==================================================================
BUG: KASAN: use-after-free in kobject_get+0x113/0x120 lib/kobject.c:663
Read of size 1 at addr ffff88811c54903c by task syz.1.4693/18316
CPU: 0 PID: 18316 Comm: syz.1.4693 Tainted: G W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
__dump_stack+0x21/0x30 lib/dump_stack.c:88
dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106
print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
__kasan_report mm/kasan/report.c:427 [inline]
kasan_report+0x10f/0x150 mm/kasan/report.c:444
__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:3518 [inline]
device_add+0x2f0/0xe90 drivers/base/core.c:3342
device_create_groups_vargs drivers/base/core.c:4118 [inline]
device_create+0x26c/0x300 drivers/base/core.c:4160
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:642
configfs_mkdir+0x50a/0x9c0 fs/configfs/dir.c:1360
vfs_mkdir+0x38b/0x590 fs/namei.c:4073
do_mkdirat+0x174/0x4d0 fs/namei.c:4098
__do_sys_mkdirat fs/namei.c:4113 [inline]
__se_sys_mkdirat fs/namei.c:4111 [inline]
__x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4111
x64_sys_call+0x37e/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:259
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f0c51f781d9
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:00007f0c509d1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f0c521fffa0 RCX: 00007f0c51f781d9
RDX: 00000000000001ff RSI: 0000200000000240 RDI: ffffffffffffff9c
RBP: 00007f0c5200f888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0c52200038 R14: 00007f0c521fffa0 R15: 00007fffebc4e448
Allocated by task 18264:
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:433 [inline]
____kasan_kmalloc mm/kasan/common.c:512 [inline]
__kasan_kmalloc+0xd4/0x100 mm/kasan/common.c:521
kasan_kmalloc include/linux/kasan.h:227 [inline]
kmem_cache_alloc_trace+0x119/0x270 mm/slub.c:3274
kmalloc include/linux/slab.h:619 [inline]
kzalloc include/linux/slab.h:750 [inline]
uinput_open+0x56/0x1b0 drivers/input/misc/uinput.c:402
misc_open+0x325/0x3a0 drivers/char/misc.c:143
chrdev_open+0x585/0x5f0 fs/char_dev.c:414
do_dentry_open+0x82a/0x1010 fs/open.c:828
vfs_open+0x73/0x80 fs/open.c:960
do_open fs/namei.c:3616 [inline]
path_openat+0x26e6/0x2f80 fs/namei.c:3750
do_filp_open+0x1df/0x400 fs/namei.c:3777
do_sys_openat2+0x15e/0x7f0 fs/open.c:1236
do_sys_open fs/open.c:1252 [inline]
__do_sys_openat fs/open.c:1268 [inline]
__se_sys_openat fs/open.c:1263 [inline]
__x64_sys_openat+0x136/0x160 fs/open.c:1263
x64_sys_call+0x219/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:258
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
Freed by task 18262:
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:365
__kasan_slab_free+0x11/0x20 mm/kasan/common.c:373
kasan_slab_free include/linux/kasan.h:193 [inline]
slab_free_hook mm/slub.c:1728 [inline]
slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1754
slab_free mm/slub.c:3526 [inline]
kfree+0xc4/0x270 mm/slub.c:4588
uinput_release+0x46/0x50 drivers/input/misc/uinput.c:780
__fput+0x22b/0x900 fs/file_table.c:311
____fput+0x15/0x20 fs/file_table.c:339
task_work_run+0x127/0x190 kernel/task_work.c:188
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop+0xd0/0xe0 kernel/entry/common.c:184
exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:217
__syscall_exit_to_user_mode_work kernel/entry/common.c:299 [inline]
syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:310
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
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
insert_work+0x51/0x310 kernel/workqueue.c:1373
__queue_work+0x8e1/0xc60 kernel/workqueue.c:1539
queue_work_on+0xde/0x150 kernel/workqueue.c:1566
queue_work include/linux/workqueue.h:510 [inline]
schedule_work include/linux/workqueue.h:571 [inline]
bpf_prog_free+0x13c/0x150 kernel/bpf/core.c:2327
__bpf_prog_put_rcu+0xaf/0xc0 kernel/bpf/syscall.c:1764
rcu_do_batch+0x4c1/0xbf0 kernel/rcu/tree.c:2523
rcu_core+0x4a3/0xef0 kernel/rcu/tree.c:2763
rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2776
handle_softirqs+0x250/0x560 kernel/softirq.c:583
run_ksoftirqd+0x28/0x40 kernel/softirq.c:959
smpboot_thread_fn+0x446/0x880 kernel/smpboot.c:164
kthread+0x3f5/0x4f0 kernel/kthread.c:337
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Second to 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
__call_rcu_common kernel/rcu/tree.c:3011 [inline]
call_rcu+0x10b/0xf60 kernel/rcu/tree.c:3129
__bpf_prog_put_noref+0x286/0x2b0 kernel/bpf/syscall.c:1781
bpf_prog_put_deferred+0x2e0/0x3c0 kernel/bpf/syscall.c:1797
__bpf_prog_put kernel/bpf/syscall.c:1809 [inline]
bpf_prog_put kernel/bpf/syscall.c:1816 [inline]
bpf_prog_release+0x24f/0x260 kernel/bpf/syscall.c:1824
__fput+0x22b/0x900 fs/file_table.c:311
____fput+0x15/0x20 fs/file_table.c:339
task_work_run+0x127/0x190 kernel/task_work.c:188
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop+0xd0/0xe0 kernel/entry/common.c:184
exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:217
__syscall_exit_to_user_mode_work kernel/entry/common.c:299 [inline]
syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:310
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
The buggy address belongs to the object at ffff88811c549000
which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 60 bytes inside of
1024-byte region [ffff88811c549000, ffff88811c549400)
The buggy address belongs to the page:
page:ffffea0004715200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11c548
head:ffffea0004715200 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head|zone=1)
raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100043080
raw: 0000000000000000 0000000000100010 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 13679, ts 507920632238, free_ts 507909380154
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2607
prep_new_page+0x1c/0x110 mm/page_alloc.c:2613
get_page_from_freelist+0x2c3a/0x2cd0 mm/page_alloc.c:4487
__alloc_pages+0x1a2/0x460 mm/page_alloc.c:5824
alloc_slab_page mm/slub.c:-1 [inline]
allocate_slab mm/slub.c:1937 [inline]
new_slab+0xa0/0x4d0 mm/slub.c:2000
___slab_alloc+0x3ac/0x840 mm/slub.c:3033
__slab_alloc+0x49/0x90 mm/slub.c:3120
slab_alloc_node mm/slub.c:3211 [inline]
slab_alloc mm/slub.c:3255 [inline]
__kmalloc_track_caller+0x169/0x2c0 mm/slub.c:4954
kmalloc_reserve net/core/skbuff.c:357 [inline]
__alloc_skb+0x210/0x730 net/core/skbuff.c:428
alloc_skb_fclone include/linux/skbuff.h:1233 [inline]
sk_stream_alloc_skb+0x216/0xb70 net/ipv4/tcp.c:892
tcp_sendmsg_locked+0xcbb/0x3330 net/ipv4/tcp.c:1317
tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1460
inet_sendmsg+0xa5/0xc0 net/ipv4/af_inet.c:830
sock_sendmsg_nosec net/socket.c:704 [inline]
__sock_sendmsg net/socket.c:716 [inline]
__sys_sendto+0x46d/0x620 net/socket.c:2063
__do_sys_sendto net/socket.c:2075 [inline]
__se_sys_sendto net/socket.c:2071 [inline]
__x64_sys_sendto+0xe5/0x100 net/socket.c:2071
x64_sys_call+0x178/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:45
page last free stack trace:
reset_page_owner include/linux/page_owner.h:26 [inline]
free_pages_prepare mm/page_alloc.c:1474 [inline]
free_pcp_prepare mm/page_alloc.c:1546 [inline]
free_unref_page_prepare+0x5fa/0x600 mm/page_alloc.c:3536
free_unref_page+0xae/0x540 mm/page_alloc.c:3618
free_the_page mm/page_alloc.c:805 [inline]
__free_pages+0x6c/0x100 mm/page_alloc.c:5900
__free_slab+0xe5/0x1e0 mm/slub.c:2025
free_slab mm/slub.c:2040 [inline]
discard_slab+0x29/0x40 mm/slub.c:2046
__slab_free+0x211/0x290 mm/slub.c:3431
do_slab_free mm/slub.c:3514 [inline]
___cache_free+0x104/0x120 mm/slub.c:3535
qlink_free+0x4d/0x90 mm/kasan/quarantine.c:157
qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176
kasan_quarantine_reduce+0x14a/0x170 mm/kasan/quarantine.c:283
__kasan_slab_alloc+0x2f/0xe0 mm/kasan/common.c:443
kasan_slab_alloc include/linux/kasan.h:217 [inline]
slab_post_alloc_hook+0x4f/0x2b0 mm/slab.h:550
slab_alloc_node mm/slub.c:3245 [inline]
slab_alloc mm/slub.c:3255 [inline]
__kmalloc_track_caller+0x11f/0x2c0 mm/slub.c:4954
kmalloc_reserve net/core/skbuff.c:357 [inline]
__alloc_skb+0x210/0x730 net/core/skbuff.c:428
alloc_skb_fclone include/linux/skbuff.h:1233 [inline]
sk_stream_alloc_skb+0x216/0xb70 net/ipv4/tcp.c:892
tcp_sendmsg_locked+0xcbb/0x3330 net/ipv4/tcp.c:1317
Memory state around the buggy address:
ffff88811c548f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88811c548f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88811c549000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88811c549080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88811c549100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
------------[ cut here ]------------
kobject: '' (ffff88811c549000): is not initialized, yet kobject_get() is being called.
WARNING: CPU: 1 PID: 18316 at lib/kobject.c:666 kobject_get+0x7c/0x120 lib/kobject.c:664
Modules linked in:
CPU: 1 PID: 18316 Comm: syz.1.4693 Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:kobject_get+0x7c/0x120 lib/kobject.c:664
Code: f9 fe 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 56 4b 39 ff 48 8b 33 48 c7 c7 60 d4 64 85 48 89 da e8 84 9d 3b 02 <0f> 0b eb 0c e8 9b ca f9 fe eb 4c e8 94 ca f9 fe 4c 8d 73 38 4c 89
RSP: 0018:ffffc90001567a18 EFLAGS: 00010246
RAX: ddd3885a73829400 RBX: ffff88811c549000 RCX: 0000000000080000
RDX: ffffc90002ddd000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90001567a30 R08: ffffc90001567487 R09: 1ffff920002ace90
R10: dffffc0000000000 R11: fffff520002ace91 R12: 1ffff1102aa7d80e
R13: dffffc0000000000 R14: 0000000000000000 R15: dffffc0000000000
FS: 00007f0c509d16c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc76aafd60 CR3: 00000001265d0000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
get_device drivers/base/core.c:3518 [inline]
device_add+0x2f0/0xe90 drivers/base/core.c:3342
device_create_groups_vargs drivers/base/core.c:4118 [inline]
device_create+0x26c/0x300 drivers/base/core.c:4160
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:642
configfs_mkdir+0x50a/0x9c0 fs/configfs/dir.c:1360
vfs_mkdir+0x38b/0x590 fs/namei.c:4073
do_mkdirat+0x174/0x4d0 fs/namei.c:4098
__do_sys_mkdirat fs/namei.c:4113 [inline]
__se_sys_mkdirat fs/namei.c:4111 [inline]
__x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4111
x64_sys_call+0x37e/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:259
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f0c51f781d9
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:00007f0c509d1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f0c521fffa0 RCX: 00007f0c51f781d9
RDX: 00000000000001ff RSI: 0000200000000240 RDI: ffffffffffffff9c
RBP: 00007f0c5200f888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0c52200038 R14: 00007f0c521fffa0 R15: 00007fffebc4e448
---[ end trace 4aa52aec415e5b27 ]---
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 18316 at lib/refcount.c:25 refcount_warn_saturate+0x104/0x1a0 lib/refcount.c:25
Modules linked in:
CPU: 1 PID: 18316 Comm: syz.1.4693 Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:refcount_warn_saturate+0x104/0x1a0 lib/refcount.c:25
Code: 04 01 48 c7 c7 20 59 63 85 e8 f8 4e 5b 02 0f 0b eb df e8 0f 7c 19 ff c6 05 0d d9 95 04 01 48 c7 c7 60 58 63 85 e8 dc 4e 5b 02 <0f> 0b eb c3 e8 f3 7b 19 ff c6 05 f2 d8 95 04 01 48 c7 c7 c0 58 63
RSP: 0018:ffffc900015679f8 EFLAGS: 00010246
RAX: ddd3885a73829400 RBX: 0000000000000002 RCX: 0000000000080000
RDX: ffffc90002ddd000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90001567a08 R08: ffffc90001567467 R09: 1ffff920002ace8c
R10: dffffc0000000000 R11: fffff520002ace8d R12: 1ffff1102aa7d80e
R13: dffffc0000000000 R14: 0000000000000002 R15: 0000000000000000
FS: 00007f0c509d16c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc76aafd60 CR3: 00000001265d0000 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:3518 [inline]
device_add+0x2f0/0xe90 drivers/base/core.c:3342
device_create_groups_vargs drivers/base/core.c:4118 [inline]
device_create+0x26c/0x300 drivers/base/core.c:4160
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:642
configfs_mkdir+0x50a/0x9c0 fs/configfs/dir.c:1360
vfs_mkdir+0x38b/0x590 fs/namei.c:4073
do_mkdirat+0x174/0x4d0 fs/namei.c:4098
__do_sys_mkdirat fs/namei.c:4113 [inline]
__se_sys_mkdirat fs/namei.c:4111 [inline]
__x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4111
x64_sys_call+0x37e/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:259
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f0c51f781d9
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:00007f0c509d1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f0c521fffa0 RCX: 00007f0c51f781d9
RDX: 00000000000001ff RSI: 0000200000000240 RDI: ffffffffffffff9c
RBP: 00007f0c5200f888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0c52200038 R14: 00007f0c521fffa0 R15: 00007fffebc4e448
---[ end trace 4aa52aec415e5b28 ]---
------------[ cut here ]------------
kobject: '' (ffff88811c549000): is not initialized, yet kobject_get() is being called.
WARNING: CPU: 1 PID: 18316 at lib/kobject.c:666 kobject_get lib/kobject.c:664 [inline]
WARNING: CPU: 1 PID: 18316 at lib/kobject.c:666 kobject_add_internal+0x12e/0xde0 lib/kobject.c:248
Modules linked in:
CPU: 1 PID: 18316 Comm: syz.1.4693 Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
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 d5 32 39 ff 49 8b 34 24 48 c7 c7 60 d4 64 85 4c 89 e2 e8 02 85 3b 02 <0f> 0b e9 04 01 00 00 e8 16 b2 f9 fe b8 fe ff ff ff e9 b0 09 00 00
RSP: 0018:ffffc90001567898 EFLAGS: 00010246
RAX: ddd3885a73829400 RBX: ffff88811f837100 RCX: 0000000000080000
RDX: ffffc90002ddd000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc900015678f0 R08: ffff8881f7132eff R09: 1ffff1103ee265df
R10: dffffc0000000000 R11: ffffed103ee265e0 R12: ffff88811c549000
R13: ffff88811f837118 R14: 0000000000000000 R15: 1ffff11023f06e20
FS: 00007f0c509d16c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc76aafd60 CR3: 00000001265d0000 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:2976 [inline]
get_device_parent+0x3a6/0x410 drivers/base/core.c:3031
device_add+0x308/0xe90 drivers/base/core.c:3343
device_create_groups_vargs drivers/base/core.c:4118 [inline]
device_create+0x26c/0x300 drivers/base/core.c:4160
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:642
configfs_mkdir+0x50a/0x9c0 fs/configfs/dir.c:1360
vfs_mkdir+0x38b/0x590 fs/namei.c:4073
do_mkdirat+0x174/0x4d0 fs/namei.c:4098
__do_sys_mkdirat fs/namei.c:4113 [inline]
__se_sys_mkdirat fs/namei.c:4111 [inline]
__x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4111
x64_sys_call+0x37e/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:259
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f0c51f781d9
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:00007f0c509d1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f0c521fffa0 RCX: 00007f0c51f781d9
RDX: 00000000000001ff RSI: 0000200000000240 RDI: ffffffffffffff9c
RBP: 00007f0c5200f888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0c52200038 R14: 00007f0c521fffa0 R15: 00007fffebc4e448
---[ end trace 4aa52aec415e5b29 ]---
------------[ cut here ]------------
refcount_t: saturated; leaking memory.
WARNING: CPU: 1 PID: 18316 at lib/refcount.c:22 refcount_warn_saturate+0x158/0x1a0 lib/refcount.c:22
Modules linked in:
CPU: 1 PID: 18316 Comm: syz.1.4693 Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:refcount_warn_saturate+0x158/0x1a0 lib/refcount.c:22
Code: 04 01 48 c7 c7 00 58 63 85 e8 a4 4e 5b 02 0f 0b eb 8b e8 bb 7b 19 ff c6 05 b8 d8 95 04 01 48 c7 c7 00 58 63 85 e8 88 4e 5b 02 <0f> 0b e9 6c ff ff ff e8 9c 7b 19 ff c6 05 9d d8 95 04 01 48 c7 c7
RSP: 0018:ffffc90001567878 EFLAGS: 00010246
RAX: ddd3885a73829400 RBX: 0000000000000001 RCX: 0000000000080000
RDX: ffffc90002ddd000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90001567888 R08: ffffc900015672e7 R09: 1ffff920002ace5c
R10: dffffc0000000000 R11: fffff520002ace5d R12: 00000000c0000000
R13: ffff88811f837118 R14: 0000000000000001 R15: ffff88811c549038
FS: 00007f0c509d16c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc76aafd60 CR3: 00000001265d0000 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:2976 [inline]
get_device_parent+0x3a6/0x410 drivers/base/core.c:3031
device_add+0x308/0xe90 drivers/base/core.c:3343
device_create_groups_vargs drivers/base/core.c:4118 [inline]
device_create+0x26c/0x300 drivers/base/core.c:4160
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:642
configfs_mkdir+0x50a/0x9c0 fs/configfs/dir.c:1360
vfs_mkdir+0x38b/0x590 fs/namei.c:4073
do_mkdirat+0x174/0x4d0 fs/namei.c:4098
__do_sys_mkdirat fs/namei.c:4113 [inline]
__se_sys_mkdirat fs/namei.c:4111 [inline]
__x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4111
x64_sys_call+0x37e/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:259
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f0c51f781d9
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:00007f0c509d1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f0c521fffa0 RCX: 00007f0c51f781d9
RDX: 00000000000001ff RSI: 0000200000000240 RDI: ffffffffffffff9c
RBP: 00007f0c5200f888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0c52200038 R14: 00007f0c521fffa0 R15: 00007fffebc4e448
---[ end trace 4aa52aec415e5b2a ]---
------------[ cut here ]------------
kobject: '' (ffff88811c549000): is not initialized, yet kobject_put() is being called.
WARNING: CPU: 1 PID: 18316 at lib/kobject.c:760 kobject_put+0x8a/0x270 lib/kobject.c:758
Modules linked in:
CPU: 1 PID: 18316 Comm: syz.1.4693 Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
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 28 4a 39 ff 48 8b 33 48 c7 c7 e0 d4 64 85 48 89 da e8 56 9c 3b 02 <0f> 0b eb 0f e8 6d c9 f9 fe e9 7c 01 00 00 e8 63 c9 f9 fe 4c 8d 7b
RSP: 0018:ffffc90001567860 EFLAGS: 00010246
RAX: ddd3885a73829400 RBX: ffff88811c549000 RCX: 0000000000080000
RDX: ffffc90002ddd000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90001567888 R08: ffff8881f7132eff R09: 1ffff1103ee265df
R10: dffffc0000000000 R11: ffffed103ee265e0 R12: ffff88811c549000
R13: ffff88811c54903c R14: 1ffff110238a9207 R15: 0000000000000000
FS: 00007f0c509d16c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc76aafd60 CR3: 00000001265d0000 CR4: 00000000003506a0
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:2976 [inline]
get_device_parent+0x3a6/0x410 drivers/base/core.c:3031
device_add+0x308/0xe90 drivers/base/core.c:3343
device_create_groups_vargs drivers/base/core.c:4118 [inline]
device_create+0x26c/0x300 drivers/base/core.c:4160
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:642
configfs_mkdir+0x50a/0x9c0 fs/configfs/dir.c:1360
vfs_mkdir+0x38b/0x590 fs/namei.c:4073
do_mkdirat+0x174/0x4d0 fs/namei.c:4098
__do_sys_mkdirat fs/namei.c:4113 [inline]
__se_sys_mkdirat fs/namei.c:4111 [inline]
__x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4111
x64_sys_call+0x37e/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:259
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f0c51f781d9
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:00007f0c509d1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f0c521fffa0 RCX: 00007f0c51f781d9
RDX: 00000000000001ff RSI: 0000200000000240 RDI: ffffffffffffff9c
RBP: 00007f0c5200f888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0c52200038 R14: 00007f0c521fffa0 R15: 00007fffebc4e448
---[ end trace 4aa52aec415e5b2b ]---
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 18316 at lib/refcount.c:28 refcount_warn_saturate+0x120/0x1a0 lib/refcount.c:28
Modules linked in:
CPU: 0 PID: 18316 Comm: syz.1.4693 Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:refcount_warn_saturate+0x120/0x1a0 lib/refcount.c:28
Code: 04 01 48 c7 c7 60 58 63 85 e8 dc 4e 5b 02 0f 0b eb c3 e8 f3 7b 19 ff c6 05 f2 d8 95 04 01 48 c7 c7 c0 58 63 85 e8 c0 4e 5b 02 <0f> 0b eb a7 e8 d7 7b 19 ff c6 05 d3 d8 95 04 01 48 c7 c7 00 58 63
RSP: 0018:ffffc90001567840 EFLAGS: 00010246
RAX: ddd3885a73829400 RBX: 0000000000000003 RCX: 0000000000080000
RDX: ffffc90002ddd000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90001567850 R08: ffffc900015672a7 R09: 1ffff920002ace54
R10: dffffc0000000000 R11: fffff520002ace55 R12: 00000000c0000000
R13: ffff88811c54903c R14: 0000000000000003 R15: ffff88811c549038
FS: 00007f0c509d16c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcac72f32f8 CR3: 00000001265d0000 CR4: 00000000003506b0
DR0: 0000000080000001 DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 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:2976 [inline]
get_device_parent+0x3a6/0x410 drivers/base/core.c:3031
device_add+0x308/0xe90 drivers/base/core.c:3343
device_create_groups_vargs drivers/base/core.c:4118 [inline]
device_create+0x26c/0x300 drivers/base/core.c:4160
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:642
configfs_mkdir+0x50a/0x9c0 fs/configfs/dir.c:1360
vfs_mkdir+0x38b/0x590 fs/namei.c:4073
do_mkdirat+0x174/0x4d0 fs/namei.c:4098
__do_sys_mkdirat fs/namei.c:4113 [inline]
__se_sys_mkdirat fs/namei.c:4111 [inline]
__x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4111
x64_sys_call+0x37e/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:259
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f0c51f781d9
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:00007f0c509d1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f0c521fffa0 RCX: 00007f0c51f781d9
RDX: 00000000000001ff RSI: 0000200000000240 RDI: ffffffffffffff9c
RBP: 00007f0c5200f888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0c52200038 R14: 00007f0c521fffa0 R15: 00007fffebc4e448
---[ end trace 4aa52aec415e5b2c ]---
kobject_add_internal failed for android_usb (error: -2 parent: )
------------[ cut here ]------------
kobject: '' (ffff88811c549000): is not initialized, yet kobject_put() is being called.
WARNING: CPU: 0 PID: 18316 at lib/kobject.c:760 kobject_put+0x8a/0x270 lib/kobject.c:758
Modules linked in:
CPU: 0 PID: 18316 Comm: syz.1.4693 Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
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 28 4a 39 ff 48 8b 33 48 c7 c7 e0 d4 64 85 48 89 da e8 56 9c 3b 02 <0f> 0b eb 0f e8 6d c9 f9 fe e9 7c 01 00 00 e8 63 c9 f9 fe 4c 8d 7b
RSP: 0018:ffffc90001567a08 EFLAGS: 00010246
RAX: ddd3885a73829400 RBX: ffff88811c549000 RCX: 0000000000080000
RDX: ffffc90002ddd000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90001567a30 R08: ffff8881f7032eff R09: 1ffff1103ee065df
R10: dffffc0000000000 R11: ffffed103ee065e0 R12: ffff8881553ec068
R13: ffff88811c54903c R14: 1ffff110238a9207 R15: 0000000000000000
FS: 00007f0c509d16c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f393fd5f5a0 CR3: 00000001265d0000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
put_device drivers/base/core.c:3530 [inline]
device_add+0x985/0xe90 drivers/base/core.c:3475
device_create_groups_vargs drivers/base/core.c:4118 [inline]
device_create+0x26c/0x300 drivers/base/core.c:4160
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:642
configfs_mkdir+0x50a/0x9c0 fs/configfs/dir.c:1360
vfs_mkdir+0x38b/0x590 fs/namei.c:4073
do_mkdirat+0x174/0x4d0 fs/namei.c:4098
__do_sys_mkdirat fs/namei.c:4113 [inline]
__se_sys_mkdirat fs/namei.c:4111 [inline]
__x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4111
x64_sys_call+0x37e/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:259
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f0c51f781d9
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:00007f0c509d1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f0c521fffa0 RCX: 00007f0c51f781d9
RDX: 00000000000001ff RSI: 0000200000000240 RDI: ffffffffffffff9c
RBP: 00007f0c5200f888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0c52200038 R14: 00007f0c521fffa0 R15: 00007fffebc4e448
---[ end trace 4aa52aec415e5b2d ]---