==================================================================
BUG: KASAN: use-after-free in ax25_heartbeat_expiry+0x10c/0x130 net/ax25/ax25_timer.c:125
Read of size 4 at addr ffff888019dcf050 by task kworker/u5:0/146
CPU: 0 PID: 146 Comm: kworker/u5:0 Not tainted 5.15.186-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: hci5 hci_rx_work
Call Trace:
<IRQ>
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
print_address_description+0x60/0x2d0 mm/kasan/report.c:248
__kasan_report mm/kasan/report.c:434 [inline]
kasan_report+0xdf/0x130 mm/kasan/report.c:451
ax25_heartbeat_expiry+0x10c/0x130 net/ax25/ax25_timer.c:125
call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451
expire_timers kernel/time/timer.c:1496 [inline]
__run_timers+0x525/0x7c0 kernel/time/timer.c:1767
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
handle_softirqs+0x328/0x820 kernel/softirq.c:576
__do_softirq kernel/softirq.c:610 [inline]
invoke_softirq kernel/softirq.c:450 [inline]
__irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:dump_stack_lvl+0x1d0/0x230 lib/dump_stack.c:108
Code: e8 35 18 d6 f7 49 21 de 75 61 e8 4b 14 d6 f7 4d 85 ed 75 07 e8 41 14 d6 f7 eb 06 e8 3a 14 d6 f7 fb 48 c7 44 24 20 0e 36 e0 45 <4b> c7 04 27 00 00 00 00 43 c7 44 27 09 00 00 00 00 66 43 c7 44 27
RSP: 0018:ffffc900016cf2e0 EFLAGS: 00000293
RAX: ffffffff89a1aed6 RBX: 0000000000000082 RCX: ffff888017bfd940
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900016cf3d0 R08: dffffc0000000000 R09: fffffbfff1ff7436
R10: fffffbfff1ff7436 R11: 1ffffffff1ff7435 R12: dffffc0000000000
R13: 0000000000000200 R14: 0000000000000000 R15: 1ffff920002d9e60
sysfs_warn_dup fs/sysfs/dir.c:30 [inline]
sysfs_create_dir_ns+0x252/0x280 fs/sysfs/dir.c:64
create_dir lib/kobject.c:89 [inline]
kobject_add_internal+0x662/0xd00 lib/kobject.c:263
kobject_add_varg lib/kobject.c:398 [inline]
kobject_add+0x152/0x210 lib/kobject.c:450
device_add+0x483/0xfb0 drivers/base/core.c:3347
hci_conn_add_sysfs+0xd1/0x1e0 net/bluetooth/hci_sysfs.c:46
le_conn_complete_evt+0xcbc/0x1590 net/bluetooth/hci_event.c:5406
hci_le_conn_complete_evt net/bluetooth/hci_event.c:5454 [inline]
hci_le_meta_evt+0x289/0x3b80 net/bluetooth/hci_event.c:6176
hci_event_packet+0xe05/0x12f0 net/bluetooth/hci_event.c:6525
hci_rx_work+0x255/0xa10 net/bluetooth/hci_core.c:5160
process_one_work+0x863/0x1000 kernel/workqueue.c:2310
worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
Allocated by task 5231:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
____kasan_kmalloc mm/kasan/common.c:513 [inline]
__kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522
kmalloc include/linux/slab.h:604 [inline]
kzalloc include/linux/slab.h:735 [inline]
ax25_dev_device_up+0x50/0x580 net/ax25/ax25_dev.c:55
ax25_device_event+0x483/0x4f0 net/ax25/af_ax25.c:139
notifier_call_chain kernel/notifier.c:83 [inline]
raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391
call_netdevice_notifiers_extack net/core/dev.c:2061 [inline]
call_netdevice_notifiers net/core/dev.c:2075 [inline]
__dev_notify_flags+0x178/0x2d0 net/core/dev.c:-1
dev_change_flags+0xe3/0x1a0 net/core/dev.c:8929
dev_ifsioc+0x147/0xe70 net/core/dev_ioctl.c:324
dev_ioctl+0x55f/0xe50 net/core/dev_ioctl.c:587
sock_do_ioctl+0x222/0x2f0 net/socket.c:1154
sock_ioctl+0x4ed/0x6e0 net/socket.c:1257
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
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
Freed by task 7721:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_hook mm/slub.c:1705 [inline]
slab_free_freelist_hook+0xea/0x170 mm/slub.c:1731
slab_free mm/slub.c:3499 [inline]
kfree+0xef/0x2a0 mm/slub.c:4559
ax25_dev_put include/net/ax25.h:302 [inline]
ax25_release+0x661/0x870 net/ax25/af_ax25.c:1062
__sock_release net/socket.c:649 [inline]
sock_close+0xd5/0x240 net/socket.c:1336
__fput+0x234/0x930 fs/file_table.c:311
task_work_run+0x125/0x1a0 kernel/task_work.c:188
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
Last potentially related work creation:
kasan_save_stack+0x35/0x60 mm/kasan/common.c:38
kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348
insert_work+0x54/0x3d0 kernel/workqueue.c:1366
__queue_work+0x9c5/0xd50 kernel/workqueue.c:1532
queue_work_on+0x11d/0x1d0 kernel/workqueue.c:1559
inet6addr_event+0x9c/0xc0 drivers/infiniband/core/roce_gid_mgmt.c:883
notifier_call_chain kernel/notifier.c:83 [inline]
atomic_notifier_call_chain+0x15d/0x280 kernel/notifier.c:198
addrconf_ifdown+0xdf4/0x1970 net/ipv6/addrconf.c:3906
addrconf_notify+0x445/0xf00 net/ipv6/addrconf.c:-1
notifier_call_chain kernel/notifier.c:83 [inline]
raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391
call_netdevice_notifiers_extack net/core/dev.c:2061 [inline]
call_netdevice_notifiers net/core/dev.c:2075 [inline]
dev_close_many+0x28d/0x400 net/core/dev.c:1650
unregister_netdevice_many+0x472/0x18f0 net/core/dev.c:11110
default_device_exit_batch+0x336/0x390 net/core/dev.c:11667
ops_exit_list net/core/net_namespace.c:177 [inline]
cleanup_net+0x77b/0xb80 net/core/net_namespace.c:635
process_one_work+0x863/0x1000 kernel/workqueue.c:2310
worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Second to last potentially related work creation:
kasan_save_stack+0x35/0x60 mm/kasan/common.c:38
kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348
insert_work+0x54/0x3d0 kernel/workqueue.c:1366
__queue_work+0x9c5/0xd50 kernel/workqueue.c:1532
queue_work_on+0x11d/0x1d0 kernel/workqueue.c:1559
queue_work include/linux/workqueue.h:512 [inline]
netdevice_queue_work drivers/infiniband/core/roce_gid_mgmt.c:659 [inline]
netdevice_event+0x803/0x900 drivers/infiniband/core/roce_gid_mgmt.c:802
notifier_call_chain kernel/notifier.c:83 [inline]
raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391
call_netdevice_notifiers_extack net/core/dev.c:2061 [inline]
call_netdevice_notifiers net/core/dev.c:2075 [inline]
register_netdevice+0x1275/0x16b0 net/core/dev.c:10428
ip6gre_newlink_common+0x39a/0x530 net/ipv6/ip6_gre.c:2005
ip6gre_newlink+0x1d4/0x530 net/ipv6/ip6_gre.c:2036
__rtnl_newlink net/core/rtnetlink.c:3524 [inline]
rtnl_newlink+0x114c/0x17d0 net/core/rtnetlink.c:3572
rtnetlink_rcv_msg+0x9b9/0xe60 net/core/rtnetlink.c:5650
netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2489
netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline]
netlink_unicast+0x77c/0x920 net/netlink/af_netlink.c:1337
netlink_sendmsg+0x8ab/0xbc0 net/netlink/af_netlink.c:1905
sock_sendmsg_nosec net/socket.c:704 [inline]
__sock_sendmsg net/socket.c:716 [inline]
__sys_sendto+0x423/0x580 net/socket.c:2063
__do_sys_sendto net/socket.c:2075 [inline]
__se_sys_sendto net/socket.c:2071 [inline]
__x64_sys_sendto+0xda/0xf0 net/socket.c:2071
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 ffff888019dcf000
which belongs to the cache kmalloc-192 of size 192
The buggy address is located 80 bytes inside of
192-byte region [ffff888019dcf000, ffff888019dcf0c0)
The buggy address belongs to the page:
page:ffffea00006773c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x19dcf
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea0000902ec0 0000000200000002 ffff888016841a00
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 1, ts 2719394485, free_ts 0
prep_new_page mm/page_alloc.c:2426 [inline]
get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192
__alloc_pages+0x1e1/0x470 mm/page_alloc.c:5474
alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2031
alloc_slab_page mm/slub.c:1775 [inline]
allocate_slab mm/slub.c:1912 [inline]
new_slab+0xc0/0x4b0 mm/slub.c:1975
___slab_alloc+0x81e/0xdf0 mm/slub.c:3008
__slab_alloc mm/slub.c:3095 [inline]
slab_alloc_node mm/slub.c:3186 [inline]
slab_alloc mm/slub.c:3228 [inline]
kmem_cache_alloc_trace+0x1a5/0x2a0 mm/slub.c:3245
kmalloc include/linux/slab.h:604 [inline]
kzalloc include/linux/slab.h:735 [inline]
call_usermodehelper_setup+0x8a/0x260 kernel/umh.c:365
kobject_uevent_env+0x65e/0x890 lib/kobject_uevent.c:629
kernel_add_sysfs_param+0xfb/0x120 kernel/params.c:816
param_sysfs_builtin+0x164/0x1e0 kernel/params.c:851
param_sysfs_init+0x66/0x70 kernel/params.c:972
do_one_initcall+0x1ee/0x680 init/main.c:1302
do_initcall_level+0x137/0x1f0 init/main.c:1375
do_initcalls+0x4b/0x90 init/main.c:1391
kernel_init_freeable+0x3ce/0x560 init/main.c:1615
kernel_init+0x19/0x1b0 init/main.c:1506
page_owner free stack trace missing
Memory state around the buggy address:
ffff888019dcef00: 06 fc fc fc fc 05 fc fc fc fc 05 fc fc fc fc 06
ffff888019dcef80: fc fc fc fc 04 fc fc fc fc 04 fc fc fc fc fc fc
>ffff888019dcf000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888019dcf080: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff888019dcf100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
----------------
Code disassembly (best guess):
0: e8 35 18 d6 f7 call 0xf7d6183a
5: 49 21 de and %rbx,%r14
8: 75 61 jne 0x6b
a: e8 4b 14 d6 f7 call 0xf7d6145a
f: 4d 85 ed test %r13,%r13
12: 75 07 jne 0x1b
14: e8 41 14 d6 f7 call 0xf7d6145a
19: eb 06 jmp 0x21
1b: e8 3a 14 d6 f7 call 0xf7d6145a
20: fb sti
21: 48 c7 44 24 20 0e 36 movq $0x45e0360e,0x20(%rsp)
28: e0 45
* 2a: 4b c7 04 27 00 00 00 movq $0x0,(%r15,%r12,1) <-- trapping instruction
31: 00
32: 43 c7 44 27 09 00 00 movl $0x0,0x9(%r15,%r12,1)
39: 00 00
3b: 66 data16
3c: 43 rex.XB
3d: c7 .byte 0xc7
3e: 44 27 rex.R (bad)