Extracting prog: 2m38.888958832s
Minimizing prog: 1h2m23.052653401s
Simplifying prog options: 12m15.708715816s
Extracting C: 5m9.093760065s
Simplifying C: 0s


extracting reproducer from 1 programs
testing a last program of every proc
single: executing 1 programs separately with timeout 30s
testing program (duration=30s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_init_net_socket$bt_l2cap-bind$bt_l2cap-socket$alg-accept4-pselect6-listen-syz_emit_vhci
detailed listing:
executing program 0:
r0 = syz_init_net_socket$bt_l2cap(0x1f, 0x5, 0x0)
bind$bt_l2cap(r0, &(0x7f0000000000)={0x1f, 0x0, @any, 0x4, 0x1}, 0xe)
r1 = socket$alg(0x26, 0x5, 0x0)
accept4(r1, 0x0, 0x0, 0x0)
pselect6(0x40, &(0x7f0000000000)={0x10}, 0x0, 0x0, 0x0, 0x0)
listen(r0, 0x3)
syz_emit_vhci(&(0x7f0000000100)=ANY=[@ANYBLOB="043e130100c90001"], 0x16)

program did not crash
single: failed to extract reproducer
single: executing 1 programs separately with timeout 6m0s
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_init_net_socket$bt_l2cap-bind$bt_l2cap-socket$alg-accept4-pselect6-listen-syz_emit_vhci
detailed listing:
executing program 0:
r0 = syz_init_net_socket$bt_l2cap(0x1f, 0x5, 0x0)
bind$bt_l2cap(r0, &(0x7f0000000000)={0x1f, 0x0, @any, 0x4, 0x1}, 0xe)
r1 = socket$alg(0x26, 0x5, 0x0)
accept4(r1, 0x0, 0x0, 0x0)
pselect6(0x40, &(0x7f0000000000)={0x10}, 0x0, 0x0, 0x0, 0x0)
listen(r0, 0x3)
syz_emit_vhci(&(0x7f0000000100)=ANY=[@ANYBLOB="043e130100c90001"], 0x16)

program crashed: KASAN: slab-use-after-free Read in l2cap_connect_cfm
single: successfully extracted reproducer
found reproducer with 7 syscalls
minimizing guilty program
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_init_net_socket$bt_l2cap-bind$bt_l2cap-socket$alg-accept4-pselect6-listen
detailed listing:
executing program 0:
r0 = syz_init_net_socket$bt_l2cap(0x1f, 0x5, 0x0)
bind$bt_l2cap(r0, &(0x7f0000000000)={0x1f, 0x0, @any, 0x4, 0x1}, 0xe)
r1 = socket$alg(0x26, 0x5, 0x0)
accept4(r1, 0x0, 0x0, 0x0)
pselect6(0x40, &(0x7f0000000000)={0x10}, 0x0, 0x0, 0x0, 0x0)
listen(r0, 0x3)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_init_net_socket$bt_l2cap-bind$bt_l2cap-socket$alg-accept4-pselect6-syz_emit_vhci
detailed listing:
executing program 0:
r0 = syz_init_net_socket$bt_l2cap(0x1f, 0x5, 0x0)
bind$bt_l2cap(r0, &(0x7f0000000000)={0x1f, 0x0, @any, 0x4, 0x1}, 0xe)
r1 = socket$alg(0x26, 0x5, 0x0)
accept4(r1, 0x0, 0x0, 0x0)
pselect6(0x40, &(0x7f0000000000)={0x10}, 0x0, 0x0, 0x0, 0x0)
syz_emit_vhci(&(0x7f0000000100)=ANY=[@ANYBLOB="043e130100c90001"], 0x16)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_init_net_socket$bt_l2cap-bind$bt_l2cap-socket$alg-accept4-listen-syz_emit_vhci
detailed listing:
executing program 0:
r0 = syz_init_net_socket$bt_l2cap(0x1f, 0x5, 0x0)
bind$bt_l2cap(r0, &(0x7f0000000000)={0x1f, 0x0, @any, 0x4, 0x1}, 0xe)
r1 = socket$alg(0x26, 0x5, 0x0)
accept4(r1, 0x0, 0x0, 0x0)
listen(r0, 0x3)
syz_emit_vhci(&(0x7f0000000100)=ANY=[@ANYBLOB="043e130100c90001"], 0x16)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_init_net_socket$bt_l2cap-bind$bt_l2cap-socket$alg-pselect6-listen-syz_emit_vhci
detailed listing:
executing program 0:
r0 = syz_init_net_socket$bt_l2cap(0x1f, 0x5, 0x0)
bind$bt_l2cap(r0, &(0x7f0000000000)={0x1f, 0x0, @any, 0x4, 0x1}, 0xe)
socket$alg(0x26, 0x5, 0x0)
pselect6(0x40, &(0x7f0000000000)={0x10}, 0x0, 0x0, 0x0, 0x0)
listen(r0, 0x3)
syz_emit_vhci(&(0x7f0000000100)=ANY=[@ANYBLOB="043e130100c90001"], 0x16)

program crashed: KASAN: slab-use-after-free Read in l2cap_connect_cfm
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_init_net_socket$bt_l2cap-bind$bt_l2cap-pselect6-listen-syz_emit_vhci
detailed listing:
executing program 0:
r0 = syz_init_net_socket$bt_l2cap(0x1f, 0x5, 0x0)
bind$bt_l2cap(r0, &(0x7f0000000000)={0x1f, 0x0, @any, 0x4, 0x1}, 0xe)
pselect6(0x40, &(0x7f0000000000)={0x10}, 0x0, 0x0, 0x0, 0x0)
listen(r0, 0x3)
syz_emit_vhci(&(0x7f0000000100)=ANY=[@ANYBLOB="043e130100c90001"], 0x16)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_init_net_socket$bt_l2cap-socket$alg-pselect6-listen-syz_emit_vhci
detailed listing:
executing program 0:
r0 = syz_init_net_socket$bt_l2cap(0x1f, 0x5, 0x0)
socket$alg(0x26, 0x5, 0x0)
pselect6(0x40, &(0x7f0000000000)={0x10}, 0x0, 0x0, 0x0, 0x0)
listen(r0, 0x3)
syz_emit_vhci(&(0x7f0000000100)=ANY=[@ANYBLOB="043e130100c90001"], 0x16)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): bind$bt_l2cap-socket$alg-pselect6-listen-syz_emit_vhci
detailed listing:
executing program 0:
bind$bt_l2cap(0xffffffffffffffff, &(0x7f0000000000)={0x1f, 0x0, @any, 0x4, 0x1}, 0xe)
socket$alg(0x26, 0x5, 0x0)
pselect6(0x40, &(0x7f0000000000)={0x10}, 0x0, 0x0, 0x0, 0x0)
listen(0xffffffffffffffff, 0x3)
syz_emit_vhci(&(0x7f0000000100)=ANY=[@ANYBLOB="043e130100c90001"], 0x16)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_init_net_socket$bt_l2cap-bind$bt_l2cap-socket$alg-pselect6-listen-syz_emit_vhci
detailed listing:
executing program 0:
r0 = syz_init_net_socket$bt_l2cap(0x1f, 0x5, 0x0)
bind$bt_l2cap(r0, 0x0, 0x0)
socket$alg(0x26, 0x5, 0x0)
pselect6(0x40, &(0x7f0000000000)={0x10}, 0x0, 0x0, 0x0, 0x0)
listen(r0, 0x3)
syz_emit_vhci(&(0x7f0000000100)=ANY=[@ANYBLOB="043e130100c90001"], 0x16)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_init_net_socket$bt_l2cap-bind$bt_l2cap-socket$alg-pselect6-listen-syz_emit_vhci
detailed listing:
executing program 0:
r0 = syz_init_net_socket$bt_l2cap(0x1f, 0x5, 0x0)
bind$bt_l2cap(r0, &(0x7f0000000000)={0x1f, 0x0, @any, 0x4, 0x1}, 0xe)
socket$alg(0x26, 0x5, 0x0)
pselect6(0x0, 0x0, 0x0, 0x0, 0x0, 0x0)
listen(r0, 0x3)
syz_emit_vhci(&(0x7f0000000100)=ANY=[@ANYBLOB="043e130100c90001"], 0x16)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_init_net_socket$bt_l2cap-bind$bt_l2cap-socket$alg-pselect6-listen-syz_emit_vhci
detailed listing:
executing program 0:
r0 = syz_init_net_socket$bt_l2cap(0x1f, 0x5, 0x0)
bind$bt_l2cap(r0, &(0x7f0000000000)={0x1f, 0x0, @any, 0x4, 0x1}, 0xe)
socket$alg(0x26, 0x5, 0x0)
pselect6(0x40, &(0x7f0000000000)={0x10}, 0x0, 0x0, 0x0, 0x0)
listen(r0, 0x3)
syz_emit_vhci(0x0, 0x16)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_init_net_socket$bt_l2cap-bind$bt_l2cap-socket$alg-pselect6-listen-syz_emit_vhci
detailed listing:
executing program 0:
r0 = syz_init_net_socket$bt_l2cap(0x1f, 0x5, 0x0)
bind$bt_l2cap(r0, &(0x7f0000000000)={0x1f, 0x0, @any, 0x4, 0x1}, 0xe)
socket$alg(0x26, 0x5, 0x0)
pselect6(0x40, &(0x7f0000000000)={0x10}, 0x0, 0x0, 0x0, 0x0)
listen(r0, 0x3)
syz_emit_vhci(&(0x7f0000000100)=ANY=[@ANYBLOB], 0x16)

program did not crash
extracting C reproducer
testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_init_net_socket$bt_l2cap-bind$bt_l2cap-socket$alg-pselect6-listen-syz_emit_vhci
program crashed: no output from test machine
a never seen crash title: no output from test machine, ignore
simplifying guilty program options
testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_init_net_socket$bt_l2cap-bind$bt_l2cap-socket$alg-pselect6-listen-syz_emit_vhci
detailed listing:
executing program 0:
r0 = syz_init_net_socket$bt_l2cap(0x1f, 0x5, 0x0)
bind$bt_l2cap(r0, &(0x7f0000000000)={0x1f, 0x0, @any, 0x4, 0x1}, 0xe)
socket$alg(0x26, 0x5, 0x0)
pselect6(0x40, &(0x7f0000000000)={0x10}, 0x0, 0x0, 0x0, 0x0)
listen(r0, 0x3)
syz_emit_vhci(&(0x7f0000000100)=ANY=[@ANYBLOB="043e130100c90001"], 0x16)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_init_net_socket$bt_l2cap-bind$bt_l2cap-socket$alg-pselect6-listen-syz_emit_vhci
detailed listing:
executing program 0:
r0 = syz_init_net_socket$bt_l2cap(0x1f, 0x5, 0x0)
bind$bt_l2cap(r0, &(0x7f0000000000)={0x1f, 0x0, @any, 0x4, 0x1}, 0xe)
socket$alg(0x26, 0x5, 0x0)
pselect6(0x40, &(0x7f0000000000)={0x10}, 0x0, 0x0, 0x0, 0x0)
listen(r0, 0x3)
syz_emit_vhci(&(0x7f0000000100)=ANY=[@ANYBLOB="043e130100c90001"], 0x16)

program did not crash
reproducing took 1h22m26.744115215s
repro crashed as (corrupted=false):
kobject: kobject_add_internal failed for hci0:201 with -EEXIST, don't try to register things with the same name in the same directory.
Bluetooth: hci0: failed to register connection device
==================================================================
BUG: KASAN: slab-use-after-free in l2cap_connect_cfm+0x68b/0x1090 net/bluetooth/l2cap_core.c:7245
Read of size 8 at addr ffff888012a9d480 by task kworker/u5:2/5393

CPU: 0 UID: 0 PID: 5393 Comm: kworker/u5:2 Not tainted 6.14.0-rc5-syzkaller-00039-g848e07631744 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: hci0 hci_rx_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0x16e/0x5b0 mm/kasan/report.c:521
 kasan_report+0x143/0x180 mm/kasan/report.c:634
 l2cap_connect_cfm+0x68b/0x1090 net/bluetooth/l2cap_core.c:7245
 hci_connect_cfm+0x162/0x240 include/net/bluetooth/hci_core.h:2051
 le_conn_complete_evt+0xda8/0x1360 net/bluetooth/hci_event.c:5763
 hci_le_conn_complete_evt+0x18c/0x420 net/bluetooth/hci_event.c:5789
 hci_event_func net/bluetooth/hci_event.c:7470 [inline]
 hci_event_packet+0xa54/0x1540 net/bluetooth/hci_event.c:7525
 hci_rx_work+0x3f3/0xdb0 net/bluetooth/hci_core.c:4015
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd30 kernel/workqueue.c:3400
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 5393:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __kmalloc_cache_noprof+0x243/0x390 mm/slub.c:4325
 kmalloc_noprof include/linux/slab.h:901 [inline]
 kzalloc_noprof include/linux/slab.h:1037 [inline]
 l2cap_chan_create+0x50/0x760 net/bluetooth/l2cap_core.c:445
 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1887 [inline]
 l2cap_sock_new_connection_cb+0x181/0x2b0 net/bluetooth/l2cap_sock.c:1469
 l2cap_connect_cfm+0x336/0x1090 net/bluetooth/l2cap_core.c:7228
 hci_connect_cfm+0x162/0x240 include/net/bluetooth/hci_core.h:2051
 le_conn_complete_evt+0xda8/0x1360 net/bluetooth/hci_event.c:5763
 hci_le_conn_complete_evt+0x18c/0x420 net/bluetooth/hci_event.c:5789
 hci_event_func net/bluetooth/hci_event.c:7470 [inline]
 hci_event_packet+0xa54/0x1540 net/bluetooth/hci_event.c:7525
 hci_rx_work+0x3f3/0xdb0 net/bluetooth/hci_core.c:4015
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd30 kernel/workqueue.c:3400
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Freed by task 5677:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2353 [inline]
 slab_free mm/slub.c:4609 [inline]
 kfree+0x196/0x430 mm/slub.c:4757
 l2cap_sock_cleanup_listen+0xed/0x3c0 net/bluetooth/l2cap_sock.c:1452
 l2cap_sock_release+0x5d/0x1d0 net/bluetooth/l2cap_sock.c:1412
 __sock_release net/socket.c:647 [inline]
 sock_close+0xbc/0x240 net/socket.c:1398
 __fput+0x3e9/0x9f0 fs/file_table.c:464
 task_work_run+0x24f/0x310 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x13f/0x340 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888012a9d000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1152 bytes inside of
 freed 2048-byte region [ffff888012a9d000, ffff888012a9d800)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12a98
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 ffff88801b042000 ffffea000071d600 dead000000000002
raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b042000 ffffea000071d600 dead000000000002
head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea00004aa601 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 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 5484, tgid 5484 (syz-executor), ts 391681570419, free_ts 391676519320
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551
 prep_new_page mm/page_alloc.c:1559 [inline]
 get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3477
 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4739
 alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2270
 alloc_slab_page mm/slub.c:2423 [inline]
 allocate_slab+0x8f/0x3a0 mm/slub.c:2587
 new_slab mm/slub.c:2640 [inline]
 ___slab_alloc+0xc27/0x14a0 mm/slub.c:3826
 __slab_alloc+0x58/0xa0 mm/slub.c:3916
 __slab_alloc_node mm/slub.c:3991 [inline]
 slab_alloc_node mm/slub.c:4152 [inline]
 __kmalloc_cache_noprof+0x27b/0x390 mm/slub.c:4320
 kmalloc_noprof include/linux/slab.h:901 [inline]
 rtnl_newlink+0x147/0x1d30 net/core/rtnetlink.c:3922
 rtnetlink_rcv_msg+0x791/0xcf0 net/core/rtnetlink.c:6912
 netlink_rcv_skb+0x206/0x480 net/netlink/af_netlink.c:2533
 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
 netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1338
 netlink_sendmsg+0x8de/0xcb0 net/netlink/af_netlink.c:1882
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:733
 __sys_sendto+0x363/0x4c0 net/socket.c:2187
 __do_sys_sendto net/socket.c:2194 [inline]
 __se_sys_sendto net/socket.c:2190 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2190
page last free pid 5550 tgid 5550 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2660
 __slab_free+0x2c2/0x380 mm/slub.c:4520
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4115 [inline]
 slab_alloc_node mm/slub.c:4164 [inline]
 kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4171
 getname_flags+0xb7/0x540 fs/namei.c:139
 do_sys_openat2+0xd2/0x1d0 fs/open.c:1422
 do_sys_open fs/open.c:1443 [inline]
 __do_sys_openat fs/open.c:1459 [inline]
 __se_sys_openat fs/open.c:1454 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1454
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888012a9d380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888012a9d400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888012a9d480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff888012a9d500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888012a9d580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

final repro crashed as (corrupted=false):
kobject: kobject_add_internal failed for hci0:201 with -EEXIST, don't try to register things with the same name in the same directory.
Bluetooth: hci0: failed to register connection device
==================================================================
BUG: KASAN: slab-use-after-free in l2cap_connect_cfm+0x68b/0x1090 net/bluetooth/l2cap_core.c:7245
Read of size 8 at addr ffff888012a9d480 by task kworker/u5:2/5393

CPU: 0 UID: 0 PID: 5393 Comm: kworker/u5:2 Not tainted 6.14.0-rc5-syzkaller-00039-g848e07631744 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: hci0 hci_rx_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0x16e/0x5b0 mm/kasan/report.c:521
 kasan_report+0x143/0x180 mm/kasan/report.c:634
 l2cap_connect_cfm+0x68b/0x1090 net/bluetooth/l2cap_core.c:7245
 hci_connect_cfm+0x162/0x240 include/net/bluetooth/hci_core.h:2051
 le_conn_complete_evt+0xda8/0x1360 net/bluetooth/hci_event.c:5763
 hci_le_conn_complete_evt+0x18c/0x420 net/bluetooth/hci_event.c:5789
 hci_event_func net/bluetooth/hci_event.c:7470 [inline]
 hci_event_packet+0xa54/0x1540 net/bluetooth/hci_event.c:7525
 hci_rx_work+0x3f3/0xdb0 net/bluetooth/hci_core.c:4015
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd30 kernel/workqueue.c:3400
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 5393:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __kmalloc_cache_noprof+0x243/0x390 mm/slub.c:4325
 kmalloc_noprof include/linux/slab.h:901 [inline]
 kzalloc_noprof include/linux/slab.h:1037 [inline]
 l2cap_chan_create+0x50/0x760 net/bluetooth/l2cap_core.c:445
 l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1887 [inline]
 l2cap_sock_new_connection_cb+0x181/0x2b0 net/bluetooth/l2cap_sock.c:1469
 l2cap_connect_cfm+0x336/0x1090 net/bluetooth/l2cap_core.c:7228
 hci_connect_cfm+0x162/0x240 include/net/bluetooth/hci_core.h:2051
 le_conn_complete_evt+0xda8/0x1360 net/bluetooth/hci_event.c:5763
 hci_le_conn_complete_evt+0x18c/0x420 net/bluetooth/hci_event.c:5789
 hci_event_func net/bluetooth/hci_event.c:7470 [inline]
 hci_event_packet+0xa54/0x1540 net/bluetooth/hci_event.c:7525
 hci_rx_work+0x3f3/0xdb0 net/bluetooth/hci_core.c:4015
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd30 kernel/workqueue.c:3400
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Freed by task 5677:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2353 [inline]
 slab_free mm/slub.c:4609 [inline]
 kfree+0x196/0x430 mm/slub.c:4757
 l2cap_sock_cleanup_listen+0xed/0x3c0 net/bluetooth/l2cap_sock.c:1452
 l2cap_sock_release+0x5d/0x1d0 net/bluetooth/l2cap_sock.c:1412
 __sock_release net/socket.c:647 [inline]
 sock_close+0xbc/0x240 net/socket.c:1398
 __fput+0x3e9/0x9f0 fs/file_table.c:464
 task_work_run+0x24f/0x310 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x13f/0x340 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888012a9d000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1152 bytes inside of
 freed 2048-byte region [ffff888012a9d000, ffff888012a9d800)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12a98
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 ffff88801b042000 ffffea000071d600 dead000000000002
raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b042000 ffffea000071d600 dead000000000002
head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea00004aa601 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 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 5484, tgid 5484 (syz-executor), ts 391681570419, free_ts 391676519320
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551
 prep_new_page mm/page_alloc.c:1559 [inline]
 get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3477
 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4739
 alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2270
 alloc_slab_page mm/slub.c:2423 [inline]
 allocate_slab+0x8f/0x3a0 mm/slub.c:2587
 new_slab mm/slub.c:2640 [inline]
 ___slab_alloc+0xc27/0x14a0 mm/slub.c:3826
 __slab_alloc+0x58/0xa0 mm/slub.c:3916
 __slab_alloc_node mm/slub.c:3991 [inline]
 slab_alloc_node mm/slub.c:4152 [inline]
 __kmalloc_cache_noprof+0x27b/0x390 mm/slub.c:4320
 kmalloc_noprof include/linux/slab.h:901 [inline]
 rtnl_newlink+0x147/0x1d30 net/core/rtnetlink.c:3922
 rtnetlink_rcv_msg+0x791/0xcf0 net/core/rtnetlink.c:6912
 netlink_rcv_skb+0x206/0x480 net/netlink/af_netlink.c:2533
 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline]
 netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1338
 netlink_sendmsg+0x8de/0xcb0 net/netlink/af_netlink.c:1882
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:733
 __sys_sendto+0x363/0x4c0 net/socket.c:2187
 __do_sys_sendto net/socket.c:2194 [inline]
 __se_sys_sendto net/socket.c:2190 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2190
page last free pid 5550 tgid 5550 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2660
 __slab_free+0x2c2/0x380 mm/slub.c:4520
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4115 [inline]
 slab_alloc_node mm/slub.c:4164 [inline]
 kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4171
 getname_flags+0xb7/0x540 fs/namei.c:139
 do_sys_openat2+0xd2/0x1d0 fs/open.c:1422
 do_sys_open fs/open.c:1443 [inline]
 __do_sys_openat fs/open.c:1459 [inline]
 __se_sys_openat fs/open.c:1454 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1454
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888012a9d380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888012a9d400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888012a9d480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff888012a9d500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888012a9d580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================