==================================================================
BUG: KASAN: use-after-free in kobject_get+0x113/0x120 lib/kobject.c:663
Read of size 1 at addr ffff88810d68683c by task syz.3.2121/8171
CPU: 0 PID: 8171 Comm: syz.3.2121 Tainted: G W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
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:1356
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: 0033:0x7f8bf6606559
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:00007f8bf505e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f8bf688cfa0 RCX: 00007f8bf6606559
RDX: 00000000000001ff RSI: 0000200000000180 RDI: ffffffffffffff9c
RBP: 00007f8bf669db20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8bf688d038 R14: 00007f8bf688cfa0 R15: 00007ffef907b308
Allocated by task 8092:
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]
__kmalloc_track_caller+0x13c/0x2c0 mm/slub.c:4959
kmalloc_reserve net/core/skbuff.c:357 [inline]
__alloc_skb+0x210/0x730 net/core/skbuff.c:428
alloc_skb include/linux/skbuff.h:1183 [inline]
alloc_uevent_skb+0x85/0x240 lib/kobject_uevent.c:290
uevent_net_broadcast_untagged lib/kobject_uevent.c:326 [inline]
kobject_uevent_net_broadcast+0x335/0x5a0 lib/kobject_uevent.c:409
kobject_uevent_env+0x52b/0x700 lib/kobject_uevent.c:608
kobject_uevent+0x1d/0x30 lib/kobject_uevent.c:657
loop_configure+0x1354/0x1700 drivers/block/loop.c:1324
lo_ioctl+0x2eb/0x2350 drivers/block/loop.c:1856
blkdev_ioctl+0x2f3/0x660 block/ioctl.c:604
block_ioctl+0xaf/0x100 block/fops.c:496
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl+0x121/0x1a0 fs/ioctl.c:860
__x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:860
x64_sys_call+0x2f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:17
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 101:
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
skb_free_head net/core/skbuff.c:656 [inline]
skb_release_data+0x7bd/0xa20 net/core/skbuff.c:678
skb_release_all net/core/skbuff.c:743 [inline]
__kfree_skb net/core/skbuff.c:757 [inline]
consume_skb+0xab/0x1f0 net/core/skbuff.c:934
skb_free_datagram+0x28/0xe0 net/core/datagram.c:325
netlink_recvmsg+0x5dd/0xe40 net/netlink/af_netlink.c:2002
____sys_recvmsg+0x2ca/0x5b0 net/socket.c:-1
___sys_recvmsg+0x213/0x5c0 net/socket.c:2697
__sys_recvmsg net/socket.c:2727 [inline]
__do_sys_recvmsg net/socket.c:2737 [inline]
__se_sys_recvmsg net/socket.c:2734 [inline]
__x64_sys_recvmsg+0x1fe/0x2d0 net/socket.c:2734
x64_sys_call+0x705/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:48
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
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
qdisc_destroy+0x166/0x270 net/sched/sch_generic.c:1036
qdisc_put net/sched/sch_generic.c:1048 [inline]
shutdown_scheduler_queue net/sched/sch_generic.c:1101 [inline]
netdev_for_each_tx_queue include/linux/netdevice.h:2413 [inline]
dev_shutdown+0x198/0x580 net/sched/sch_generic.c:1409
unregister_netdevice_many+0x965/0x1a00 net/core/dev.c:11170
unregister_netdevice_queue+0x2e1/0x320 net/core/dev.c:11110
unregister_netdevice include/linux/netdevice.h:3059 [inline]
__tun_detach+0xc9d/0x1450 drivers/net/tun.c:686
tun_detach drivers/net/tun.c:702 [inline]
tun_chr_close+0x92/0x140 drivers/net/tun.c:3454
__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
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
qdisc_destroy+0x166/0x270 net/sched/sch_generic.c:1036
qdisc_put net/sched/sch_generic.c:1048 [inline]
shutdown_scheduler_queue net/sched/sch_generic.c:1101 [inline]
netdev_for_each_tx_queue include/linux/netdevice.h:2413 [inline]
dev_shutdown+0x198/0x580 net/sched/sch_generic.c:1409
unregister_netdevice_many+0x965/0x1a00 net/core/dev.c:11170
unregister_netdevice_queue+0x2e1/0x320 net/core/dev.c:11110
unregister_netdevice include/linux/netdevice.h:3059 [inline]
__tun_detach+0xc9d/0x1450 drivers/net/tun.c:686
tun_detach drivers/net/tun.c:702 [inline]
tun_chr_close+0x92/0x140 drivers/net/tun.c:3454
__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 ffff88810d686800
which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 60 bytes inside of
1024-byte region [ffff88810d686800, ffff88810d686c00)
The buggy address belongs to the page:
page:ffffea000435a000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10d680
head:ffffea000435a000 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head|zone=1)
raw: 4000000000010200 ffffea00042e7c00 0000000600000006 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 289, ts 140528279080, free_ts 140146855113
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2610
prep_new_page+0x1c/0x110 mm/page_alloc.c:2616
get_page_from_freelist+0x2d42/0x2dd0 mm/page_alloc.c:4492
__alloc_pages+0x1a2/0x460 mm/page_alloc.c:5829
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+0x16a/0x2c0 mm/slub.c:4432
__kmalloc_node include/linux/slab.h:487 [inline]
kmalloc_node include/linux/slab.h:642 [inline]
kvmalloc_node+0x211/0x320 mm/util.c:621
kvmalloc include/linux/mm.h:862 [inline]
xt_alloc_table_info+0x3b/0xa0 net/netfilter/x_tables.c:1215
do_replace net/ipv6/netfilter/ip6_tables.c:1148 [inline]
do_ip6t_set_ctl+0x865/0xd80 net/ipv6/netfilter/ip6_tables.c:1648
nf_setsockopt+0x272/0x2a0 net/netfilter/nf_sockopt.c:101
ipv6_setsockopt+0x258f/0x3750 net/ipv6/ipv6_sockglue.c:1011
tcp_setsockopt+0x22b/0x1e90 net/ipv4/tcp.c:3715
sock_common_setsockopt+0xa0/0xb0 net/core/sock.c:3475
__sys_setsockopt+0x2e9/0x470 net/socket.c:2203
page last free stack trace:
reset_page_owner include/linux/page_owner.h:26 [inline]
free_pages_prepare mm/page_alloc.c:1477 [inline]
free_pcp_prepare mm/page_alloc.c:1549 [inline]
free_unref_page_prepare+0x5fa/0x600 mm/page_alloc.c:3540
free_unref_page+0xae/0x540 mm/page_alloc.c:3622
free_the_page mm/page_alloc.c:808 [inline]
__free_pages+0x6c/0x100 mm/page_alloc.c:5905
__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
getname+0x19/0x20 fs/namei.c:217
Memory state around the buggy address:
ffff88810d686700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88810d686780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88810d686800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88810d686880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88810d686900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
general protection fault, probably for non-canonical address 0xecedc82d0c67a9cd: 0000 [#1] PREEMPT SMP KASAN
KASAN: maybe wild-memory-access in range [0x676e6168633d4e68-0x676e6168633d4e6f]
CPU: 1 PID: 8171 Comm: syz.3.2121 Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
RIP: 0010:kobj_child_ns_ops lib/kobject.c:1084 [inline]
RIP: 0010:kobj_ns_ops lib/kobject.c:1092 [inline]
RIP: 0010:kobject_namespace lib/kobject.c:30 [inline]
RIP: 0010:create_dir lib/kobject.c:89 [inline]
RIP: 0010:kobject_add_internal+0x5e3/0xde0 lib/kobject.c:263
Code: 4c 89 e7 e8 ff 24 39 ff 4d 8b 24 24 4d 85 e4 0f 84 db 00 00 00 49 83 c4 20 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 e7 e8 cf 24 39 ff 49 8b 04 24 48 85 c0 0f
RSP: 0018:ffffc90000de7898 EFLAGS: 00010203
RAX: 0cedcc2d0c67a9cd RBX: ffff8881073cf800 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88810d686828
RBP: ffffc90000de78f0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520001bcf04 R12: 676e6168633d4e6f
R13: ffff8881073cf818 R14: ffffffff86a49cc0 R15: ffff88810d686800
FS: 00007f8bf505e6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f53dac83ff8 CR3: 000000011ad66000 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:1356
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: 0033:0x7f8bf6606559
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:00007f8bf505e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f8bf688cfa0 RCX: 00007f8bf6606559
RDX: 00000000000001ff RSI: 0000200000000180 RDI: ffffffffffffff9c
RBP: 00007f8bf669db20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8bf688d038 R14: 00007f8bf688cfa0 R15: 00007ffef907b308
Modules linked in:
---[ end trace b9b9a1ee9ca6c79b ]---
RIP: 0010:kobj_child_ns_ops lib/kobject.c:1084 [inline]
RIP: 0010:kobj_ns_ops lib/kobject.c:1092 [inline]
RIP: 0010:kobject_namespace lib/kobject.c:30 [inline]
RIP: 0010:create_dir lib/kobject.c:89 [inline]
RIP: 0010:kobject_add_internal+0x5e3/0xde0 lib/kobject.c:263
Code: 4c 89 e7 e8 ff 24 39 ff 4d 8b 24 24 4d 85 e4 0f 84 db 00 00 00 49 83 c4 20 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 e7 e8 cf 24 39 ff 49 8b 04 24 48 85 c0 0f
RSP: 0018:ffffc90000de7898 EFLAGS: 00010203
RAX: 0cedcc2d0c67a9cd RBX: ffff8881073cf800 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88810d686828
RBP: ffffc90000de78f0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520001bcf04 R12: 676e6168633d4e6f
R13: ffff8881073cf818 R14: ffffffff86a49cc0 R15: ffff88810d686800
FS: 00007f8bf505e6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f53da842000 CR3: 000000011ad66000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 4c 89 e7 mov %r12,%rdi
3: e8 ff 24 39 ff call 0xff392507
8: 4d 8b 24 24 mov (%r12),%r12
c: 4d 85 e4 test %r12,%r12
f: 0f 84 db 00 00 00 je 0xf0
15: 49 83 c4 20 add $0x20,%r12
19: 4c 89 e0 mov %r12,%rax
1c: 48 c1 e8 03 shr $0x3,%rax
20: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx
27: fc ff df
* 2a: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) <-- trapping instruction
2e: 74 08 je 0x38
30: 4c 89 e7 mov %r12,%rdi
33: e8 cf 24 39 ff call 0xff392507
38: 49 8b 04 24 mov (%r12),%rax
3c: 48 85 c0 test %rax,%rax
3f: 0f .byte 0xf