==================================================================
BUG: KASAN: slab-use-after-free in l2cap_conn_ready net/bluetooth/l2cap_core.c:1624 [inline]
BUG: KASAN: slab-use-after-free in l2cap_connect_cfm+0xe47/0x1010 net/bluetooth/l2cap_core.c:7305
Read of size 8 at addr ffff8880568cb480 by task kworker/u9:6/5847
CPU: 1 UID: 0 PID: 5847 Comm: kworker/u9:6 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: hci2 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:1624 [inline]
l2cap_connect_cfm+0xe47/0x1010 net/bluetooth/l2cap_core.c:7305
hci_connect_cfm include/net/bluetooth/hci_core.h:2131 [inline]
le_conn_complete_evt+0x1991/0x1fa0 net/bluetooth/hci_event.c:5821
hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5847
hci_le_meta_evt+0x357/0x610 net/bluetooth/hci_event.c:7408
hci_event_func net/bluetooth/hci_event.c:7716 [inline]
hci_event_packet+0x685/0x1210 net/bluetooth/hci_event.c:7773
hci_rx_work+0x2c9/0x1020 net/bluetooth/hci_core.c:4076
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Allocated by task 5847:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
poison_kmalloc_redzone mm/kasan/common.c:397 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:414
kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
l2cap_chan_create+0x44/0x930 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+0x4f0/0x1010 net/bluetooth/l2cap_core.c:7288
hci_connect_cfm include/net/bluetooth/hci_core.h:2131 [inline]
le_conn_complete_evt+0x1991/0x1fa0 net/bluetooth/hci_event.c:5821
hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5847
hci_le_meta_evt+0x357/0x610 net/bluetooth/hci_event.c:7408
hci_event_func net/bluetooth/hci_event.c:7716 [inline]
hci_event_packet+0x685/0x1210 net/bluetooth/hci_event.c:7773
hci_rx_work+0x2c9/0x1020 net/bluetooth/hci_core.c:4076
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Freed by task 3281:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:252 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284
kasan_slab_free include/linux/kasan.h:234 [inline]
slab_free_hook mm/slub.c:2540 [inline]
slab_free mm/slub.c:6670 [inline]
kfree+0x2f8/0x6e0 mm/slub.c:6878
l2cap_chan_destroy net/bluetooth/l2cap_core.c:491 [inline]
kref_put include/linux/kref.h:65 [inline]
l2cap_chan_put+0x1bb/0x310 net/bluetooth/l2cap_core.c:516
l2cap_sock_cleanup_listen+0x4d/0x2f0 net/bluetooth/l2cap_sock.c:1468
l2cap_sock_release+0x69/0x280 net/bluetooth/l2cap_sock.c:1426
__sock_release+0xb3/0x270 net/socket.c:662
sock_close+0x1c/0x30 net/socket.c:1455
__fput+0x402/0xb70 fs/file_table.c:468
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:44 [inline]
exit_to_user_mode_loop+0xfb/0x540 kernel/entry/common.c:75
__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_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff8880568cb000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1152 bytes inside of
freed 2048-byte region [ffff8880568cb000, ffff8880568cb800)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x568c8
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 ffff88813ff27000 ffffea0000ccea00 0000000000000002
raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88813ff27000 ffffea0000ccea00 0000000000000002
head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea00015a3201 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 2882, tgid 2879 (syz.6.5209), ts 1096696813941, free_ts 1056168325079
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1846
prep_new_page mm/page_alloc.c:1854 [inline]
get_page_from_freelist+0xd0b/0x31a0 mm/page_alloc.c:3915
__alloc_frozen_pages_noprof+0x25f/0x2430 mm/page_alloc.c:5210
alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486
alloc_slab_page mm/slub.c:3075 [inline]
allocate_slab mm/slub.c:3248 [inline]
new_slab+0x2c3/0x430 mm/slub.c:3302
___slab_alloc+0xe18/0x1c90 mm/slub.c:4656
__slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4779
__slab_alloc_node mm/slub.c:4855 [inline]
slab_alloc_node mm/slub.c:5251 [inline]
__do_kmalloc_node mm/slub.c:5656 [inline]
__kmalloc_node_noprof+0x4d8/0x930 mm/slub.c:5663
kmalloc_node_noprof include/linux/slab.h:987 [inline]
qdisc_alloc+0xb7/0xa50 net/sched/sch_generic.c:951
qdisc_create_dflt+0x94/0x460 net/sched/sch_generic.c:1008
mq_init+0x345/0x490 net/sched/sch_mq.c:90
qdisc_create_dflt+0x125/0x460 net/sched/sch_generic.c:1015
attach_default_qdiscs net/sched/sch_generic.c:1197 [inline]
dev_activate+0xaae/0x12d0 net/sched/sch_generic.c:1251
__dev_open+0x4f1/0x960 net/core/dev.c:1692
__dev_change_flags+0x55d/0x6f0 net/core/dev.c:9734
netif_change_flags+0x8d/0x160 net/core/dev.c:9797
page last free pid 23 tgid 23 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1395 [inline]
__free_frozen_pages+0x7df/0x1170 mm/page_alloc.c:2943
rcu_do_batch kernel/rcu/tree.c:2605 [inline]
rcu_core+0x79c/0x15f0 kernel/rcu/tree.c:2857
handle_softirqs+0x219/0x950 kernel/softirq.c:622
run_ksoftirqd kernel/softirq.c:1063 [inline]
run_ksoftirqd+0x3a/0x60 kernel/softirq.c:1055
smpboot_thread_fn+0x3f7/0xae0 kernel/smpboot.c:160
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Memory state around the buggy address:
ffff8880568cb380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880568cb400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880568cb480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8880568cb500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880568cb580: 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:1626 [inline]
BUG: KASAN: wild-memory-access in l2cap_connect_cfm+0x80f/0x1010 net/bluetooth/l2cap_core.c:7305
Read of size 4 at addr deacfffffffffc8c by task kworker/u9:6/5847
CPU: 1 UID: 0 PID: 5847 Comm: kworker/u9:6 Tainted: G B syzkaller #0 PREEMPT(full)
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: hci2 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:194 [inline]
kasan_check_range+0x100/0x1b0 mm/kasan/generic.c:200
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:1626 [inline]
l2cap_connect_cfm+0x80f/0x1010 net/bluetooth/l2cap_core.c:7305
hci_connect_cfm include/net/bluetooth/hci_core.h:2131 [inline]
le_conn_complete_evt+0x1991/0x1fa0 net/bluetooth/hci_event.c:5821
hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5847
hci_le_meta_evt+0x357/0x610 net/bluetooth/hci_event.c:7408
hci_event_func net/bluetooth/hci_event.c:7716 [inline]
hci_event_packet+0x685/0x1210 net/bluetooth/hci_event.c:7773
hci_rx_work+0x2c9/0x1020 net/bluetooth/hci_core.c:4076
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
==================================================================
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: 5847 Comm: kworker/u9:6 Tainted: G B syzkaller #0 PREEMPT(full)
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: hci2 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:1626 [inline]
RIP: 0010:l2cap_connect_cfm+0x816/0x1010 net/bluetooth/l2cap_core.c:7305
Code: 80 fb ff ff 49 39 c5 0f 84 29 01 00 00 e8 72 61 46 f7 49 8d 6f 0c be 04 00 00 00 48 89 ef e8 41 4e af 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 27
RSP: 0018:ffffc900040df7d8 EFLAGS: 00010213
RAX: 1bd59fffffffff91 RBX: dffffc0000000000 RCX: ffffc9001e2ef000
RDX: 0000000000100000 RSI: ffffffff82279267 RDI: 0000000000000007
RBP: deacfffffffffc8c R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 3d3d3d3d3d3d3d3d R12: ffff88807b57003d
R13: ffff888042d142c0 R14: 0000000000000080 R15: deacfffffffffc80
FS: 0000000000000000(0000) GS:ffff8881249f6000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8b88fe1ac0 CR3: 0000000032900000 CR4: 0000000000350ef0
Call Trace:
hci_connect_cfm include/net/bluetooth/hci_core.h:2131 [inline]
le_conn_complete_evt+0x1991/0x1fa0 net/bluetooth/hci_event.c:5821
hci_le_conn_complete_evt+0x23c/0x3a0 net/bluetooth/hci_event.c:5847
hci_le_meta_evt+0x357/0x610 net/bluetooth/hci_event.c:7408
hci_event_func net/bluetooth/hci_event.c:7716 [inline]
hci_event_packet+0x685/0x1210 net/bluetooth/hci_event.c:7773
hci_rx_work+0x2c9/0x1020 net/bluetooth/hci_core.c:4076
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
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:1626 [inline]
RIP: 0010:l2cap_connect_cfm+0x816/0x1010 net/bluetooth/l2cap_core.c:7305
Code: 80 fb ff ff 49 39 c5 0f 84 29 01 00 00 e8 72 61 46 f7 49 8d 6f 0c be 04 00 00 00 48 89 ef e8 41 4e af 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 27
RSP: 0018:ffffc900040df7d8 EFLAGS: 00010213
RAX: 1bd59fffffffff91 RBX: dffffc0000000000 RCX: ffffc9001e2ef000
RDX: 0000000000100000 RSI: ffffffff82279267 RDI: 0000000000000007
RBP: deacfffffffffc8c R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 3d3d3d3d3d3d3d3d R12: ffff88807b57003d
R13: ffff888042d142c0 R14: 0000000000000080 R15: deacfffffffffc80
FS: 0000000000000000(0000) GS:ffff8881248f6000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8b86fd5d58 CR3: 000000007f0ac000 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 72 61 46 f7 call 0xf7466180
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 41 4e af f7 call 0xf7af4e60
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 27 test %esp,(%rdi)