==================================================================
BUG: KASAN: use-after-free in trace_event_raw_event_mm_filemap_op_page_cache+0x3c6/0x3f0 include/trace/events/filemap.h:-1
Read of size 4 at addr ffff88812097c010 by task syz.3.4266/13783

CPU: 1 PID: 13783 Comm: syz.3.4266 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:88
 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:427 [inline]
 kasan_report+0x10f/0x150 mm/kasan/report.c:444
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308
 trace_event_raw_event_mm_filemap_op_page_cache+0x3c6/0x3f0 include/trace/events/filemap.h:-1
 trace_mm_filemap_delete_from_page_cache include/trace/events/filemap.h:47 [inline]
 __delete_from_page_cache+0x418/0x470 mm/filemap.c:238
 __remove_mapping+0x601/0x990 mm/vmscan.c:1216
 shrink_page_list+0x2a24/0x5800 mm/vmscan.c:1829
 shrink_inactive_list mm/vmscan.c:2338 [inline]
 shrink_list mm/vmscan.c:2583 [inline]
 shrink_lruvec+0x1297/0x3a40 mm/vmscan.c:5800
 shrink_node_memcgs mm/vmscan.c:5992 [inline]
 shrink_node+0x11ee/0x2a40 mm/vmscan.c:6022
 shrink_zones mm/vmscan.c:6228 [inline]
 do_try_to_free_pages+0x5a7/0x1580 mm/vmscan.c:6286
 try_to_free_mem_cgroup_pages+0x261/0x610 mm/vmscan.c:6600
 mem_cgroup_force_empty mm/memcontrol.c:3595 [inline]
 mem_cgroup_force_empty_write+0x130/0x170 mm/memcontrol.c:3616
 cgroup_file_write+0x294/0x560 kernel/cgroup/cgroup.c:4011
 kernfs_fop_write_iter+0x2bd/0x400 fs/kernfs/file.c:296
 call_write_iter include/linux/fs.h:2212 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x831/0xfd0 fs/read_write.c:594
 ksys_write+0x14a/0x260 fs/read_write.c:647
 __do_sys_write fs/read_write.c:659 [inline]
 __se_sys_write fs/read_write.c:656 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:656
 x64_sys_call+0x8ef/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:2
 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
RIP: 0033:0x7f581c805159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f581b25e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f581ca8cfa0 RCX: 00007f581c805159
RDX: 0000000000000001 RSI: 00002000000002c0 RDI: 0000000000000008
RBP: 00007f581c89c06b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f581ca8d038 R14: 00007f581ca8cfa0 R15: 00007ffd7bffdd78
 </TASK>

Allocated by task 13242:
 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 mm/kasan/common.c:512 [inline]
 __kasan_kmalloc+0xd4/0x100 mm/kasan/common.c:521
 kasan_kmalloc include/linux/kasan.h:227 [inline]
 __kmalloc+0x13d/0x2c0 mm/slub.c:4436
 __kmalloc_node include/linux/slab.h:487 [inline]
 kmalloc_node include/linux/slab.h:642 [inline]
 kvmalloc_node+0x211/0x320 mm/util.c:621
 kvmalloc include/linux/mm.h:862 [inline]
 kvmalloc_array include/linux/mm.h:880 [inline]
 alloc_fdtable+0x10b/0x2e0 fs/file.c:150
 dup_fd+0x896/0xad0 fs/file.c:345
 copy_files+0x76/0xe0 kernel/fork.c:1631
 copy_process+0x1080/0x3230 kernel/fork.c:2343
 kernel_clone+0x233/0x960 kernel/fork.c:2744
 __do_sys_clone kernel/fork.c:2870 [inline]
 __se_sys_clone kernel/fork.c:2854 [inline]
 __x64_sys_clone+0x198/0x210 kernel/fork.c:2854
 x64_sys_call+0x41f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:57
 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 13599:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4a/0x70 mm/kasan/common.c:45
 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370
 ____kasan_slab_free+0x125/0x160 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:1728 [inline]
 slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1754
 slab_free mm/slub.c:3526 [inline]
 kfree+0xc4/0x270 mm/slub.c:4588
 kvfree+0x35/0x40 mm/util.c:661
 __free_fdtable fs/file.c:36 [inline]
 put_files_struct+0x27a/0x320 fs/file.c:430
 exit_files+0x80/0xa0 fs/file.c:443
 do_exit+0xb39/0x29a0 kernel/exit.c:891
 do_group_exit+0x149/0x310 kernel/exit.c:1010
 get_signal+0x64f/0x1430 kernel/signal.c:2916
 arch_do_signal_or_restart+0xe2/0x1100 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0xa7/0xe0 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x1a/0x30 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+0x3a/0x60 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348
 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358
 __call_rcu_common kernel/rcu/tree.c:3011 [inline]
 call_rcu+0x10b/0xf60 kernel/rcu/tree.c:3129
 in6_dev_finish_destroy+0x163/0x1b0 net/ipv6/addrconf_core.c:278
 in6_dev_put include/net/addrconf.h:421 [inline]
 addrconf_ifdown+0x16c7/0x1910 net/ipv6/addrconf.c:3965
 addrconf_notify+0x3bd/0xe00 net/ipv6/addrconf.c:-1
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0x90/0x100 kernel/notifier.c:391
 call_netdevice_notifiers_info net/core/dev.c:2070 [inline]
 call_netdevice_notifiers_extack net/core/dev.c:2082 [inline]
 call_netdevice_notifiers net/core/dev.c:2096 [inline]
 unregister_netdevice_many+0x103d/0x1a00 net/core/dev.c:11176
 ip_tunnel_delete_nets+0x343/0x390 net/ipv4/ip_tunnel.c:1123
 ipgre_tap_exit_batch_net+0x22/0x30 net/ipv4/ip_gre.c:1724
 ops_exit_list net/core/net_namespace.c:177 [inline]
 cleanup_net+0x605/0xae0 net/core/net_namespace.c:599
 process_one_work+0x6c8/0xbb0 kernel/workqueue.c:2328
 worker_thread+0xaa0/0x1250 kernel/workqueue.c:2475
 kthread+0x3f5/0x4f0 kernel/kthread.c:337
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

Second to last potentially related work creation:
 kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348
 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358
 insert_work+0x51/0x310 kernel/workqueue.c:1373
 __queue_work+0x8e1/0xc60 kernel/workqueue.c:1539
 queue_work_on+0xde/0x150 kernel/workqueue.c:1566
 queue_work include/linux/workqueue.h:510 [inline]
 schedule_work include/linux/workqueue.h:571 [inline]
 destroy_super_rcu+0xd1/0xe0 fs/super.c:172
 rcu_do_batch+0x4c1/0xbf0 kernel/rcu/tree.c:2523
 rcu_core+0x4a3/0xef0 kernel/rcu/tree.c:2763
 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2776
 handle_softirqs+0x250/0x560 kernel/softirq.c:583
 run_ksoftirqd+0x28/0x40 kernel/softirq.c:959
 smpboot_thread_fn+0x446/0x880 kernel/smpboot.c:164
 kthread+0x3f5/0x4f0 kernel/kthread.c:337
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

The buggy address belongs to the object at ffff88812097c000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 16 bytes inside of
 2048-byte region [ffff88812097c000, ffff88812097c800)
The buggy address belongs to the page:
page:ffffea0004825e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x120978
head:ffffea0004825e00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head|zone=1)
raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100043200
raw: 0000000000000000 0000000000080008 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 8745, ts 565676088477, free_ts 565662791674
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2607
 prep_new_page+0x1c/0x110 mm/page_alloc.c:2613
 get_page_from_freelist+0x2c3a/0x2cd0 mm/page_alloc.c:4487
 __alloc_pages+0x1a2/0x460 mm/page_alloc.c:5824
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1937 [inline]
 new_slab+0xa0/0x4d0 mm/slub.c:2000
 ___slab_alloc+0x3ac/0x840 mm/slub.c:3033
 __slab_alloc+0x49/0x90 mm/slub.c:3120
 slab_alloc_node mm/slub.c:3211 [inline]
 slab_alloc mm/slub.c:3255 [inline]
 kmem_cache_alloc_trace+0x146/0x270 mm/slub.c:3272
 kmalloc include/linux/slab.h:619 [inline]
 kzalloc include/linux/slab.h:750 [inline]
 keypair_create drivers/net/wireguard/noise.c:100 [inline]
 wg_noise_handshake_begin_session+0xd5/0x740 drivers/net/wireguard/noise.c:827
 wg_packet_send_handshake_response+0x135/0x230 drivers/net/wireguard/send.c:96
 wg_receive_handshake_packet drivers/net/wireguard/receive.c:161 [inline]
 wg_packet_handshake_receive_worker+0x512/0x910 drivers/net/wireguard/receive.c:220
 process_one_work+0x6c8/0xbb0 kernel/workqueue.c:2328
 worker_thread+0xaa0/0x1250 kernel/workqueue.c:2475
 kthread+0x3f5/0x4f0 kernel/kthread.c:337
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1474 [inline]
 free_pcp_prepare mm/page_alloc.c:1546 [inline]
 free_unref_page_prepare+0x5fa/0x600 mm/page_alloc.c:3536
 free_unref_page+0xae/0x540 mm/page_alloc.c:3618
 free_the_page mm/page_alloc.c:805 [inline]
 __free_pages+0x6c/0x100 mm/page_alloc.c:5900
 __free_slab+0xe5/0x1e0 mm/slub.c:2025
 free_slab mm/slub.c:2040 [inline]
 discard_slab mm/slub.c:2046 [inline]
 __unfreeze_partials+0x15a/0x190 mm/slub.c:2532
 put_cpu_partial+0xc6/0x120 mm/slub.c:2612
 __slab_free+0x1d4/0x290 mm/slub.c:3395
 do_slab_free mm/slub.c:3514 [inline]
 ___cache_free+0x104/0x120 mm/slub.c:3535
 qlink_free+0x4d/0x90 mm/kasan/quarantine.c:157
 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x14a/0x170 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xe0 mm/kasan/common.c:443
 kasan_slab_alloc include/linux/kasan.h:217 [inline]
 slab_post_alloc_hook+0x4f/0x2b0 mm/slab.h:550
 slab_alloc_node mm/slub.c:3245 [inline]
 slab_alloc mm/slub.c:3255 [inline]
 kmem_cache_alloc+0xf7/0x260 mm/slub.c:3260
 kmem_cache_zalloc include/linux/slab.h:740 [inline]
 jbd2_alloc_handle include/linux/jbd2.h:1597 [inline]
 new_handle fs/jbd2/transaction.c:477 [inline]
 jbd2__journal_start+0x13d/0x6e0 fs/jbd2/transaction.c:504
 __ext4_journal_start_sb+0xfb/0x2b0 fs/ext4/ext4_jbd2.c:105

Memory state around the buggy address:
 ffff88812097bf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88812097bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88812097c000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff88812097c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88812097c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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