==================================================================
BUG: KASAN: use-after-free in kobject_get+0x113/0x120 lib/kobject.c:663
Read of size 1 at addr ffff88810f83803c by task syz.9.1117/4310
CPU: 1 PID: 4310 Comm: syz.9.1117 Tainted: G W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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:1329
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: 0033:0x7ff89fb63019
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:00007ff89e59b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007ff89fdeb090 RCX: 00007ff89fb63019
RDX: 00000000000001ff RSI: 00002000000003c0 RDI: ffffffffffffff9c
RBP: 00007ff89fbfa00c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff89fdeb128 R14: 00007ff89fdeb090 R15: 00007ffcda3aaef8
Allocated by task 290:
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_slab_alloc+0xb7/0xe0 mm/kasan/common.c:466
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]
kmem_cache_alloc+0xf7/0x260 mm/slub.c:3260
getname_flags+0xba/0x510 fs/namei.c:138
user_path_at_empty+0x2f/0x1c0 fs/namei.c:2890
user_path_at include/linux/namei.h:57 [inline]
ksys_umount fs/namespace.c:1787 [inline]
__do_sys_umount fs/namespace.c:1795 [inline]
__se_sys_umount fs/namespace.c:1793 [inline]
__x64_sys_umount+0xf9/0x170 fs/namespace.c:1793
x64_sys_call+0x8b7/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:167
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 290:
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]
kmem_cache_free+0x100/0x320 mm/slub.c:3544
putname fs/namei.c:271 [inline]
user_path_at_empty+0x162/0x1c0 fs/namei.c:2893
user_path_at include/linux/namei.h:57 [inline]
ksys_umount fs/namespace.c:1787 [inline]
__do_sys_umount fs/namespace.c:1795 [inline]
__se_sys_umount fs/namespace.c:1793 [inline]
__x64_sys_umount+0xf9/0x170 fs/namespace.c:1793
x64_sys_call+0x8b7/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:167
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
The buggy address belongs to the object at ffff88810f838000
which belongs to the cache names_cache of size 4096
The buggy address is located 60 bytes inside of
4096-byte region [ffff88810f838000, ffff88810f839000)
The buggy address belongs to the page:
page:ffffea00043e0e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10f838
head:ffffea00043e0e00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head|zone=1)
raw: 4000000000010200 0000000000000000 dead000000000122 ffff8881001c4f00
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 3822, ts 153351497224, free_ts 153237561533
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]
kmem_cache_alloc+0x138/0x260 mm/slub.c:3260
getname_flags+0xba/0x510 fs/namei.c:138
getname fs/namei.c:217 [inline]
__do_sys_rename fs/namei.c:5039 [inline]
__se_sys_rename fs/namei.c:5037 [inline]
__x64_sys_rename+0x5f/0x90 fs/namei.c:5037
x64_sys_call+0x680/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:83
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
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 mm/slub.c:2046 [inline]
__unfreeze_partials+0x15a/0x190 mm/slub.c:2532
put_cpu_partial+0xc6/0x120 mm/slub.c:2612
__slab_free+0x1d4/0x290 mm/slub.c:3395
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]
kmem_cache_alloc+0xf7/0x260 mm/slub.c:3260
getname_flags+0xba/0x510 fs/namei.c:138
user_path_at_empty+0x2f/0x1c0 fs/namei.c:2890
Memory state around the buggy address:
ffff88810f837f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88810f837f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88810f838000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88810f838080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88810f838100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
------------[ cut here ]------------
kobject: '' (ffff88810f838000): is not initialized, yet kobject_get() is being called.
WARNING: CPU: 1 PID: 4310 at lib/kobject.c:666 kobject_get+0x7c/0x120 lib/kobject.c:664
Modules linked in:
CPU: 1 PID: 4310 Comm: syz.9.1117 Tainted: G B W 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: f9 fe 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 96 44 39 ff 48 8b 33 48 c7 c7 60 c2 64 85 48 89 da e8 74 9c 3a 02 <0f> 0b eb 0c e8 0b d5 f9 fe eb 4c e8 04 d5 f9 fe 4c 8d 73 38 4c 89
RSP: 0018:ffffc90000c5fa18 EFLAGS: 00010246
RAX: 1210eae14bd69e00 RBX: ffff88810f838000 RCX: 0000000000080000
RDX: ffffc9000c983000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90000c5fa30 R08: ffffc90000c5f487 R09: 1ffff9200018be90
R10: dffffc0000000000 R11: fffff5200018be91 R12: 1ffff1102172310e
R13: dffffc0000000000 R14: 0000000000000000 R15: dffffc0000000000
FS: 00007ff89e59b6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff89e59aff8 CR3: 000000011d02b000 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:1329
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: 0033:0x7ff89fb63019
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:00007ff89e59b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007ff89fdeb090 RCX: 00007ff89fb63019
RDX: 00000000000001ff RSI: 00002000000003c0 RDI: ffffffffffffff9c
RBP: 00007ff89fbfa00c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff89fdeb128 R14: 00007ff89fdeb090 R15: 00007ffcda3aaef8
---[ end trace 8f4e635d8aa44f80 ]---
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 4310 at lib/refcount.c:25 refcount_warn_saturate+0x104/0x1a0 lib/refcount.c:25
Modules linked in:
CPU: 1 PID: 4310 Comm: syz.9.1117 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 80 47 63 85 e8 c8 47 5a 02 0f 0b eb df e8 5f 80 19 ff c6 05 1b ea 95 04 01 48 c7 c7 c0 46 63 85 e8 ac 47 5a 02 <0f> 0b eb c3 e8 43 80 19 ff c6 05 00 ea 95 04 01 48 c7 c7 20 47 63
RSP: 0018:ffffc90000c5f9f8 EFLAGS: 00010246
RAX: 1210eae14bd69e00 RBX: 0000000000000002 RCX: 0000000000080000
RDX: ffffc9000c983000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90000c5fa08 R08: ffffc90000c5f467 R09: 1ffff9200018be8c
R10: dffffc0000000000 R11: fffff5200018be8d R12: 1ffff1102172310e
R13: dffffc0000000000 R14: 0000000000000002 R15: 0000000000000000
FS: 00007ff89e59b6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f8d553fe60 CR3: 000000011d02b000 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:1329
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: 0033:0x7ff89fb63019
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:00007ff89e59b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007ff89fdeb090 RCX: 00007ff89fb63019
RDX: 00000000000001ff RSI: 00002000000003c0 RDI: ffffffffffffff9c
RBP: 00007ff89fbfa00c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff89fdeb128 R14: 00007ff89fdeb090 R15: 00007ffcda3aaef8
---[ end trace 8f4e635d8aa44f81 ]---
------------[ cut here ]------------
kobject: '' (ffff88810f838000): is not initialized, yet kobject_get() is being called.
WARNING: CPU: 1 PID: 4310 at lib/kobject.c:666 kobject_get lib/kobject.c:664 [inline]
WARNING: CPU: 1 PID: 4310 at lib/kobject.c:666 kobject_add_internal+0x12e/0xde0 lib/kobject.c:248
Modules linked in:
CPU: 1 PID: 4310 Comm: syz.9.1117 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 15 2c 39 ff 49 8b 34 24 48 c7 c7 60 c2 64 85 4c 89 e2 e8 f2 83 3a 02 <0f> 0b e9 04 01 00 00 e8 86 bc f9 fe b8 fe ff ff ff e9 b0 09 00 00
RSP: 0018:ffffc90000c5f898 EFLAGS: 00010246
RAX: 1210eae14bd69e00 RBX: ffff8881081a4500 RCX: 0000000000080000
RDX: ffffc9000c983000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90000c5f8f0 R08: ffff8881f7132f3f R09: 1ffff1103ee265e7
R10: dffffc0000000000 R11: ffffed103ee265e8 R12: ffff88810f838000
R13: ffff8881081a4518 R14: 0000000000000000 R15: 1ffff110210348a0
FS: 00007ff89e59b6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f8d553fe60 CR3: 000000011d02b000 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:1329
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: 0033:0x7ff89fb63019
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:00007ff89e59b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007ff89fdeb090 RCX: 00007ff89fb63019
RDX: 00000000000001ff RSI: 00002000000003c0 RDI: ffffffffffffff9c
RBP: 00007ff89fbfa00c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff89fdeb128 R14: 00007ff89fdeb090 R15: 00007ffcda3aaef8
---[ end trace 8f4e635d8aa44f82 ]---
------------[ cut here ]------------
refcount_t: saturated; leaking memory.
WARNING: CPU: 1 PID: 4310 at lib/refcount.c:22 refcount_warn_saturate+0x158/0x1a0 lib/refcount.c:22
Modules linked in:
CPU: 1 PID: 4310 Comm: syz.9.1117 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 60 46 63 85 e8 74 47 5a 02 0f 0b eb 8b e8 0b 80 19 ff c6 05 c6 e9 95 04 01 48 c7 c7 60 46 63 85 e8 58 47 5a 02 <0f> 0b e9 6c ff ff ff e8 ec 7f 19 ff c6 05 ab e9 95 04 01 48 c7 c7
RSP: 0018:ffffc90000c5f878 EFLAGS: 00010246
RAX: 1210eae14bd69e00 RBX: 0000000000000001 RCX: 0000000000080000
RDX: ffffc9000c983000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90000c5f888 R08: ffffc90000c5f2e7 R09: 1ffff9200018be5c
R10: dffffc0000000000 R11: fffff5200018be5d R12: 00000000c0000000
R13: ffff8881081a4518 R14: 0000000000000001 R15: ffff88810f838038
FS: 00007ff89e59b6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f8d553fe60 CR3: 000000011d02b000 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:1329
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: 0033:0x7ff89fb63019
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:00007ff89e59b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007ff89fdeb090 RCX: 00007ff89fb63019
RDX: 00000000000001ff RSI: 00002000000003c0 RDI: ffffffffffffff9c
RBP: 00007ff89fbfa00c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff89fdeb128 R14: 00007ff89fdeb090 R15: 00007ffcda3aaef8
---[ end trace 8f4e635d8aa44f83 ]---
------------[ cut here ]------------
kobject: '' (ffff88810f838000): is not initialized, yet kobject_put() is being called.
WARNING: CPU: 1 PID: 4310 at lib/kobject.c:760 kobject_put+0x8a/0x270 lib/kobject.c:758
Modules linked in:
CPU: 1 PID: 4310 Comm: syz.9.1117 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 68 43 39 ff 48 8b 33 48 c7 c7 e0 c2 64 85 48 89 da e8 46 9b 3a 02 <0f> 0b eb 0f e8 dd d3 f9 fe e9 7c 01 00 00 e8 d3 d3 f9 fe 4c 8d 7b
RSP: 0018:ffffc90000c5f860 EFLAGS: 00010246
RAX: 1210eae14bd69e00 RBX: ffff88810f838000 RCX: 0000000000080000
RDX: ffffc9000c983000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90000c5f888 R08: ffff8881f7132f3f R09: 1ffff1103ee265e7
R10: dffffc0000000000 R11: ffffed103ee265e8 R12: ffff88810f838000
R13: ffff88810f83803c R14: 1ffff11021f07007 R15: 0000000000000000
FS: 00007ff89e59b6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f8d553fe60 CR3: 000000011d02b000 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:1329
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: 0033:0x7ff89fb63019
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:00007ff89e59b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007ff89fdeb090 RCX: 00007ff89fb63019
RDX: 00000000000001ff RSI: 00002000000003c0 RDI: ffffffffffffff9c
RBP: 00007ff89fbfa00c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff89fdeb128 R14: 00007ff89fdeb090 R15: 00007ffcda3aaef8
---[ end trace 8f4e635d8aa44f84 ]---
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 1 PID: 4310 at lib/refcount.c:28 refcount_warn_saturate+0x120/0x1a0 lib/refcount.c:28
Modules linked in:
CPU: 1 PID: 4310 Comm: syz.9.1117 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 c0 46 63 85 e8 ac 47 5a 02 0f 0b eb c3 e8 43 80 19 ff c6 05 00 ea 95 04 01 48 c7 c7 20 47 63 85 e8 90 47 5a 02 <0f> 0b eb a7 e8 27 80 19 ff c6 05 e1 e9 95 04 01 48 c7 c7 60 46 63
RSP: 0018:ffffc90000c5f840 EFLAGS: 00010246
RAX: 1210eae14bd69e00 RBX: 0000000000000003 RCX: 0000000000080000
RDX: ffffc9000c983000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90000c5f850 R08: ffff8881f7132f3f R09: 1ffff1103ee265e7
R10: dffffc0000000000 R11: ffffed103ee265e8 R12: 00000000c0000000
R13: ffff88810f83803c R14: 0000000000000003 R15: ffff88810f838038
FS: 00007ff89e59b6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f8d553fe60 CR3: 000000011d02b000 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: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:1329
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: 0033:0x7ff89fb63019
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:00007ff89e59b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007ff89fdeb090 RCX: 00007ff89fb63019
RDX: 00000000000001ff RSI: 00002000000003c0 RDI: ffffffffffffff9c
RBP: 00007ff89fbfa00c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff89fdeb128 R14: 00007ff89fdeb090 R15: 00007ffcda3aaef8
---[ end trace 8f4e635d8aa44f85 ]---
kobject_add_internal failed for android_usb (error: -2 parent: )
------------[ cut here ]------------
kobject: '' (ffff88810f838000): is not initialized, yet kobject_put() is being called.
WARNING: CPU: 1 PID: 4310 at lib/kobject.c:760 kobject_put+0x8a/0x270 lib/kobject.c:758
Modules linked in:
CPU: 1 PID: 4310 Comm: syz.9.1117 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 68 43 39 ff 48 8b 33 48 c7 c7 e0 c2 64 85 48 89 da e8 46 9b 3a 02 <0f> 0b eb 0f e8 dd d3 f9 fe e9 7c 01 00 00 e8 d3 d3 f9 fe 4c 8d 7b
RSP: 0018:ffffc90000c5fa08 EFLAGS: 00010246
RAX: 1210eae14bd69e00 RBX: ffff88810f838000 RCX: 0000000000080000
RDX: ffffc9000c983000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90000c5fa30 R08: ffff8881f7132f3f R09: 1ffff1103ee265e7
R10: dffffc0000000000 R11: ffffed103ee265e8 R12: ffff88810b918868
R13: ffff88810f83803c R14: 1ffff11021f07007 R15: 0000000000000000
FS: 00007ff89e59b6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f8d553fe60 CR3: 000000011d02b000 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:1329
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: 0033:0x7ff89fb63019
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:00007ff89e59b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007ff89fdeb090 RCX: 00007ff89fb63019
RDX: 00000000000001ff RSI: 00002000000003c0 RDI: ffffffffffffff9c
RBP: 00007ff89fbfa00c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff89fdeb128 R14: 00007ff89fdeb090 R15: 00007ffcda3aaef8
---[ end trace 8f4e635d8aa44f86 ]---