syzbot

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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+0x21/0x600 net/l2tp/l2tp_core.c:1561
Write of size 8 at addr ffff888143f8c008 by task kworker/u4:12/3855

CPU: 0 PID: 3855 Comm: kworker/u4:12 Not tainted 6.1.106-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Workqueue: l2tp l2tp_tunnel_del_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:284 [inline]
 print_report+0x15f/0x4f0 mm/kasan/report.c:395
 kasan_report+0x136/0x160 mm/kasan/report.c:495
 kasan_check_range+0x27f/0x290 mm/kasan/generic.c:189
 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+0x21/0x600 net/l2tp/l2tp_core.c:1561
 l2tp_tunnel_closeall net/l2tp/l2tp_core.c:1216 [inline]
 l2tp_tunnel_del_work+0x1ee/0x3b0 net/l2tp/l2tp_core.c:1256
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Allocated by task 4292:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0x97/0xb0 mm/kasan/common.c:383
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 __do_kmalloc_node mm/slab_common.c:955 [inline]
 __kmalloc+0xb2/0x230 mm/slab_common.c:968
 kmalloc include/linux/slab.h:561 [inline]
 kzalloc include/linux/slab.h:692 [inline]
 l2tp_session_create+0x37/0xb30 net/l2tp/l2tp_core.c:1597
 pppol2tp_connect+0xc3d/0x1720 net/l2tp/l2tp_ppp.c:781
 __sys_connect_file net/socket.c:2006 [inline]
 __sys_connect+0x2c9/0x300 net/socket.c:2023
 __do_sys_connect net/socket.c:2033 [inline]
 __se_sys_connect net/socket.c:2030 [inline]
 __x64_sys_connect+0x76/0x80 net/socket.c:2030
 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 15:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516
 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236
 kasan_slab_free include/linux/kasan.h:177 [inline]
 slab_free_hook mm/slub.c:1724 [inline]
 slab_free_freelist_hook mm/slub.c:1750 [inline]
 slab_free mm/slub.c:3661 [inline]
 __kmem_cache_free+0x25c/0x3c0 mm/slub.c:3674
 __sk_destruct+0x50/0x5f0 net/core/sock.c:2139
 rcu_do_batch kernel/rcu/tree.c:2296 [inline]
 rcu_core+0xad5/0x1810 kernel/rcu/tree.c:2556
 handle_softirqs+0x2ee/0xa40 kernel/softirq.c:571
 run_ksoftirqd+0xc6/0x120 kernel/softirq.c:938
 smpboot_thread_fn+0x52c/0xa30 kernel/smpboot.c:164
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Last potentially related work creation:
 kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xb0/0xc0 mm/kasan/generic.c:486
 call_rcu+0x163/0xa10 kernel/rcu/tree.c:2844
 pppol2tp_release+0x247/0x340 net/l2tp/l2tp_ppp.c:457
 __sock_release net/socket.c:654 [inline]
 sock_close+0xcd/0x230 net/socket.c:1400
 __fput+0x3f6/0x8d0 fs/file_table.c:320
 task_work_run+0x246/0x300 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x60/0x270 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 ffff888143f8c000
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 8 bytes inside of
 1024-byte region [ffff888143f8c000, ffff888143f8c400)

The buggy address belongs to the physical page:
page:ffffea00050fe200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x143f88
head:ffffea00050fe200 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x57ff00000010200(slab|head|node=1|zone=2|lastcpupid=0x7ff)
raw: 057ff00000010200 dead000000000100 dead000000000122 ffff888012841dc0
raw: 0000000000000000 0000000000100010 00000001ffffffff 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 3643, tgid 3643 (syz-executor), ts 77901752516, free_ts 35699344323
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2517
 prep_new_page mm/page_alloc.c:2524 [inline]
 get_page_from_freelist+0x322e/0x33b0 mm/page_alloc.c:4290
 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5558
 __alloc_pages_node include/linux/gfp.h:237 [inline]
 alloc_slab_page+0x59/0x150 mm/slub.c:1796
 allocate_slab mm/slub.c:1939 [inline]
 new_slab+0x84/0x2d0 mm/slub.c:1992
 ___slab_alloc+0xc20/0x1270 mm/slub.c:3180
 __slab_alloc mm/slub.c:3279 [inline]
 slab_alloc_node mm/slub.c:3364 [inline]
 __kmem_cache_alloc_node+0x19f/0x260 mm/slub.c:3437
 __do_kmalloc_node mm/slab_common.c:954 [inline]
 __kmalloc_node+0xa2/0x230 mm/slab_common.c:962
 kmalloc_node include/linux/slab.h:582 [inline]
 kvmalloc_node+0x6e/0x180 mm/util.c:581
 kvzalloc_node include/linux/slab.h:713 [inline]
 alloc_shrinker_info+0xe8/0x3d0 mm/vmscan.c:293
 mem_cgroup_css_online+0x28/0x330 mm/memcontrol.c:5380
 online_css+0xba/0x260 kernel/cgroup/cgroup.c:5500
 css_create kernel/cgroup/cgroup.c:5571 [inline]
 cgroup_apply_control_enable+0x7d1/0xae0 kernel/cgroup/cgroup.c:3259
 cgroup_mkdir+0xd8b/0xff0 kernel/cgroup/cgroup.c:5767
 kernfs_iop_mkdir+0x275/0x400 fs/kernfs/dir.c:1221
 vfs_mkdir+0x3b6/0x590 fs/namei.c:4108
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1444 [inline]
 free_pcp_prepare mm/page_alloc.c:1494 [inline]
 free_unref_page_prepare+0xf63/0x1120 mm/page_alloc.c:3369
 free_unref_page+0x33/0x3e0 mm/page_alloc.c:3464
 free_slab mm/slub.c:2031 [inline]
 discard_slab mm/slub.c:2037 [inline]
 __unfreeze_partials+0x1b7/0x210 mm/slub.c:2586
 put_cpu_partial+0x17b/0x250 mm/slub.c:2662
 qlink_free mm/kasan/quarantine.c:168 [inline]
 qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187
 kasan_quarantine_reduce+0x156/0x170 mm/kasan/quarantine.c:294
 __kasan_slab_alloc+0x1f/0x70 mm/kasan/common.c:305
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook+0x52/0x3a0 mm/slab.h:737
 slab_alloc_node mm/slub.c:3398 [inline]
 __kmem_cache_alloc_node+0x137/0x260 mm/slub.c:3437
 __do_kmalloc_node mm/slab_common.c:954 [inline]
 __kmalloc+0xa1/0x230 mm/slab_common.c:968
 kmalloc include/linux/slab.h:561 [inline]
 tomoyo_realpath_from_path+0xcb/0x5d0 security/tomoyo/realpath.c:251
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x29f/0x710 security/tomoyo/file.c:822
 tomoyo_path_symlink+0xda/0x110 security/tomoyo/tomoyo.c:199
 security_path_symlink+0xd9/0x130 security/security.c:1198
 do_symlinkat+0x132/0x390 fs/namei.c:4497
 __do_sys_symlink fs/namei.c:4524 [inline]
 __se_sys_symlink fs/namei.c:4522 [inline]
 __x64_sys_symlink+0x7a/0x90 fs/namei.c:4522

Memory state around the buggy address:
 ffff888143f8bf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888143f8bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888143f8c000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff888143f8c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888143f8c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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