==================================================================
BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
BUG: KASAN: use-after-free in test_and_set_bit include/asm-generic/bitops/instrumented-atomic.h:71 [inline]
BUG: KASAN: use-after-free in l2tp_session_delete+0x27/0x520 net/l2tp/l2tp_core.c:1561
Write of size 8 at addr ffff888128e81008 by task kworker/u4:3/322
CPU: 1 PID: 322 Comm: kworker/u4:3 Tainted: G W 6.1.124-syzkaller-00114-g2055772eada0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
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 mm/kasan/report.c:316 [inline]
print_report+0x158/0x4e0 mm/kasan/report.c:427
kasan_report+0x13c/0x170 mm/kasan/report.c:531
kasan_check_range+0x294/0x2a0 mm/kasan/generic.c:189
__kasan_check_write+0x14/0x20 mm/kasan/shadow.c:37
instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
test_and_set_bit include/asm-generic/bitops/instrumented-atomic.h:71 [inline]
l2tp_session_delete+0x27/0x520 net/l2tp/l2tp_core.c:1561
l2tp_tunnel_closeall net/l2tp/l2tp_core.c:1216 [inline]
l2tp_tunnel_del_work+0x1f8/0x400 net/l2tp/l2tp_core.c:1256
process_one_work+0x73d/0xcb0 kernel/workqueue.c:2299
worker_thread+0xa60/0x1260 kernel/workqueue.c:2446
kthread+0x26d/0x300 kernel/kthread.c:386
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Allocated by task 14031:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505
____kasan_kmalloc mm/kasan/common.c:379 [inline]
__kasan_kmalloc+0x9c/0xb0 mm/kasan/common.c:388
kasan_kmalloc include/linux/kasan.h:212 [inline]
__do_kmalloc_node mm/slab_common.c:938 [inline]
__kmalloc+0xb4/0x1e0 mm/slab_common.c:951
kmalloc include/linux/slab.h:568 [inline]
kzalloc include/linux/slab.h:699 [inline]
l2tp_session_create+0x38/0xbe0 net/l2tp/l2tp_core.c:1597
pppol2tp_connect+0xc5d/0x1690 net/l2tp/l2tp_ppp.c:781
__sys_connect_file net/socket.c:2001 [inline]
__sys_connect+0x2c9/0x300 net/socket.c:2018
__do_sys_connect net/socket.c:2028 [inline]
__se_sys_connect net/socket.c:2025 [inline]
__x64_sys_connect+0x7a/0x90 net/socket.c:2025
x64_sys_call+0x14e/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:43
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Freed by task 14036:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:516
____kasan_slab_free+0x131/0x180 mm/kasan/common.c:241
__kasan_slab_free+0x11/0x20 mm/kasan/common.c:249
kasan_slab_free include/linux/kasan.h:178 [inline]
slab_free_hook mm/slub.c:1745 [inline]
slab_free_freelist_hook mm/slub.c:1771 [inline]
slab_free mm/slub.c:3686 [inline]
__kmem_cache_free+0x21d/0x410 mm/slub.c:3702
kfree+0x7a/0xf0 mm/slab_common.c:990
l2tp_session_free net/l2tp/l2tp_core.c:168 [inline]
l2tp_session_dec_refcount+0xa9/0x1b0 net/l2tp/l2tp_core.c:205
pppol2tp_session_destruct+0xaf/0xf0 net/l2tp/l2tp_ppp.c:418
__sk_destruct+0x56/0x5c0 net/core/sock.c:2148
sk_destruct net/core/sock.c:2193 [inline]
__sk_free+0x36c/0x470 net/core/sock.c:2204
sk_free+0x51/0x80 net/core/sock.c:2215
sock_put include/net/sock.h:2049 [inline]
pppol2tp_put_sk+0x77/0xb0 net/l2tp/l2tp_ppp.c:401
rcu_do_batch+0x552/0xbe0 kernel/rcu/tree.c:2297
rcu_core+0x502/0xf40 kernel/rcu/tree.c:2557
rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2574
handle_softirqs+0x1db/0x650 kernel/softirq.c:617
__do_softirq+0xb/0xd kernel/softirq.c:655
Last potentially related work creation:
kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45
__kasan_record_aux_stack+0xb4/0xc0 mm/kasan/generic.c:486
kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496
__call_rcu_common kernel/rcu/tree.c:2807 [inline]
call_rcu+0xdc/0x10f0 kernel/rcu/tree.c:2926
pppol2tp_release+0x20f/0x2d0 net/l2tp/l2tp_ppp.c:457
__sock_release net/socket.c:652 [inline]
sock_close+0xdf/0x270 net/socket.c:1390
__fput+0x1e5/0x870 fs/file_table.c:320
____fput+0x15/0x20 fs/file_table.c:348
task_work_run+0x24d/0x2e0 kernel/task_work.c:203
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0x94/0xa0 kernel/entry/common.c:177
exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x26/0x130 kernel/entry/common.c:303
do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
The buggy address belongs to the object at ffff888128e81000
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 8 bytes inside of
512-byte region [ffff888128e81000, ffff888128e81200)
The buggy address belongs to the physical page:
page:ffffea0004a3a000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x128e80
head:ffffea0004a3a000 order:2 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head|zone=1)
raw: 4000000000010200 ffffea000461f900 dead000000000003 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 0x1d2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 13, tgid 13 (ksoftirqd/0), ts 687771357366, free_ts 680589985947
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0x213/0x220 mm/page_alloc.c:2605
prep_new_page+0x1b/0x110 mm/page_alloc.c:2612
get_page_from_freelist+0x2f41/0x2fc0 mm/page_alloc.c:4477
__alloc_pages+0x234/0x610 mm/page_alloc.c:5775
alloc_slab_page+0x6c/0xf0
allocate_slab mm/slub.c:1962 [inline]
new_slab+0x90/0x3e0 mm/slub.c:2015
___slab_alloc+0x6f9/0xb80 mm/slub.c:3203
__slab_alloc+0x5d/0xa0 mm/slub.c:3302
slab_alloc_node mm/slub.c:3387 [inline]
__kmem_cache_alloc_node+0x207/0x2a0 mm/slub.c:3462
__do_kmalloc_node mm/slab_common.c:937 [inline]
__kmalloc_node_track_caller+0xa2/0x1e0 mm/slab_common.c:958
kmalloc_reserve net/core/skbuff.c:446 [inline]
__alloc_skb+0x125/0x2d0 net/core/skbuff.c:515
alloc_skb include/linux/skbuff.h:1290 [inline]
nlmsg_new include/net/netlink.h:991 [inline]
fdb_notify+0x77/0x130 net/bridge/br_fdb.c:191
br_fdb_update+0x505/0x660 net/bridge/br_fdb.c:888
br_handle_frame_finish+0x41a/0x1660 net/bridge/br_input.c:124
nf_hook_bridge_pre net/bridge/br_input.c:282 [inline]
br_handle_frame+0x984/0x1070 net/bridge/br_input.c:406
__netif_receive_skb_core+0x1264/0x43d0 net/core/dev.c:5448
page last free stack trace:
reset_page_owner include/linux/page_owner.h:26 [inline]
free_pages_prepare mm/page_alloc.c:1513 [inline]
free_pcp_prepare mm/page_alloc.c:1587 [inline]
free_unref_page_prepare+0x9f1/0xa00 mm/page_alloc.c:3526
free_unref_page+0xb2/0x5c0 mm/page_alloc.c:3622
free_the_page mm/page_alloc.c:798 [inline]
__free_pages+0x61/0xf0 mm/page_alloc.c:5864
__free_slab+0xce/0x1a0 mm/slub.c:2039
free_slab mm/slub.c:2054 [inline]
discard_slab mm/slub.c:2060 [inline]
__unfreeze_partials+0x165/0x1a0 mm/slub.c:2609
put_cpu_partial+0xa9/0x100 mm/slub.c:2685
__slab_free+0x1c8/0x280 mm/slub.c:3563
do_slab_free mm/slub.c:3640 [inline]
___cache_free+0xc6/0xd0 mm/slub.c:3696
qlink_free mm/kasan/quarantine.c:168 [inline]
qlist_free_all+0xc5/0x140 mm/kasan/quarantine.c:187
kasan_quarantine_reduce+0x15a/0x180 mm/kasan/quarantine.c:294
__kasan_slab_alloc+0x24/0x80 mm/kasan/common.c:310
kasan_slab_alloc include/linux/kasan.h:202 [inline]
slab_post_alloc_hook+0x53/0x2c0 mm/slab.h:768
slab_alloc_node mm/slub.c:3421 [inline]
__kmem_cache_alloc_node+0x193/0x2a0 mm/slub.c:3462
kmalloc_node_trace+0x26/0xb0 mm/slab_common.c:1041
kmalloc_node include/linux/slab.h:585 [inline]
kzalloc_node include/linux/slab.h:710 [inline]
__get_vm_area_node+0x129/0x370 mm/vmalloc.c:2505
__vmalloc_node_range+0x338/0x1560 mm/vmalloc.c:3206
Memory state around the buggy address:
ffff888128e80f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888128e80f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888128e81000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888128e81080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888128e81100: 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: 1 PID: 322 at lib/refcount.c:28 refcount_warn_saturate+0x158/0x1a0 lib/refcount.c:28
Modules linked in:
CPU: 1 PID: 322 Comm: kworker/u4:3 Tainted: G B W 6.1.124-syzkaller-00114-g2055772eada0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Workqueue: l2tp l2tp_tunnel_del_work
RIP: 0010:refcount_warn_saturate+0x158/0x1a0 lib/refcount.c:28
Code: 05 01 48 c7 c7 e0 bf e9 85 e8 34 ed cc fe 0f 0b eb 8b e8 4b c9 fd fe c6 05 0e dc 17 05 01 48 c7 c7 40 c0 e9 85 e8 18 ed cc fe <0f> 0b e9 6c ff ff ff e8 2c c9 fd fe c6 05 f0 db 17 05 01 48 c7 c7
RSP: 0018:ffffc9000dcafc18 EFLAGS: 00010246
RAX: 4147cb3524480600 RBX: 0000000000000003 RCX: ffff888113c4e540
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000dcafc28 R08: ffffffff8144bb2e R09: ffffed103ede4e9c
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888128e81080
R13: ffff888128e81000 R14: 0000000000000003 R15: ffff888128e81088
FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555907564e8 CR3: 000000000700f000 CR4: 00000000003526a0
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:204
l2tp_session_delete+0x407/0x520 net/l2tp/l2tp_core.c:1570
l2tp_tunnel_closeall net/l2tp/l2tp_core.c:1216 [inline]
l2tp_tunnel_del_work+0x1f8/0x400 net/l2tp/l2tp_core.c:1256
process_one_work+0x73d/0xcb0 kernel/workqueue.c:2299
worker_thread+0xa60/0x1260 kernel/workqueue.c:2446
kthread+0x26d/0x300 kernel/kthread.c:386
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
---[ end trace 0000000000000000 ]---