kobject: kobject_add_internal failed for hci6:201 with -EEXIST, don't try to register things with the same name in the same directory.
Bluetooth: hci6: failed to register connection device
==================================================================
BUG: KASAN: slab-use-after-free in l2cap_conn_ready net/bluetooth/l2cap_core.c:1623 [inline]
BUG: KASAN: slab-use-after-free in l2cap_connect_cfm+0xdb9/0xf80 net/bluetooth/l2cap_core.c:7304
Read of size 8 at addr ffff888079ea7480 by task kworker/u9:1/29955
CPU: 1 UID: 0 PID: 29955 Comm: kworker/u9:1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: hci6 hci_rx_work
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xcd/0x630 mm/kasan/report.c:482
kasan_report+0xe0/0x110 mm/kasan/report.c:595
l2cap_conn_ready net/bluetooth/l2cap_core.c:1623 [inline]
l2cap_connect_cfm+0xdb9/0xf80 net/bluetooth/l2cap_core.c:7304
hci_connect_cfm include/net/bluetooth/hci_core.h:2082 [inline]
le_conn_complete_evt+0x1665/0x1d70 net/bluetooth/hci_event.c:5771
hci_le_conn_complete_evt+0x23c/0x370 net/bluetooth/hci_event.c:5797
hci_le_meta_evt+0x357/0x5e0 net/bluetooth/hci_event.c:7234
hci_event_func net/bluetooth/hci_event.c:7542 [inline]
hci_event_packet+0x685/0x11c0 net/bluetooth/hci_event.c:7599
hci_rx_work+0x2c5/0x16b0 net/bluetooth/hci_core.c:4071
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Allocated by task 29955:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:388 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:405
kmalloc_noprof include/linux/slab.h:905 [inline]
kzalloc_noprof include/linux/slab.h:1039 [inline]
l2cap_chan_create+0x44/0x920 net/bluetooth/l2cap_core.c:445
l2cap_sock_alloc.constprop.0+0xf5/0x1d0 net/bluetooth/l2cap_sock.c:1906
l2cap_sock_new_connection_cb+0x101/0x240 net/bluetooth/l2cap_sock.c:1485
l2cap_connect_cfm+0x4c7/0xf80 net/bluetooth/l2cap_core.c:7287
hci_connect_cfm include/net/bluetooth/hci_core.h:2082 [inline]
le_conn_complete_evt+0x1665/0x1d70 net/bluetooth/hci_event.c:5771
hci_le_conn_complete_evt+0x23c/0x370 net/bluetooth/hci_event.c:5797
hci_le_meta_evt+0x357/0x5e0 net/bluetooth/hci_event.c:7234
hci_event_func net/bluetooth/hci_event.c:7542 [inline]
hci_event_packet+0x685/0x11c0 net/bluetooth/hci_event.c:7599
hci_rx_work+0x2c5/0x16b0 net/bluetooth/hci_core.c:4071
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Freed by task 30748:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:243 [inline]
__kasan_slab_free+0x60/0x70 mm/kasan/common.c:275
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2422 [inline]
slab_free mm/slub.c:4695 [inline]
kfree+0x2b4/0x4d0 mm/slub.c:4894
l2cap_chan_destroy net/bluetooth/l2cap_core.c:491 [inline]
kref_put include/linux/kref.h:65 [inline]
l2cap_chan_put+0x216/0x2c0 net/bluetooth/l2cap_core.c:515
l2cap_sock_cleanup_listen+0x4d/0x2a0 net/bluetooth/l2cap_sock.c:1468
l2cap_sock_release+0x69/0x250 net/bluetooth/l2cap_sock.c:1426
__sock_release+0xb3/0x270 net/socket.c:649
sock_close+0x1c/0x30 net/socket.c:1439
__fput+0x402/0xb70 fs/file_table.c:468
task_work_run+0x150/0x240 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x86f/0x2bf0 kernel/exit.c:961
do_group_exit+0xd3/0x2a0 kernel/exit.c:1102
get_signal+0x2673/0x26d0 kernel/signal.c:3034
arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x41c/0x4e0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff888079ea7000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1152 bytes inside of
freed 2048-byte region [ffff888079ea7000, ffff888079ea7800)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x79ea0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801b842000 0000000000000000 dead000000000001
raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b842000 0000000000000000 dead000000000001
head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0001e7a801 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
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 26789, tgid 26789 (syz-executor), ts 2838091136841, free_ts 2838015426519
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851
prep_new_page mm/page_alloc.c:1859 [inline]
get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858
__alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:5148
alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416
alloc_slab_page mm/slub.c:2492 [inline]
allocate_slab mm/slub.c:2660 [inline]
new_slab+0x247/0x330 mm/slub.c:2714
___slab_alloc+0xcf2/0x1750 mm/slub.c:3901
__slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3992
__slab_alloc_node mm/slub.c:4067 [inline]
slab_alloc_node mm/slub.c:4228 [inline]
__kmalloc_cache_noprof+0xfb/0x3e0 mm/slub.c:4402
kmalloc_noprof include/linux/slab.h:905 [inline]
rtnl_newlink+0x11b/0x2000 net/core/rtnetlink.c:3957
rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6946
netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552
netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896
sock_sendmsg_nosec net/socket.c:714 [inline]
__sock_sendmsg net/socket.c:729 [inline]
__sys_sendto+0x4a3/0x520 net/socket.c:2228
__do_sys_sendto net/socket.c:2235 [inline]
__se_sys_sendto net/socket.c:2231 [inline]
__x64_sys_sendto+0xe0/0x1c0 net/socket.c:2231
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
page last free pid 26829 tgid 26829 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1395 [inline]
__free_frozen_pages+0x7d5/0x10f0 mm/page_alloc.c:2895
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:340
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4191 [inline]
slab_alloc_node mm/slub.c:4240 [inline]
__kmalloc_cache_noprof+0x1f1/0x3e0 mm/slub.c:4402
kmalloc_noprof include/linux/slab.h:905 [inline]
kzalloc_noprof include/linux/slab.h:1039 [inline]
ipv6_add_addr+0x4e3/0x1fe0 net/ipv6/addrconf.c:1120
add_addr+0xde/0x350 net/ipv6/addrconf.c:3201
add_v4_addrs+0x642/0x980 net/ipv6/addrconf.c:3263
addrconf_gre_config net/ipv6/addrconf.c:3545 [inline]
addrconf_init_auto_addrs+0x51a/0x810 net/ipv6/addrconf.c:3559
addrconf_notify+0xe93/0x19e0 net/ipv6/addrconf.c:3740
notifier_call_chain+0xbc/0x410 kernel/notifier.c:85
call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2229
call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
call_netdevice_notifiers net/core/dev.c:2281 [inline]
__dev_notify_flags+0x12c/0x2e0 net/core/dev.c:9588
netif_change_flags+0x108/0x160 net/core/dev.c:9617
do_setlink.constprop.0+0xb53/0x4380 net/core/rtnetlink.c:3143
rtnl_changelink net/core/rtnetlink.c:3761 [inline]
__rtnl_newlink net/core/rtnetlink.c:3920 [inline]
rtnl_newlink+0x1446/0x2000 net/core/rtnetlink.c:4057
Memory state around the buggy address:
ffff888079ea7380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888079ea7400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888079ea7480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888079ea7500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888079ea7580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
==================================================================
BUG: KASAN: wild-memory-access in instrument_atomic_read include/linux/instrumented.h:68 [inline]
BUG: KASAN: wild-memory-access in atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
BUG: KASAN: wild-memory-access in l2cap_chan_lock include/net/bluetooth/l2cap.h:827 [inline]
BUG: KASAN: wild-memory-access in l2cap_conn_ready net/bluetooth/l2cap_core.c:1625 [inline]
BUG: KASAN: wild-memory-access in l2cap_connect_cfm+0x7e6/0xf80 net/bluetooth/l2cap_core.c:7304
Read of size 4 at addr deacfffffffffc8c by task kworker/u9:1/29955
CPU: 1 UID: 0 PID: 29955 Comm: kworker/u9:1 Tainted: G B syzkaller #0 PREEMPT(full)
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: hci6 hci_rx_work
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
kasan_report+0xe0/0x110 mm/kasan/report.c:595
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0x100/0x1b0 mm/kasan/generic.c:189
instrument_atomic_read include/linux/instrumented.h:68 [inline]
atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
l2cap_chan_lock include/net/bluetooth/l2cap.h:827 [inline]
l2cap_conn_ready net/bluetooth/l2cap_core.c:1625 [inline]
l2cap_connect_cfm+0x7e6/0xf80 net/bluetooth/l2cap_core.c:7304
hci_connect_cfm include/net/bluetooth/hci_core.h:2082 [inline]
le_conn_complete_evt+0x1665/0x1d70 net/bluetooth/hci_event.c:5771
hci_le_conn_complete_evt+0x23c/0x370 net/bluetooth/hci_event.c:5797
hci_le_meta_evt+0x357/0x5e0 net/bluetooth/hci_event.c:7234
hci_event_func net/bluetooth/hci_event.c:7542 [inline]
hci_event_packet+0x685/0x11c0 net/bluetooth/hci_event.c:7599
hci_rx_work+0x2c5/0x16b0 net/bluetooth/hci_core.c:4071
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
==================================================================
Oops: general protection fault, probably for non-canonical address 0xfbd59bffffffff91: 0000 [#1] SMP KASAN NOPTI
KASAN: maybe wild-memory-access in range [0xdeacfffffffffc88-0xdeacfffffffffc8f]
CPU: 1 UID: 0 PID: 29955 Comm: kworker/u9:1 Tainted: G B syzkaller #0 PREEMPT(full)
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: hci6 hci_rx_work
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline]
RIP: 0010:l2cap_chan_lock include/net/bluetooth/l2cap.h:827 [inline]
RIP: 0010:l2cap_conn_ready net/bluetooth/l2cap_core.c:1625 [inline]
RIP: 0010:l2cap_connect_cfm+0x7ed/0xf80 net/bluetooth/l2cap_core.c:7304
Code: 80 fb ff ff 49 39 c5 0f 84 29 01 00 00 e8 4b 68 25 f7 49 8d 6f 0c be 04 00 00 00 48 89 ef e8 aa e2 8a f7 48 89 e8 48 c1 e8 03 <0f> b6 14 18 48 89 e8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 c5
RSP: 0018:ffffc900046f7818 EFLAGS: 00010213
RAX: 1bd59fffffffff91 RBX: dffffc0000000000 RCX: ffffc9001ba87000
RDX: 0000000000100000 RSI: ffffffff8220e747 RDI: 0000000000000007
RBP: deacfffffffffc8c R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 3d3d3d3d3d3d3d3d R12: ffff88806504c03d
R13: ffff888060c30ac0 R14: 0000000000000080 R15: deacfffffffffc80
FS: 0000000000000000(0000) GS:ffff8881247b3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055559074d808 CR3: 0000000053624000 CR4: 0000000000350ef0
Call Trace:
hci_connect_cfm include/net/bluetooth/hci_core.h:2082 [inline]
le_conn_complete_evt+0x1665/0x1d70 net/bluetooth/hci_event.c:5771
hci_le_conn_complete_evt+0x23c/0x370 net/bluetooth/hci_event.c:5797
hci_le_meta_evt+0x357/0x5e0 net/bluetooth/hci_event.c:7234
hci_event_func net/bluetooth/hci_event.c:7542 [inline]
hci_event_packet+0x685/0x11c0 net/bluetooth/hci_event.c:7599
hci_rx_work+0x2c5/0x16b0 net/bluetooth/hci_core.c:4071
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline]
RIP: 0010:l2cap_chan_lock include/net/bluetooth/l2cap.h:827 [inline]
RIP: 0010:l2cap_conn_ready net/bluetooth/l2cap_core.c:1625 [inline]
RIP: 0010:l2cap_connect_cfm+0x7ed/0xf80 net/bluetooth/l2cap_core.c:7304
Code: 80 fb ff ff 49 39 c5 0f 84 29 01 00 00 e8 4b 68 25 f7 49 8d 6f 0c be 04 00 00 00 48 89 ef e8 aa e2 8a f7 48 89 e8 48 c1 e8 03 <0f> b6 14 18 48 89 e8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 c5
RSP: 0018:ffffc900046f7818 EFLAGS: 00010213
RAX: 1bd59fffffffff91 RBX: dffffc0000000000 RCX: ffffc9001ba87000
RDX: 0000000000100000 RSI: ffffffff8220e747 RDI: 0000000000000007
RBP: deacfffffffffc8c R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 3d3d3d3d3d3d3d3d R12: ffff88806504c03d
R13: ffff888060c30ac0 R14: 0000000000000080 R15: deacfffffffffc80
FS: 0000000000000000(0000) GS:ffff8881246b3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000003e00d000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess), 4 bytes skipped:
0: 49 39 c5 cmp %rax,%r13
3: 0f 84 29 01 00 00 je 0x132
9: e8 4b 68 25 f7 call 0xf7256859
e: 49 8d 6f 0c lea 0xc(%r15),%rbp
12: be 04 00 00 00 mov $0x4,%esi
17: 48 89 ef mov %rbp,%rdi
1a: e8 aa e2 8a f7 call 0xf78ae2c9
1f: 48 89 e8 mov %rbp,%rax
22: 48 c1 e8 03 shr $0x3,%rax
* 26: 0f b6 14 18 movzbl (%rax,%rbx,1),%edx <-- trapping instruction
2a: 48 89 e8 mov %rbp,%rax
2d: 83 e0 07 and $0x7,%eax
30: 83 c0 03 add $0x3,%eax
33: 38 d0 cmp %dl,%al
35: 7c 08 jl 0x3f
37: 84 d2 test %dl,%dl
39: 0f .byte 0xf
3a: 85 c5 test %eax,%ebp