3829 [inline] __x64_sys_mkdirat+0x7b/0x90 fs/namei.c:3829 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f9b8e7f50d9 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:00007f9b8d24e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f9b8ea7cfa0 RCX: 00007f9b8e7f50d9 RDX: 00000000000001ff RSI: 0000200000000100 RDI: ffffffffffffff9c RBP: 00007f9b8e88c024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9b8ea7d038 R14: 00007f9b8ea7cfa0 R15: 00007ffc13f9ab08 ---[ end trace 88c069e38727e262 ]--- kobject_add_internal failed for android_usb (error: -2 parent: (null)) ------------[ cut here ]------------ kobject: '(null)' (ffff88810f964800): is not initialized, yet kobject_put() is being called. WARNING: CPU: 0 PID: 9167 at lib/kobject.c:760 kobject_put+0x8a/0x270 lib/kobject.c:758 Modules linked in: CPU: 0 PID: 9167 Comm: syz.7.2655 Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:kobject_put+0x8a/0x270 lib/kobject.c:758 Code: 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 d8 45 45 ff 48 8b 33 48 c7 c7 c0 9f 41 85 48 89 da e8 26 28 1f 02 <0f> 0b eb 0f e8 6d d0 0a ff e9 7c 01 00 00 e8 63 d0 0a ff 4c 8d 7b RSP: 0018:ffffc90000ed7960 EFLAGS: 00010246 RAX: f93088cd98b5fd00 RBX: ffff88810f964800 RCX: 0000000000080000 RDX: ffffc9000f23d000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc90000ed7988 R08: ffff8881f7052fbf R09: 1ffff1103ee0a5f7 R10: dffffc0000000000 R11: ffffed103ee0a5f8 R12: fffffffffffffffe R13: ffff88810f96483c R14: 1ffff11021f2c907 R15: 0000000000000000 FS: 00007f9b8d24e6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f35a8f57e80 CR3: 00000001359a7000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: put_device drivers/base/core.c:3373 [inline] device_add+0x36f/0xc00 drivers/base/core.c:3318 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:3798 do_mkdirat+0x14c/0x340 fs/namei.c:3820 __do_sys_mkdirat fs/namei.c:3831 [inline] __se_sys_mkdirat fs/namei.c:3829 [inline] __x64_sys_mkdirat+0x7b/0x90 fs/namei.c:3829 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f9b8e7f50d9 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:00007f9b8d24e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f9b8ea7cfa0 RCX: 00007f9b8e7f50d9 RDX: 00000000000001ff RSI: 0000200000000100 RDI: ffffffffffffff9c RBP: 00007f9b8e88c024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9b8ea7d038 R14: 00007f9b8ea7cfa0 R15: 00007ffc13f9ab08 ---[ end trace 88c069e38727e263 ]---