==================================================================
BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
BUG: KASAN: use-after-free in test_and_set_bit include/asm-generic/bitops/instrumented-atomic.h:70 [inline]
BUG: KASAN: use-after-free in l2tp_session_delete+0x24/0x4e0 net/l2tp/l2tp_core.c:1552
Write of size 8 at addr ffff888117111008 by task kworker/u4:5/519
CPU: 1 PID: 519 Comm: kworker/u4:5 Tainted: G W 5.15.149-syzkaller-00144-g19f346d27871 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Workqueue: l2tp l2tp_tunnel_del_work
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106
print_address_description+0x87/0x3b0 mm/kasan/report.c:248
__kasan_report mm/kasan/report.c:427 [inline]
kasan_report+0x179/0x1c0 mm/kasan/report.c:444
kasan_check_range+0x293/0x2a0 mm/kasan/generic.c:189
__kasan_check_write+0x14/0x20 mm/kasan/shadow.c:37
instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
test_and_set_bit include/asm-generic/bitops/instrumented-atomic.h:70 [inline]
l2tp_session_delete+0x24/0x4e0 net/l2tp/l2tp_core.c:1552
l2tp_tunnel_closeall net/l2tp/l2tp_core.c:1207 [inline]
l2tp_tunnel_del_work+0x19d/0x380 net/l2tp/l2tp_core.c:1247
process_one_work+0x6bb/0xc10 kernel/workqueue.c:2325
worker_thread+0xad5/0x12a0 kernel/workqueue.c:2472
kthread+0x421/0x510 kernel/kthread.c:337
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
Allocated by task 21358:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track mm/kasan/common.c:45 [inline]
set_alloc_info mm/kasan/common.c:433 [inline]
____kasan_kmalloc+0xdb/0x110 mm/kasan/common.c:512
__kasan_kmalloc+0x9/0x10 mm/kasan/common.c:521
kasan_kmalloc include/linux/kasan.h:227 [inline]
__kmalloc+0x13a/0x270 mm/slub.c:4427
kmalloc include/linux/slab.h:608 [inline]
kzalloc include/linux/slab.h:733 [inline]
l2tp_session_create+0x38/0xb60 net/l2tp/l2tp_core.c:1588
pppol2tp_connect+0xc5d/0x1690 net/l2tp/l2tp_ppp.c:782
__sys_connect_file net/socket.c:1918 [inline]
__sys_connect+0x38b/0x410 net/socket.c:1935
__do_sys_connect net/socket.c:1945 [inline]
__se_sys_connect net/socket.c:1942 [inline]
__x64_sys_connect+0x7a/0x90 net/socket.c:1942
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x61/0xcb
Freed by task 21356:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:45
kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370
____kasan_slab_free+0x126/0x160 mm/kasan/common.c:365
__kasan_slab_free+0x11/0x20 mm/kasan/common.c:373
kasan_slab_free include/linux/kasan.h:193 [inline]
slab_free_hook mm/slub.c:1723 [inline]
slab_free_freelist_hook+0xbd/0x190 mm/slub.c:1749
slab_free mm/slub.c:3519 [inline]
kfree+0xc8/0x220 mm/slub.c:4579
l2tp_session_free net/l2tp/l2tp_core.c:163 [inline]
l2tp_session_dec_refcount+0xa9/0x1b0 net/l2tp/l2tp_core.c:200
pppol2tp_session_destruct+0xaf/0xf0 net/l2tp/l2tp_ppp.c:419
__sk_destruct+0x56/0x5b0 net/core/sock.c:1950
sk_destruct net/core/sock.c:1995 [inline]
__sk_free+0x36c/0x470 net/core/sock.c:2006
sk_free+0x51/0x80 net/core/sock.c:2017
sock_put include/net/sock.h:1914 [inline]
pppol2tp_put_sk+0x77/0xb0 net/l2tp/l2tp_ppp.c:402
rcu_do_batch+0x57a/0xc10 kernel/rcu/tree.c:2523
rcu_core+0x517/0x1020 kernel/rcu/tree.c:2763
rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2776
__do_softirq+0x26d/0x5bf kernel/softirq.c:565
Last potentially related work creation:
kasan_save_stack+0x3b/0x60 mm/kasan/common.c:38
__kasan_record_aux_stack+0xd3/0xf0 mm/kasan/generic.c:348
kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358
__call_rcu_common kernel/rcu/tree.c:3007 [inline]
call_rcu+0x135/0x1310 kernel/rcu/tree.c:3125
pppol2tp_release+0x20f/0x2d0 net/l2tp/l2tp_ppp.c:458
__sock_release net/socket.c:649 [inline]
sock_close+0xdf/0x270 net/socket.c:1336
__fput+0x3fe/0x910 fs/file_table.c:280
____fput+0x15/0x20 fs/file_table.c:308
task_work_run+0x129/0x190 kernel/task_work.c:164
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop+0xc4/0xe0 kernel/entry/common.c:175
exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:208
__syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
syscall_exit_to_user_mode+0x26/0x160 kernel/entry/common.c:301
do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x61/0xcb
Second to last potentially related work creation:
kasan_save_stack+0x3b/0x60 mm/kasan/common.c:38
__kasan_record_aux_stack+0xd3/0xf0 mm/kasan/generic.c:348
kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358
kvfree_call_rcu+0xb1/0x8b0 kernel/rcu/tree.c:3644
drop_sysctl_table+0x311/0x450 fs/proc/proc_sysctl.c:1682
drop_sysctl_table+0x323/0x450 fs/proc/proc_sysctl.c:1685
unregister_sysctl_table+0x7b/0x120 fs/proc/proc_sysctl.c:1720
unregister_net_sysctl_table+0x15/0x20 net/sysctl_net.c:175
neigh_sysctl_unregister+0x78/0x90 net/core/neighbour.c:3732
devinet_sysctl_unregister net/ipv4/devinet.c:2630 [inline]
inetdev_destroy net/ipv4/devinet.c:325 [inline]
inetdev_event+0x7c6/0x10a0 net/ipv4/devinet.c:1599
notifier_call_chain kernel/notifier.c:83 [inline]
raw_notifier_call_chain+0x8c/0xf0 kernel/notifier.c:391
call_netdevice_notifiers_info net/core/dev.c:2025 [inline]
call_netdevice_notifiers_extack net/core/dev.c:2037 [inline]
call_netdevice_notifiers net/core/dev.c:2051 [inline]
unregister_netdevice_many+0xe0a/0x17c0 net/core/dev.c:11105
default_device_exit_batch+0x38a/0x3f0 net/core/dev.c:11638
ops_exit_list net/core/net_namespace.c:174 [inline]
cleanup_net+0x6ce/0xc00 net/core/net_namespace.c:596
process_one_work+0x6bb/0xc10 kernel/workqueue.c:2325
worker_thread+0xad5/0x12a0 kernel/workqueue.c:2472
kthread+0x421/0x510 kernel/kthread.c:337
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
The buggy address belongs to the object at ffff888117111000
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 8 bytes inside of
512-byte region [ffff888117111000, ffff888117111200)
The buggy address belongs to the page:
page:ffffea00045c4400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x117110
head:ffffea00045c4400 order:2 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head|zone=1)
raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100042f00
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 172, ts 6191974795, free_ts 0
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0x1a3/0x1b0 mm/page_alloc.c:2604
prep_new_page+0x1b/0x110 mm/page_alloc.c:2610
get_page_from_freelist+0x3550/0x35d0 mm/page_alloc.c:4484
__alloc_pages+0x27e/0x8f0 mm/page_alloc.c:5776
allocate_slab mm/slub.c:1932 [inline]
new_slab+0x9a/0x4e0 mm/slub.c:1995
___slab_alloc+0x39e/0x830 mm/slub.c:3028
__slab_alloc+0x4a/0x90 mm/slub.c:3115
slab_alloc_node mm/slub.c:3206 [inline]
slab_alloc mm/slub.c:3248 [inline]
kmem_cache_alloc_trace+0x142/0x210 mm/slub.c:3265
kmalloc include/linux/slab.h:603 [inline]
kzalloc include/linux/slab.h:733 [inline]
alloc_bprm+0x59/0x760 fs/exec.c:1530
do_execveat_common+0x193/0x710 fs/exec.c:1916
do_execve fs/exec.c:2035 [inline]
__do_sys_execve fs/exec.c:2111 [inline]
__se_sys_execve fs/exec.c:2106 [inline]
__x64_sys_execve+0x92/0xb0 fs/exec.c:2106
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x61/0xcb
page_owner free stack trace missing
Memory state around the buggy address:
ffff888117110f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888117110f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888117111000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888117111080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888117111100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 519 at lib/refcount.c:28 refcount_warn_saturate+0x158/0x1a0 lib/refcount.c:28
Modules linked in:
CPU: 0 PID: 519 Comm: kworker/u4:5 Tainted: G B W 5.15.149-syzkaller-00144-g19f346d27871 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Workqueue: l2tp l2tp_tunnel_del_work
RIP: 0010:refcount_warn_saturate+0x158/0x1a0 lib/refcount.c:28
Code: 04 01 48 c7 c7 40 d0 82 85 e8 24 51 dc fe 0f 0b eb 8b e8 eb 0f 0b ff c6 05 13 56 9e 04 01 48 c7 c7 a0 d0 82 85 e8 08 51 dc fe <0f> 0b e9 6c ff ff ff e8 cc 0f 0b ff c6 05 f5 55 9e 04 01 48 c7 c7
RSP: 0018:ffffc90000c57c20 EFLAGS: 00010246
RAX: 7065f4df410fb500 RBX: 0000000000000003 RCX: ffff8881122f93c0
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc90000c57c30 R08: ffffffff815760e5 R09: ffffed103ee065e8
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888117112420
R13: ffff888117112400 R14: 0000000000000003 R15: ffff888117111088
FS: 0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc0e179000 CR3: 000000010c4c2000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__refcount_sub_and_test include/linux/refcount.h:283 [inline]
__refcount_dec_and_test include/linux/refcount.h:315 [inline]
refcount_dec_and_test include/linux/refcount.h:333 [inline]
l2tp_session_dec_refcount+0xc4/0x1b0 net/l2tp/l2tp_core.c:199
l2tp_session_delete+0x3bc/0x4e0 net/l2tp/l2tp_core.c:1561