==================================================================
BUG: KASAN: use-after-free in kobject_get+0x113/0x120 lib/kobject.c:663
Read of size 1 at addr ffff8881193d283c by task syz.1.475/2271

CPU: 1 PID: 2271 Comm: syz.1.475 Tainted: G        W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
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:1354
 vfs_mkdir+0x42c/0x600 fs/namei.c:3798
 do_mkdirat+0x14c/0x340 fs/namei.c:3820
 __do_sys_mkdir fs/namei.c:3836 [inline]
 __se_sys_mkdir fs/namei.c:3834 [inline]
 __x64_sys_mkdir+0x60/0x70 fs/namei.c:3834
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f42ceb8de99
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:00007f42cd5e7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007f42cee15fa0 RCX: 00007f42ceb8de99
RDX: 0000000000000000 RSI: 00000000000001ff RDI: 0000200000000800
RBP: 00007f42cec23eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f42cee16038 R14: 00007f42cee15fa0 R15: 00007ffe35db8798

Allocated by task 1046:
 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_slab_alloc+0xb7/0xe0 mm/kasan/common.c:463
 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+0x15a/0x2d0 mm/slub.c:2965
 getname_flags+0xba/0x510 fs/namei.c:141
 getname fs/namei.c:212 [inline]
 user_path_create fs/namei.c:3673 [inline]
 do_mkdirat+0x4b/0x340 fs/namei.c:3813
 __do_sys_mkdir fs/namei.c:3836 [inline]
 __se_sys_mkdir fs/namei.c:3834 [inline]
 __x64_sys_mkdir+0x60/0x70 fs/namei.c:3834
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Freed by task 1046:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4a/0x70 mm/kasan/common.c:45
 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370
 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:362
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370
 kasan_slab_free include/linux/kasan.h:220 [inline]
 slab_free_hook mm/slub.c:1600 [inline]
 slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1626
 slab_free mm/slub.c:3208 [inline]
 kmem_cache_free+0x100/0x2d0 mm/slub.c:3224
 putname fs/namei.c:262 [inline]
 filename_create+0x443/0x680 fs/namei.c:-1
 user_path_create fs/namei.c:3673 [inline]
 do_mkdirat+0x5e/0x340 fs/namei.c:3813
 __do_sys_mkdir fs/namei.c:3836 [inline]
 __se_sys_mkdir fs/namei.c:3834 [inline]
 __x64_sys_mkdir+0x60/0x70 fs/namei.c:3834
 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 ffff8881193d2200
 which belongs to the cache names_cache of size 4096
The buggy address is located 1596 bytes inside of
 4096-byte region [ffff8881193d2200, ffff8881193d3200)
The buggy address belongs to the page:
page:ffffea000464f400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1193d0
head:ffffea000464f400 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head)
raw: 4000000000010200 dead000000000100 dead000000000122 ffff88810018b980
raw: 0000000000000000 0000000000070007 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 1046, ts 129192529802, free_ts 129181291947
 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]
 kmem_cache_alloc+0x1a4/0x2d0 mm/slub.c:2965
 getname_flags+0xba/0x510 fs/namei.c:141
 getname fs/namei.c:212 [inline]
 user_path_create fs/namei.c:3673 [inline]
 do_symlinkat+0x7a/0x3d0 fs/namei.c:4127
 __do_sys_symlink fs/namei.c:4153 [inline]
 __se_sys_symlink fs/namei.c:4151 [inline]
 __x64_sys_symlink+0x60/0x70 fs/namei.c:4151
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
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+0x29/0x40 mm/slub.c:1920
 __slab_free+0x313/0x3a0 mm/slub.c:3136
 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+0x15a/0x2d0 mm/slub.c:2965
 f2fs_kmem_cache_alloc fs/f2fs/f2fs.h:-1 [inline]
 add_free_nid+0xec/0x690 fs/f2fs/node.c:2311
 scan_nat_page fs/f2fs/node.c:2410 [inline]
 __f2fs_build_free_nids fs/f2fs/node.c:2516 [inline]
 f2fs_build_free_nids+0xf3f/0x1470 fs/f2fs/node.c:2554
 f2fs_build_node_manager+0x15c9/0x1d20 fs/f2fs/node.c:3341
 f2fs_fill_super+0x4a3e/0x73d0 fs/f2fs/super.c:4323

Memory state around the buggy address:
 ffff8881193d2700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881193d2780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881193d2800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                        ^
 ffff8881193d2880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881193d2900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
------------[ cut here ]------------
kobject: '(null)' (ffff8881193d2800): is not initialized, yet kobject_get() is being called.
WARNING: CPU: 1 PID: 2271 at lib/kobject.c:666 kobject_get+0x7c/0x120 lib/kobject.c:664
Modules linked in:
CPU: 1 PID: 2271 Comm: syz.1.475 Tainted: G    B   W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
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 16 31 45 ff 48 8b 33 48 c7 c7 c0 9b 41 85 48 89 da e8 e4 fc 1e 02 <0f> 0b eb 0c e8 db bb 0a ff eb 4c e8 d4 bb 0a ff 4c 8d 73 38 4c 89
RSP: 0018:ffffc90000d77970 EFLAGS: 00010246
RAX: a8dd13c42796b800 RBX: ffff8881193d2800 RCX: 0000000000080000
RDX: ffffc90001d93000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90000d77988 R08: ffffc90000d77307 R09: fffff520001aee94
R10: dffffc0000000000 R11: fffff520001aee61 R12: 0000000000000000
R13: ffff8881263a0068 R14: 0000000000000000 R15: dffffc0000000000
FS:  00007f42cd5e76c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb9949016a0 CR3: 000000011e093000 CR4: 00000000003506a0
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:1354
 vfs_mkdir+0x42c/0x600 fs/namei.c:3798
 do_mkdirat+0x14c/0x340 fs/namei.c:3820
 __do_sys_mkdir fs/namei.c:3836 [inline]
 __se_sys_mkdir fs/namei.c:3834 [inline]
 __x64_sys_mkdir+0x60/0x70 fs/namei.c:3834
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f42ceb8de99
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:00007f42cd5e7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007f42cee15fa0 RCX: 00007f42ceb8de99
RDX: 0000000000000000 RSI: 00000000000001ff RDI: 0000200000000800
RBP: 00007f42cec23eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f42cee16038 R14: 00007f42cee15fa0 R15: 00007ffe35db8798
---[ end trace b7e4836f70e88582 ]---
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 2271 at lib/refcount.c:25 refcount_warn_saturate+0x104/0x1a0 lib/refcount.c:25
Modules linked in:
CPU: 0 PID: 2271 Comm: syz.1.475 Tainted: G    B   W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:refcount_warn_saturate+0x104/0x1a0 lib/refcount.c:25
Code: 04 01 48 c7 c7 a0 49 40 85 e8 98 ca 3a 02 0f 0b eb df e8 8f 89 26 ff c6 05 cc 75 82 04 01 48 c7 c7 e0 48 40 85 e8 7c ca 3a 02 <0f> 0b eb c3 e8 73 89 26 ff c6 05 b1 75 82 04 01 48 c7 c7 40 49 40
RSP: 0018:ffffc90000d77950 EFLAGS: 00010246
RAX: a8dd13c42796b800 RBX: 0000000000000002 RCX: 0000000000080000
RDX: ffffc90001d93000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90000d77960 R08: ffff8881f7027453 R09: 1ffff1103ee04e8a
R10: dffffc0000000000 R11: ffffed103ee04e8b R12: 0000000000000000
R13: ffff8881263a0068 R14: 0000000000000002 R15: 0000000000000000
FS:  00007f42cd5e76c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f83825382f8 CR3: 000000011e093000 CR4: 00000000003506a0
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:1354
 vfs_mkdir+0x42c/0x600 fs/namei.c:3798
 do_mkdirat+0x14c/0x340 fs/namei.c:3820
 __do_sys_mkdir fs/namei.c:3836 [inline]
 __se_sys_mkdir fs/namei.c:3834 [inline]
 __x64_sys_mkdir+0x60/0x70 fs/namei.c:3834
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f42ceb8de99
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:00007f42cd5e7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007f42cee15fa0 RCX: 00007f42ceb8de99
RDX: 0000000000000000 RSI: 00000000000001ff RDI: 0000200000000800
RBP: 00007f42cec23eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f42cee16038 R14: 00007f42cee15fa0 R15: 00007ffe35db8798
---[ end trace b7e4836f70e88583 ]---
------------[ cut here ]------------
kobject: '(null)' (ffff8881193d2800): is not initialized, yet kobject_get() is being called.
WARNING: CPU: 1 PID: 2271 at lib/kobject.c:666 kobject_get lib/kobject.c:664 [inline]
WARNING: CPU: 1 PID: 2271 at lib/kobject.c:666 kobject_add_internal+0x12e/0xde0 lib/kobject.c:248
Modules linked in:
CPU: 1 PID: 2271 Comm: syz.1.475 Tainted: G    B   W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
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 95 18 45 ff 49 8b 34 24 48 c7 c7 c0 9b 41 85 4c 89 e2 e8 62 e4 1e 02 <0f> 0b e9 04 01 00 00 e8 56 a3 0a ff b8 fe ff ff ff e9 b0 09 00 00
RSP: 0018:ffffc90000d777d8 EFLAGS: 00010246
RAX: a8dd13c42796b800 RBX: ffff8881085ab200 RCX: 0000000000080000
RDX: ffffc90001d93000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90000d77830 R08: ffff8881f7152fbf R09: 1ffff1103ee2a5f7
R10: dffffc0000000000 R11: ffffed103ee2a5f8 R12: ffff8881193d2800
R13: ffff8881085ab218 R14: 0000000000000000 R15: 1ffff110210b5640
FS:  00007f42cd5e76c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f83825382f8 CR3: 000000011e093000 CR4: 00000000003506a0
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:1354
 vfs_mkdir+0x42c/0x600 fs/namei.c:3798
 do_mkdirat+0x14c/0x340 fs/namei.c:3820
 __do_sys_mkdir fs/namei.c:3836 [inline]
 __se_sys_mkdir fs/namei.c:3834 [inline]
 __x64_sys_mkdir+0x60/0x70 fs/namei.c:3834
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f42ceb8de99
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:00007f42cd5e7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007f42cee15fa0 RCX: 00007f42ceb8de99
RDX: 0000000000000000 RSI: 00000000000001ff RDI: 0000200000000800
RBP: 00007f42cec23eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f42cee16038 R14: 00007f42cee15fa0 R15: 00007ffe35db8798
---[ end trace b7e4836f70e88584 ]---
------------[ cut here ]------------
refcount_t: saturated; leaking memory.
WARNING: CPU: 1 PID: 2271 at lib/refcount.c:22 refcount_warn_saturate+0x158/0x1a0 lib/refcount.c:22
Modules linked in:
CPU: 1 PID: 2271 Comm: syz.1.475 Tainted: G    B   W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:refcount_warn_saturate+0x158/0x1a0 lib/refcount.c:22
Code: 04 01 48 c7 c7 60 48 40 85 e8 44 ca 3a 02 0f 0b eb 8b e8 3b 89 26 ff c6 05 77 75 82 04 01 48 c7 c7 60 48 40 85 e8 28 ca 3a 02 <0f> 0b e9 6c ff ff ff e8 1c 89 26 ff c6 05 5c 75 82 04 01 48 c7 c7
RSP: 0018:ffffc90000d777b8 EFLAGS: 00010246
RAX: a8dd13c42796b800 RBX: 0000000000000001 RCX: 0000000000080000
RDX: ffffc90001d93000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90000d777c8 R08: ffff8881f7152fbf R09: 1ffff1103ee2a5f7
R10: dffffc0000000000 R11: ffffed103ee2a5f8 R12: 00000000c0000000
R13: ffff8881085ab218 R14: 0000000000000001 R15: ffff8881193d2838
FS:  00007f42cd5e76c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f83825382f8 CR3: 000000011e093000 CR4: 00000000003506a0
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:1354
 vfs_mkdir+0x42c/0x600 fs/namei.c:3798
 do_mkdirat+0x14c/0x340 fs/namei.c:3820
 __do_sys_mkdir fs/namei.c:3836 [inline]
 __se_sys_mkdir fs/namei.c:3834 [inline]
 __x64_sys_mkdir+0x60/0x70 fs/namei.c:3834
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f42ceb8de99
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:00007f42cd5e7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007f42cee15fa0 RCX: 00007f42ceb8de99
RDX: 0000000000000000 RSI: 00000000000001ff RDI: 0000200000000800
RBP: 00007f42cec23eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f42cee16038 R14: 00007f42cee15fa0 R15: 00007ffe35db8798
---[ end trace b7e4836f70e88585 ]---
------------[ cut here ]------------
kobject: '(null)' (ffff8881193d2800): is not initialized, yet kobject_put() is being called.
WARNING: CPU: 0 PID: 2271 at lib/kobject.c:760 kobject_put+0x8a/0x270 lib/kobject.c:758
Modules linked in:
CPU: 0 PID: 2271 Comm: syz.1.475 Tainted: G    B   W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
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 e8 2f 45 ff 48 8b 33 48 c7 c7 40 9c 41 85 48 89 da e8 b6 fb 1e 02 <0f> 0b eb 0f e8 ad ba 0a ff e9 7c 01 00 00 e8 a3 ba 0a ff 4c 8d 7b
RSP: 0018:ffffc90000d777a0 EFLAGS: 00010246
RAX: a8dd13c42796b800 RBX: ffff8881193d2800 RCX: 0000000000080000
RDX: ffffc90001d93000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90000d777c8 R08: ffff8881f7052fbf R09: 1ffff1103ee0a5f7
R10: dffffc0000000000 R11: ffffed103ee0a5f8 R12: ffff8881193d2800
R13: ffff8881193d283c R14: 1ffff1102327a507 R15: 0000000000000000
FS:  00007f42cd5e76c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555586054908 CR3: 000000011e093000 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:1354
 vfs_mkdir+0x42c/0x600 fs/namei.c:3798
 do_mkdirat+0x14c/0x340 fs/namei.c:3820
 __do_sys_mkdir fs/namei.c:3836 [inline]
 __se_sys_mkdir fs/namei.c:3834 [inline]
 __x64_sys_mkdir+0x60/0x70 fs/namei.c:3834
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f42ceb8de99
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:00007f42cd5e7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007f42cee15fa0 RCX: 00007f42ceb8de99
RDX: 0000000000000000 RSI: 00000000000001ff RDI: 0000200000000800
RBP: 00007f42cec23eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f42cee16038 R14: 00007f42cee15fa0 R15: 00007ffe35db8798
---[ end trace b7e4836f70e88586 ]---
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 1 PID: 2271 at lib/refcount.c:28 refcount_warn_saturate+0x120/0x1a0 lib/refcount.c:28
Modules linked in:
CPU: 1 PID: 2271 Comm: syz.1.475 Tainted: G    B   W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:refcount_warn_saturate+0x120/0x1a0 lib/refcount.c:28
Code: 04 01 48 c7 c7 e0 48 40 85 e8 7c ca 3a 02 0f 0b eb c3 e8 73 89 26 ff c6 05 b1 75 82 04 01 48 c7 c7 40 49 40 85 e8 60 ca 3a 02 <0f> 0b eb a7 e8 57 89 26 ff c6 05 92 75 82 04 01 48 c7 c7 60 48 40
RSP: 0018:ffffc90000d77780 EFLAGS: 00010246
RAX: a8dd13c42796b800 RBX: 0000000000000003 RCX: 0000000000080000
RDX: ffffc90001d93000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90000d77790 R08: ffffc90000d77107 R09: fffff520001aee54
R10: dffffc0000000000 R11: fffff520001aee21 R12: 00000000c0000000
R13: ffff8881193d283c R14: 0000000000000003 R15: ffff8881193d2838
FS:  00007f42cd5e76c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbfd5cc22f8 CR3: 000000011e093000 CR4: 00000000003506a0
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:1354
 vfs_mkdir+0x42c/0x600 fs/namei.c:3798
 do_mkdirat+0x14c/0x340 fs/namei.c:3820
 __do_sys_mkdir fs/namei.c:3836 [inline]
 __se_sys_mkdir fs/namei.c:3834 [inline]
 __x64_sys_mkdir+0x60/0x70 fs/namei.c:3834
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f42ceb8de99
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:00007f42cd5e7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007f42cee15fa0 RCX: 00007f42ceb8de99
RDX: 0000000000000000 RSI: 00000000000001ff RDI: 0000200000000800
RBP: 00007f42cec23eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f42cee16038 R14: 00007f42cee15fa0 R15: 00007ffe35db8798
---[ end trace b7e4836f70e88587 ]---
kobject_add_internal failed for android_usb (error: -2 parent: (null))
------------[ cut here ]------------
kobject: '(null)' (ffff8881193d2800): is not initialized, yet kobject_put() is being called.
WARNING: CPU: 1 PID: 2271 at lib/kobject.c:760 kobject_put+0x8a/0x270 lib/kobject.c:758
Modules linked in:
CPU: 1 PID: 2271 Comm: syz.1.475 Tainted: G    B   W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
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 e8 2f 45 ff 48 8b 33 48 c7 c7 40 9c 41 85 48 89 da e8 b6 fb 1e 02 <0f> 0b eb 0f e8 ad ba 0a ff e9 7c 01 00 00 e8 a3 ba 0a ff 4c 8d 7b
RSP: 0018:ffffc90000d77960 EFLAGS: 00010246
RAX: a8dd13c42796b800 RBX: ffff8881193d2800 RCX: 0000000000080000
RDX: ffffc90001d93000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90000d77988 R08: ffffc90000d772e7 R09: fffff520001aee90
R10: dffffc0000000000 R11: fffff520001aee5d R12: fffffffffffffffe
R13: ffff8881193d283c R14: 1ffff1102327a507 R15: 0000000000000000
FS:  00007f42cd5e76c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbfd5cc22f8 CR3: 000000011e093000 CR4: 00000000003506a0
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:1354
 vfs_mkdir+0x42c/0x600 fs/namei.c:3798
 do_mkdirat+0x14c/0x340 fs/namei.c:3820
 __do_sys_mkdir fs/namei.c:3836 [inline]
 __se_sys_mkdir fs/namei.c:3834 [inline]
 __x64_sys_mkdir+0x60/0x70 fs/namei.c:3834
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f42ceb8de99
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:00007f42cd5e7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007f42cee15fa0 RCX: 00007f42ceb8de99
RDX: 0000000000000000 RSI: 00000000000001ff RDI: 0000200000000800
RBP: 00007f42cec23eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f42cee16038 R14: 00007f42cee15fa0 R15: 00007ffe35db8798
---[ end trace b7e4836f70e88588 ]---