ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
kobject: kobject_add_internal failed for hci4:201 with -EEXIST, don't try to register things with the same name in the same directory.
Bluetooth: hci4: failed to register connection device
==================================================================
BUG: KASAN: slab-use-after-free in l2cap_conn_ready net/bluetooth/l2cap_core.c:1616 [inline]
BUG: KASAN: slab-use-after-free in l2cap_connect_cfm+0xe57/0x1050 net/bluetooth/l2cap_core.c:7368
Read of size 8 at addr ffff8880568eb480 by task kworker/u9:1/26188
CPU: 1 UID: 0 PID: 26188 Comm: kworker/u9:1 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: hci4 hci_rx_work
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x156/0x4c9 mm/kasan/report.c:482
kasan_report+0xdf/0x1e0 mm/kasan/report.c:595
l2cap_conn_ready net/bluetooth/l2cap_core.c:1616 [inline]
l2cap_connect_cfm+0xe57/0x1050 net/bluetooth/l2cap_core.c:7368
hci_connect_cfm include/net/bluetooth/hci_core.h:2139 [inline]
le_conn_complete_evt+0x195c/0x1f40 net/bluetooth/hci_event.c:5847
hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5873
hci_le_meta_evt+0x34a/0x5f0 net/bluetooth/hci_event.c:7473
hci_event_func net/bluetooth/hci_event.c:7781 [inline]
hci_event_packet+0x682/0x11c0 net/bluetooth/hci_event.c:7838
hci_rx_work+0x451/0xfc0 net/bluetooth/hci_core.c:4077
process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275
process_scheduled_works kernel/workqueue.c:3358 [inline]
worker_thread+0x5da/0xe40 kernel/workqueue.c:3439
kthread+0x370/0x450 kernel/kthread.c:467
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Allocated by task 26188:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
kmalloc_noprof include/linux/slab.h:950 [inline]
kzalloc_noprof include/linux/slab.h:1188 [inline]
l2cap_chan_create+0x44/0x940 net/bluetooth/l2cap_core.c:445
l2cap_sock_alloc.constprop.0+0xf5/0x1e0 net/bluetooth/l2cap_sock.c:1931
l2cap_sock_new_connection_cb+0x101/0x260 net/bluetooth/l2cap_sock.c:1510
l2cap_connect_cfm+0x4e2/0x1050 net/bluetooth/l2cap_core.c:7351
hci_connect_cfm include/net/bluetooth/hci_core.h:2139 [inline]
le_conn_complete_evt+0x195c/0x1f40 net/bluetooth/hci_event.c:5847
hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5873
hci_le_meta_evt+0x34a/0x5f0 net/bluetooth/hci_event.c:7473
hci_event_func net/bluetooth/hci_event.c:7781 [inline]
hci_event_packet+0x682/0x11c0 net/bluetooth/hci_event.c:7838
hci_rx_work+0x451/0xfc0 net/bluetooth/hci_core.c:4077
process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275
process_scheduled_works kernel/workqueue.c:3358 [inline]
worker_thread+0x5da/0xe40 kernel/workqueue.c:3439
kthread+0x370/0x450 kernel/kthread.c:467
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Freed by task 10447:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2692 [inline]
slab_free mm/slub.c:6143 [inline]
kfree+0x1f6/0x6b0 mm/slub.c:6461
l2cap_chan_destroy net/bluetooth/l2cap_core.c:491 [inline]
kref_put include/linux/kref.h:65 [inline]
l2cap_chan_put+0x235/0x300 net/bluetooth/l2cap_core.c:516
l2cap_sock_cleanup_listen+0x4d/0x2d0 net/bluetooth/l2cap_sock.c:1493
l2cap_sock_release+0x69/0x280 net/bluetooth/l2cap_sock.c:1451
__sock_release+0xb3/0x260 net/socket.c:662
sock_close+0x1c/0x30 net/socket.c:1455
__fput+0x3ff/0xb40 fs/file_table.c:469
task_work_run+0x150/0x240 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
exit_to_user_mode_loop+0x100/0x4a0 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
do_syscall_64+0x67c/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff8880568eb000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1152 bytes inside of
freed 2048-byte region [ffff8880568eb000, ffff8880568eb800)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x568e8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88813fe3a000 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800080008 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88813fe3a000 dead000000000100 dead000000000122
head: 0000000000000000 0000000800080008 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea00015a3a01 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 5834, tgid 5834 (kworker/1:4), ts 91339737017, free_ts 23444776449
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889
prep_new_page mm/page_alloc.c:1897 [inline]
get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3962
__alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5250
alloc_slab_page mm/slub.c:3269 [inline]
allocate_slab mm/slub.c:3458 [inline]
new_slab+0xa6/0x6d0 mm/slub.c:3516
refill_objects+0x26b/0x400 mm/slub.c:7153
refill_sheaf mm/slub.c:2818 [inline]
alloc_full_sheaf mm/slub.c:2839 [inline]
__pcs_replace_empty_main+0x19f/0x600 mm/slub.c:4602
alloc_from_pcs mm/slub.c:4695 [inline]
slab_alloc_node mm/slub.c:4829 [inline]
__do_kmalloc_node mm/slub.c:5237 [inline]
__kmalloc_node_track_caller_noprof+0x694/0x850 mm/slub.c:5346
kmalloc_reserve+0xe8/0x350 net/core/skbuff.c:635
__alloc_skb+0x185/0x710 net/core/skbuff.c:713
alloc_skb include/linux/skbuff.h:1383 [inline]
mld_newpack.isra.0+0x18e/0xa20 net/ipv6/mcast.c:1775
add_grhead+0x299/0x340 net/ipv6/mcast.c:1886
add_grec+0x1380/0x1920 net/ipv6/mcast.c:2025
mld_send_cr net/ipv6/mcast.c:2148 [inline]
mld_ifc_work+0x3c5/0xc10 net/ipv6/mcast.c:2693
process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275
process_scheduled_works kernel/workqueue.c:3358 [inline]
worker_thread+0x5da/0xe40 kernel/workqueue.c:3439
kthread+0x370/0x450 kernel/kthread.c:467
page last free pid 1 tgid 1 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1433 [inline]
__free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978
__free_pages mm/page_alloc.c:5369 [inline]
free_contig_range+0xde/0x1d0 mm/page_alloc.c:7374
debug_vm_pgtable_free_huge_page mm/debug_vm_pgtable.c:980 [inline]
destroy_args+0xa8/0x7a0 mm/debug_vm_pgtable.c:993
debug_vm_pgtable+0x1b66/0x34c0 mm/debug_vm_pgtable.c:1368
do_one_initcall+0x11d/0x760 init/main.c:1382
do_initcall_level init/main.c:1444 [inline]
do_initcalls init/main.c:1460 [inline]
do_basic_setup init/main.c:1479 [inline]
kernel_init_freeable+0x6e5/0x7a0 init/main.c:1692
kernel_init+0x1f/0x1e0 init/main.c:1582
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Memory state around the buggy address:
ffff8880568eb380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880568eb400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880568eb480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8880568eb500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880568eb580: 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:82 [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:828 [inline]
BUG: KASAN: wild-memory-access in l2cap_conn_ready net/bluetooth/l2cap_core.c:1618 [inline]
BUG: KASAN: wild-memory-access in l2cap_connect_cfm+0x7c0/0x1050 net/bluetooth/l2cap_core.c:7368
Read of size 4 at addr deacfffffffffc8c by task kworker/u9:1/26188
CPU: 1 UID: 0 PID: 26188 Comm: kworker/u9:1 Tainted: G B L syzkaller #0 PREEMPT(full)
Tainted: [B]=BAD_PAGE, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: hci4 hci_rx_work
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
kasan_report+0xdf/0x1e0 mm/kasan/report.c:595
check_region_inline mm/kasan/generic.c:186 [inline]
kasan_check_range+0x10f/0x1e0 mm/kasan/generic.c:200
instrument_atomic_read include/linux/instrumented.h:82 [inline]
atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
l2cap_chan_lock include/net/bluetooth/l2cap.h:828 [inline]
l2cap_conn_ready net/bluetooth/l2cap_core.c:1618 [inline]
l2cap_connect_cfm+0x7c0/0x1050 net/bluetooth/l2cap_core.c:7368
hci_connect_cfm include/net/bluetooth/hci_core.h:2139 [inline]
le_conn_complete_evt+0x195c/0x1f40 net/bluetooth/hci_event.c:5847
hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5873
hci_le_meta_evt+0x34a/0x5f0 net/bluetooth/hci_event.c:7473
hci_event_func net/bluetooth/hci_event.c:7781 [inline]
hci_event_packet+0x682/0x11c0 net/bluetooth/hci_event.c:7838
hci_rx_work+0x451/0xfc0 net/bluetooth/hci_core.c:4077
process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275
process_scheduled_works kernel/workqueue.c:3358 [inline]
worker_thread+0x5da/0xe40 kernel/workqueue.c:3439
kthread+0x370/0x450 kernel/kthread.c:467
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
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: 26188 Comm: kworker/u9:1 Tainted: G B L syzkaller #0 PREEMPT(full)
Tainted: [B]=BAD_PAGE, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: hci4 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:828 [inline]
RIP: 0010:l2cap_conn_ready net/bluetooth/l2cap_core.c:1618 [inline]
RIP: 0010:l2cap_connect_cfm+0x7c7/0x1050 net/bluetooth/l2cap_core.c:7368
Code: 80 fb ff ff 49 39 c7 0f 84 29 01 00 00 e8 b1 06 78 f7 49 8d 6e 0c be 04 00 00 00 48 89 ef e8 b0 93 e3 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 89
RSP: 0018:ffffc90006b5f838 EFLAGS: 00010213
RAX: 1bd59fffffffff91 RBX: dffffc0000000000 RCX: ffffc9001e634000
RDX: 0000000000000000 RSI: ffffffff81c6f05d RDI: ffff888029021e80
RBP: deacfffffffffc8c R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 3d3d3d3d3d3d3d3d R12: ffff88805798803d
R13: 0000000000000080 R14: deacfffffffffc80 R15: ffff888063006280
FS: 0000000000000000(0000) GS:ffff888124445000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055556bddca68 CR3: 0000000090bf5000 CR4: 0000000000350ef0
Call Trace:
hci_connect_cfm include/net/bluetooth/hci_core.h:2139 [inline]
le_conn_complete_evt+0x195c/0x1f40 net/bluetooth/hci_event.c:5847
hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5873
hci_le_meta_evt+0x34a/0x5f0 net/bluetooth/hci_event.c:7473
hci_event_func net/bluetooth/hci_event.c:7781 [inline]
hci_event_packet+0x682/0x11c0 net/bluetooth/hci_event.c:7838
hci_rx_work+0x451/0xfc0 net/bluetooth/hci_core.c:4077
process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275
process_scheduled_works kernel/workqueue.c:3358 [inline]
worker_thread+0x5da/0xe40 kernel/workqueue.c:3439
kthread+0x370/0x450 kernel/kthread.c:467
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
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:828 [inline]
RIP: 0010:l2cap_conn_ready net/bluetooth/l2cap_core.c:1618 [inline]
RIP: 0010:l2cap_connect_cfm+0x7c7/0x1050 net/bluetooth/l2cap_core.c:7368
Code: 80 fb ff ff 49 39 c7 0f 84 29 01 00 00 e8 b1 06 78 f7 49 8d 6e 0c be 04 00 00 00 48 89 ef e8 b0 93 e3 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 89
RSP: 0018:ffffc90006b5f838 EFLAGS: 00010213
RAX: 1bd59fffffffff91 RBX: dffffc0000000000 RCX: ffffc9001e634000
RDX: 0000000000000000 RSI: ffffffff81c6f05d RDI: ffff888029021e80
RBP: deacfffffffffc8c R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 3d3d3d3d3d3d3d3d R12: ffff88805798803d
R13: 0000000000000080 R14: deacfffffffffc80 R15: ffff888063006280
FS: 0000000000000000(0000) GS:ffff888124445000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055556bddca68 CR3: 000000007be5b000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess), 4 bytes skipped:
0: 49 39 c7 cmp %rax,%r15
3: 0f 84 29 01 00 00 je 0x132
9: e8 b1 06 78 f7 call 0xf77806bf
e: 49 8d 6e 0c lea 0xc(%r14),%rbp
12: be 04 00 00 00 mov $0x4,%esi
17: 48 89 ef mov %rbp,%rdi
1a: e8 b0 93 e3 f7 call 0xf7e393cf
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 .byte 0x85
3b: 89 .byte 0x89