KASAN: use-after-free Read in device_create

Status: upstream: reported C repro on 2026/07/30 16:16
Reported-by: syzbot+1573af6fa2e41a961e8e@syzkaller.appspotmail.com
First crash: 9d00h, last: 1d11h
▶ ▼ Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-6-1 KASAN: use-after-free Read in device_create 19 6 9d01h 14d 0/2 premoderation: reported on 2026/07/25 07:17
android-5-10 KASAN: use-after-free Read in device_create 19 syz, C 38 8h17m 5d15h 0/2 upstream: reported C repro on 2026/08/02 20:17

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in kobject_get+0x113/0x120 lib/kobject.c:663
Read of size 1 at addr ffff88811bc9983c by task syz-executor611/338

CPU: 1 PID: 338 Comm: syz-executor611 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 __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: 0033:0x7f21d96eb639
Code: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 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 d8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd92e0a9b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 0031672f74656764 RCX: 00007f21d96eb639
RDX: 00000000000001ff RSI: 00002000000003c0 RDI: 00000000ffffff9c
RBP: 00000000000f4240 R08: 0000000000000009 R09: 0000000000000009
R10: 0000000000000009 R11: 0000000000000246 R12: 0000000000006e74
R13: 00007ffd92e0a9cc R14: 00007ffd92e0a9e0 R15: 00007ffd92e0a9d0
 </TASK>

Allocated by task 308:
 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]
 device_create_groups_vargs drivers/base/core.c:4100 [inline]
 device_create+0x13a/0x300 drivers/base/core.c:4160
 android_device_create drivers/usb/gadget/configfs.c:1788 [inline]
 gadgets_make+0x816/0xa70 drivers/usb/gadget/configfs.c:1885
 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

Freed by task 310:
 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
 device_create_release+0x15/0x20 drivers/base/core.c:4085
 device_release+0x96/0x1c0 drivers/base/core.c:-1
 kobject_cleanup lib/kobject.c:713 [inline]
 kobject_release lib/kobject.c:744 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x18a/0x270 lib/kobject.c:761
 put_device drivers/base/core.c:3530 [inline]
 device_unregister drivers/base/core.c:3656 [inline]
 device_destroy+0xb4/0xf0 drivers/base/core.c:4226
 android_device_destroy drivers/usb/gadget/configfs.c:1820 [inline]
 gadgets_drop+0xa0/0xd0 drivers/usb/gadget/configfs.c:1901
 client_drop_item fs/configfs/dir.c:933 [inline]
 configfs_rmdir+0x871/0x960 fs/configfs/dir.c:1536
 vfs_rmdir+0x1ae/0x450 fs/namei.c:4157
 do_rmdir+0x261/0x6b0 fs/namei.c:4218
 __do_sys_rmdir fs/namei.c:4237 [inline]
 __se_sys_rmdir fs/namei.c:4235 [inline]
 __x64_sys_rmdir+0x49/0x50 fs/namei.c:4235
 x64_sys_call+0x25f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:85
 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 ffff88811bc99800
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 60 bytes inside of
 1024-byte region [ffff88811bc99800, ffff88811bc99c00)
The buggy address belongs to the page:
page:ffffea00046f2600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11bc98
head:ffffea00046f2600 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head|zone=1)
raw: 4000000000010200 0000000000000000 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 0xd2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 308, ts 28067262758, free_ts 28065949160
 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
 __napi_alloc_skb+0x162/0x2e0 net/core/skbuff.c:569
 napi_alloc_skb include/linux/skbuff.h:3102 [inline]
 page_to_skb+0x274/0xb60 drivers/net/virtio_net.c:474
 receive_mergeable drivers/net/virtio_net.c:1102 [inline]
 receive_buf+0xcd3/0x4bc0 drivers/net/virtio_net.c:1212
 virtnet_receive drivers/net/virtio_net.c:1504 [inline]
 virtnet_poll+0x510/0xe90 drivers/net/virtio_net.c:1617
 __napi_poll+0xbb/0x580 net/core/dev.c:7109
 napi_poll net/core/dev.c:7176 [inline]
 net_rx_action+0x37f/0x910 net/core/dev.c:7266
 handle_softirqs+0x250/0x560 kernel/softirq.c:583
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_compound_page+0x78/0xa0 mm/page_alloc.c:828
 destroy_compound_page include/linux/mm.h:1000 [inline]
 __put_compound_page+0x77/0xb0 mm/swap.c:111
 __put_page+0xbc/0xe0 mm/swap.c:127
 put_page include/linux/mm.h:1306 [inline]
 page_to_skb+0x755/0xb60 drivers/net/virtio_net.c:529
 receive_mergeable drivers/net/virtio_net.c:1102 [inline]
 receive_buf+0xcd3/0x4bc0 drivers/net/virtio_net.c:1212
 virtnet_receive drivers/net/virtio_net.c:1504 [inline]
 virtnet_poll+0x510/0xe90 drivers/net/virtio_net.c:1617
 __napi_poll+0xbb/0x580 net/core/dev.c:7109
 napi_poll net/core/dev.c:7176 [inline]
 net_rx_action+0x37f/0x910 net/core/dev.c:7266
 handle_softirqs+0x250/0x560 kernel/softirq.c:583
 __do_softirq kernel/softirq.c:621 [inline]
 invoke_softirq kernel/softirq.c:443 [inline]
 __irq_exit_rcu+0x52/0xf0 kernel/softirq.c:670
 irq_exit_rcu+0x9/0x10 kernel/softirq.c:682
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa9/0xc0 arch/x86/kernel/apic/apic.c:1108
 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:676

Memory state around the buggy address:
 ffff88811bc99700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88811bc99780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88811bc99800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                        ^
 ffff88811bc99880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88811bc99900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 338 at lib/refcount.c:25 refcount_warn_saturate+0x104/0x1a0 lib/refcount.c:25
Modules linked in:
CPU: 0 PID: 338 Comm: syz-executor611 Tainted: G    B             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 00 48 63 85 e8 c8 67 5a 02 0f 0b eb df e8 5f 80 19 ff c6 05 1b f5 95 04 01 48 c7 c7 40 47 63 85 e8 ac 67 5a 02 <0f> 0b eb c3 e8 43 80 19 ff c6 05 00 f5 95 04 01 48 c7 c7 a0 47 63
RSP: 0018:ffffc90000be79f8 EFLAGS: 00010246
RAX: 74e3183d55419200 RBX: 0000000000000002 RCX: ffff88810cb8a780
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc90000be7a08 R08: ffffc90000be7467 R09: 1ffff9200017ce8c
R10: dffffc0000000000 R11: fffff5200017ce8d R12: 1ffff11021ac8a0e
R13: dffffc0000000000 R14: 0000000000000002 R15: 0000000000000000
FS:  000055555a5843c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000040 CR3: 0000000123940000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __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: 0033:0x7f21d96eb639
Code: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 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 d8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd92e0a9b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 0031672f74656764 RCX: 00007f21d96eb639
RDX: 00000000000001ff RSI: 00002000000003c0 RDI: 00000000ffffff9c
RBP: 00000000000f4240 R08: 0000000000000009 R09: 0000000000000009
R10: 0000000000000009 R11: 0000000000000246 R12: 0000000000006e74
R13: 00007ffd92e0a9cc R14: 00007ffd92e0a9e0 R15: 00007ffd92e0a9d0
 </TASK>
---[ end trace 974d5a28880176bb ]---
------------[ cut here ]------------
refcount_t: saturated; leaking memory.
WARNING: CPU: 0 PID: 338 at lib/refcount.c:22 refcount_warn_saturate+0x158/0x1a0 lib/refcount.c:22
Modules linked in:
CPU: 0 PID: 338 Comm: syz-executor611 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 e0 46 63 85 e8 74 67 5a 02 0f 0b eb 8b e8 0b 80 19 ff c6 05 c6 f4 95 04 01 48 c7 c7 e0 46 63 85 e8 58 67 5a 02 <0f> 0b e9 6c ff ff ff e8 ec 7f 19 ff c6 05 ab f4 95 04 01 48 c7 c7
RSP: 0018:ffffc90000be78b8 EFLAGS: 00010246
RAX: 74e3183d55419200 RBX: 0000000000000001 RCX: ffff88810cb8a780
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc90000be78c8 R08: ffff8881f7032f3f R09: 1ffff1103ee065e7
R10: dffffc0000000000 R11: ffffed103ee065e8 R12: 00000000c0000000
R13: ffff88810d645018 R14: 0000000000000001 R15: ffff88811bc99838
FS:  000055555a5843c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000040 CR3: 0000000123940000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __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
 device_add+0x398/0xe90 drivers/base/core.c:3357
 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: 0033:0x7f21d96eb639
Code: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 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 d8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd92e0a9b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 0031672f74656764 RCX: 00007f21d96eb639
RDX: 00000000000001ff RSI: 00002000000003c0 RDI: 00000000ffffff9c
RBP: 00000000000f4240 R08: 0000000000000009 R09: 0000000000000009
R10: 0000000000000009 R11: 0000000000000246 R12: 0000000000006e74
R13: 00007ffd92e0a9cc R14: 00007ffd92e0a9e0 R15: 00007ffd92e0a9d0
 </TASK>
---[ end trace 974d5a28880176bc ]---
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 338 at lib/refcount.c:28 refcount_warn_saturate+0x120/0x1a0 lib/refcount.c:28
Modules linked in:
CPU: 0 PID: 338 Comm: syz-executor611 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 40 47 63 85 e8 ac 67 5a 02 0f 0b eb c3 e8 43 80 19 ff c6 05 00 f5 95 04 01 48 c7 c7 a0 47 63 85 e8 90 67 5a 02 <0f> 0b eb a7 e8 27 80 19 ff c6 05 e1 f4 95 04 01 48 c7 c7 e0 46 63
RSP: 0018:ffffc90000be7880 EFLAGS: 00010246
RAX: 74e3183d55419200 RBX: 0000000000000003 RCX: ffff88810cb8a780
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc90000be7890 R08: ffffc90000be72e7 R09: 1ffff9200017ce5c
R10: dffffc0000000000 R11: fffff5200017ce5d R12: 00000000c0000000
R13: ffff88811bc9983c R14: 0000000000000003 R15: ffff88811bc99838
FS:  000055555a5843c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000040 CR3: 0000000123940000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __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
 device_add+0x398/0xe90 drivers/base/core.c:3357
 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: 0033:0x7f21d96eb639
Code: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 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 d8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd92e0a9b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 0031672f74656764 RCX: 00007f21d96eb639
RDX: 00000000000001ff RSI: 00002000000003c0 RDI: 00000000ffffff9c
RBP: 00000000000f4240 R08: 0000000000000009 R09: 0000000000000009
R10: 0000000000000009 R11: 0000000000000246 R12: 0000000000006e74
R13: 00007ffd92e0a9cc R14: 00007ffd92e0a9e0 R15: 00007ffd92e0a9d0
 </TASK>
---[ end trace 974d5a28880176bd ]---
kobject_add_internal failed for f_midi (error: -2 parent: `6)

Crashes (10):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/05 07:02 android13-5.15-lts b885b84af7a2 52aa2820 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in device_create
2026/07/30 16:04 android13-5.15-lts 61d896ee2a80 2377cd3d .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in device_create
2026/08/07 00:40 android13-5.15-lts b885b84af7a2 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in device_create
2026/08/05 02:39 android13-5.15-lts b885b84af7a2 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in device_create
2026/08/04 08:59 android13-5.15-lts b885b84af7a2 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in device_create
2026/08/02 16:37 android13-5.15-lts 61d896ee2a80 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in device_create
2026/08/02 02:12 android13-5.15-lts 61d896ee2a80 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in device_create
2026/07/30 10:53 android13-5.15-lts 61d896ee2a80 2377cd3d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in device_create
2026/08/06 23:53 android13-5.15-lts b885b84af7a2 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in device_create
2026/08/03 04:55 android13-5.15-lts 61d896ee2a80 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in device_create
* Struck through repros no longer work on HEAD.