==================================================================
BUG: KASAN: use-after-free in kobject_get+0x113/0x120 lib/kobject.c:663
Read of size 1 at addr ffff88811918a03c by task syz.1.352/1281
CPU: 0 PID: 1281 Comm: syz.1.352 Not tainted 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: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: 0033:0x7fb019220159
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:00007fb017c79028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fb0194a7fa0 RCX: 00007fb019220159
RDX: 00000000000001ff RSI: 0000200000000100 RDI: ffffffffffffff9c
RBP: 00007fb0192b706b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb0194a8038 R14: 00007fb0194a7fa0 R15: 00007ffdddc36d48
Allocated by task 1008:
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]
nlmsg_new include/net/netlink.h:953 [inline]
inet6_rt_notify+0x293/0x480 net/ipv6/route.c:6175
fib6_add_rt2node net/ipv6/ip6_fib.c:1255 [inline]
fib6_add+0x223f/0x3d70 net/ipv6/ip6_fib.c:1484
__ip6_ins_rt net/ipv6/route.c:1309 [inline]
ip6_ins_rt+0xd3/0x130 net/ipv6/route.c:1319
__ipv6_ifa_notify+0x4df/0xe70 net/ipv6/addrconf.c:6218
ipv6_ifa_notify net/ipv6/addrconf.c:6257 [inline]
add_addr+0x1a5/0x280 net/ipv6/addrconf.c:3170
add_v4_addrs+0x653/0xb20 net/ipv6/addrconf.c:3226
addrconf_gre_config net/ipv6/addrconf.c:3504 [inline]
addrconf_init_auto_addrs+0x8da/0xbd0 net/ipv6/addrconf.c:3519
addrconf_notify+0x95d/0xe00 net/ipv6/addrconf.c:3696
notifier_call_chain kernel/notifier.c:83 [inline]
raw_notifier_call_chain+0x90/0x100 kernel/notifier.c:391
call_netdevice_notifiers_info net/core/dev.c:2070 [inline]
call_netdevice_notifiers_extack net/core/dev.c:2082 [inline]
call_netdevice_notifiers net/core/dev.c:2096 [inline]
__dev_notify_flags+0x2f4/0x5b0 net/core/dev.c:8925
dev_change_flags+0xe3/0x1a0 net/core/dev.c:8963
do_setlink+0xc95/0x2970 net/core/rtnetlink.c:2791
__rtnl_newlink net/core/rtnetlink.c:3462 [inline]
rtnl_newlink+0x1598/0x1900 net/core/rtnetlink.c:3584
rtnetlink_rcv_msg+0x9fd/0xcb0 net/core/rtnetlink.c:5662
netlink_rcv_skb+0x1e9/0x430 net/netlink/af_netlink.c:2520
rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5680
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x86c/0xa30 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x879/0xb80 net/netlink/af_netlink.c:1923
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
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 ffff88811918a000
which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 60 bytes inside of
1024-byte region [ffff88811918a000, ffff88811918a400)
The buggy address belongs to the page:
page:ffffea0004646200 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88811918f000 pfn:0x119188
head:ffffea0004646200 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head|zone=1)
raw: 4000000000010200 ffffea00042c6a08 ffffea00044d7408 ffff888100043080
raw: ffff88811918f000 0000000000100003 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 106, ts 6389003196, free_ts 0
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 include/linux/skbuff.h:1183 [inline]
netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline]
netlink_sendmsg+0x611/0xb80 net/netlink/af_netlink.c:1898
sock_sendmsg_nosec net/socket.c:704 [inline]
__sock_sendmsg net/socket.c:716 [inline]
____sys_sendmsg+0x5be/0x8f0 net/socket.c:2436
___sys_sendmsg+0x236/0x2e0 net/socket.c:2490
__sys_sendmsg net/socket.c:2519 [inline]
__do_sys_sendmsg net/socket.c:2528 [inline]
__se_sys_sendmsg net/socket.c:2526 [inline]
__x64_sys_sendmsg+0x201/0x2d0 net/socket.c:2526
x64_sys_call+0x4b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:47
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_owner free stack trace missing
Memory state around the buggy address:
ffff888119189f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888119189f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88811918a000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88811918a080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88811918a100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
------------[ cut here ]------------
kobject: '' (ffff88811918a000): is not initialized, yet kobject_get() is being called.
WARNING: CPU: 1 PID: 1281 at lib/kobject.c:666 kobject_get+0x7c/0x120 lib/kobject.c:664
Modules linked in:
CPU: 1 PID: 1281 Comm: syz.1.352 Tainted: G B 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 a6 53 39 ff 48 8b 33 48 c7 c7 a0 cd 64 85 48 89 da e8 34 54 3b 02 <0f> 0b eb 0c e8 8b dd f9 fe eb 4c e8 84 dd f9 fe 4c 8d 73 38 4c 89
RSP: 0018:ffffc90000e2fa18 EFLAGS: 00010246
RAX: f777e84b9c989700 RBX: ffff88811918a000 RCX: 0000000000080000
RDX: ffffc90005f5c000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90000e2fa30 R08: ffff8881f7132f3f R09: 1ffff1103ee265e7
R10: dffffc0000000000 R11: ffffed103ee265e8 R12: 1ffff110243fe90e
R13: dffffc0000000000 R14: 0000000000000000 R15: dffffc0000000000
FS: 00007fb017c796c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb017c58d58 CR3: 000000012ae40000 CR4: 00000000003526a0
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: 0033:0x7fb019220159
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:00007fb017c79028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fb0194a7fa0 RCX: 00007fb019220159
RDX: 00000000000001ff RSI: 0000200000000100 RDI: ffffffffffffff9c
RBP: 00007fb0192b706b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb0194a8038 R14: 00007fb0194a7fa0 R15: 00007ffdddc36d48
---[ end trace 959af9177d4811de ]---
general protection fault, probably for non-canonical address 0xec27a5c9e92a886c: 0000 [#1] PREEMPT SMP KASAN
KASAN: maybe wild-memory-access in range [0x613d4e4f49544360-0x613d4e4f49544367]
CPU: 1 PID: 1281 Comm: syz.1.352 Tainted: G B W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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 7f 36 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 4f 36 39 ff 49 8b 04 24 48 85 c0 0f
RSP: 0018:ffffc90000e2f898 EFLAGS: 00010206
RAX: 0c27a9c9e92a886c RBX: ffff888128f73d00 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88811918a028
RBP: ffffc90000e2f8f0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520001c5f04 R12: 613d4e4f49544361
R13: ffff888128f73d18 R14: ffffffff86a49a00 R15: ffff88811918a000
FS: 00007fb017c796c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb017c58d58 CR3: 000000012ae40000 CR4: 00000000003526a0
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: 0033:0x7fb019220159
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:00007fb017c79028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fb0194a7fa0 RCX: 00007fb019220159
RDX: 00000000000001ff RSI: 0000200000000100 RDI: ffffffffffffff9c
RBP: 00007fb0192b706b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb0194a8038 R14: 00007fb0194a7fa0 R15: 00007ffdddc36d48
Modules linked in:
---[ end trace 959af9177d4811df ]---
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 7f 36 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 4f 36 39 ff 49 8b 04 24 48 85 c0 0f
RSP: 0018:ffffc90000e2f898 EFLAGS: 00010206
RAX: 0c27a9c9e92a886c RBX: ffff888128f73d00 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88811918a028
RBP: ffffc90000e2f8f0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520001c5f04 R12: 613d4e4f49544361
R13: ffff888128f73d18 R14: ffffffff86a49a00 R15: ffff88811918a000
FS: 00007fb017c796c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc4798f808 CR3: 000000012ae40000 CR4: 00000000003526a0
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 7f 36 39 ff call 0xff393687
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 4f 36 39 ff call 0xff393687
38: 49 8b 04 24 mov (%r12),%rax
3c: 48 85 c0 test %rax,%rax
3f: 0f .byte 0xf