==================================================================
BUG: KASAN: slab-use-after-free in timer_is_static_object+0x80/0x90 kernel/time/timer.c:733
Read of size 8 at addr ffff88807a901ca0 by task syz.1.23344/23262

CPU: 0 UID: 0 PID: 23262 Comm: syz.1.23344 Not tainted 6.12.0-syzkaller-07749-g28eb75e178d3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 timer_is_static_object+0x80/0x90 kernel/time/timer.c:733
 lookup_object_or_alloc.part.0+0x416/0x590 lib/debugobjects.c:679
 lookup_object_or_alloc lib/debugobjects.c:665 [inline]
 debug_object_assert_init+0x268/0x2f0 lib/debugobjects.c:1008
 debug_timer_assert_init kernel/time/timer.c:845 [inline]
 debug_assert_init kernel/time/timer.c:890 [inline]
 __timer_delete+0x81/0x1c0 kernel/time/timer.c:1412
 del_timer include/linux/timer.h:202 [inline]
 try_to_grab_pending+0x7d/0x850 kernel/workqueue.c:2064
 work_grab_pending kernel/workqueue.c:2157 [inline]
 __cancel_work+0xac/0x370 kernel/workqueue.c:4322
 sco_sock_clear_timer+0x4f/0xe0 net/bluetooth/sco.c:180
 sco_sock_close net/bluetooth/sco.c:522 [inline]
 sco_sock_release+0x67/0x2d0 net/bluetooth/sco.c:1298
 __sock_release+0xb0/0x270 net/socket.c:640
 sock_close+0x1c/0x30 net/socket.c:1408
 __fput+0x3f8/0xb60 fs/file_table.c:450
 task_work_run+0x14e/0x250 kernel/task_work.c:239
 get_signal+0x1d3/0x26c0 kernel/signal.c:2789
 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f96dd37e819
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f96de0aa038 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: fffffffffffffffc RBX: 00007f96dd535fa0 RCX: 00007f96dd37e819
RDX: 0000000000000008 RSI: 0000000020001580 RDI: 0000000000000004
RBP: 00007f96dd3f175e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f96dd535fa0 R15: 00007ffcbc3e10f8
 </TASK>

Allocated by task 23070:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
 kmalloc_noprof include/linux/slab.h:879 [inline]
 kzalloc_noprof include/linux/slab.h:1015 [inline]
 sco_conn_add net/bluetooth/sco.c:199 [inline]
 sco_conn_add+0xc8/0x410 net/bluetooth/sco.c:184
 sco_connect net/bluetooth/sco.c:336 [inline]
 sco_sock_connect+0x325/0xbd0 net/bluetooth/sco.c:645
 __sys_connect_file+0x13e/0x1a0 net/socket.c:2055
 __sys_connect+0x14f/0x170 net/socket.c:2074
 __do_sys_connect net/socket.c:2080 [inline]
 __se_sys_connect net/socket.c:2077 [inline]
 __x64_sys_connect+0x72/0xb0 net/socket.c:2077
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 23070:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:2342 [inline]
 slab_free mm/slub.c:4579 [inline]
 kfree+0x14f/0x4b0 mm/slub.c:4727
 sco_conn_free net/bluetooth/sco.c:97 [inline]
 kref_put include/linux/kref.h:65 [inline]
 sco_conn_put+0x2cd/0x4c0 net/bluetooth/sco.c:107
 sco_chan_del+0x9c/0x1b0 net/bluetooth/sco.c:236
 __sco_sock_close+0xab/0x210 net/bluetooth/sco.c:508
 sco_sock_close net/bluetooth/sco.c:523 [inline]
 sco_sock_release+0x6f/0x2d0 net/bluetooth/sco.c:1298
 __sock_release+0xb0/0x270 net/socket.c:640
 sock_close+0x1c/0x30 net/socket.c:1408
 __fput+0x3f8/0xb60 fs/file_table.c:450
 task_work_run+0x14e/0x250 kernel/task_work.c:239
 get_signal+0x1d3/0x26c0 kernel/signal.c:2789
 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88807a901c00
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 160 bytes inside of
 freed 256-byte region [ffff88807a901c00, ffff88807a901d00)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807a900200 pfn:0x7a900
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000240 ffff88801b041b40 ffff88801b040708 ffffea0001d81190
raw: ffff88807a900200 000000000010000a 00000001f5000000 0000000000000000
head: 00fff00000000240 ffff88801b041b40 ffff88801b040708 ffffea0001d81190
head: ffff88807a900200 000000000010000a 00000001f5000000 0000000000000000
head: 00fff00000000001 ffffea0001ea4001 ffffffffffffffff 0000000000000000
head: ffff888000000002 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5848, tgid 5848 (syz-executor), ts 72198926581, free_ts 72169629294
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1556
 prep_new_page mm/page_alloc.c:1564 [inline]
 get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3474
 __alloc_pages_noprof+0x223/0x25a0 mm/page_alloc.c:4751
 alloc_pages_mpol_noprof+0x2c9/0x610 mm/mempolicy.c:2265
 alloc_slab_page mm/slub.c:2412 [inline]
 allocate_slab mm/slub.c:2578 [inline]
 new_slab+0x2c9/0x410 mm/slub.c:2631
 ___slab_alloc+0xdac/0x1880 mm/slub.c:3818
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3908
 __slab_alloc_node mm/slub.c:3961 [inline]
 slab_alloc_node mm/slub.c:4122 [inline]
 __kmalloc_cache_noprof+0x2b4/0x300 mm/slub.c:4290
 kmalloc_noprof include/linux/slab.h:879 [inline]
 kzalloc_noprof include/linux/slab.h:1015 [inline]
 ____ip_mc_inc_group+0x3ee/0x1000 net/ipv4/igmp.c:1468
 __ip_mc_inc_group net/ipv4/igmp.c:1503 [inline]
 ip_mc_inc_group net/ipv4/igmp.c:1509 [inline]
 ip_mc_up+0x154/0x3b0 net/ipv4/igmp.c:1808
 inetdev_event+0xafd/0x18a0 net/ipv4/devinet.c:1638
 notifier_call_chain+0xb9/0x410 kernel/notifier.c:93
 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:1996
 call_netdevice_notifiers_extack net/core/dev.c:2034 [inline]
 call_netdevice_notifiers net/core/dev.c:2048 [inline]
 __dev_notify_flags+0x12d/0x2e0 net/core/dev.c:8982
 dev_change_flags+0x10c/0x160 net/core/dev.c:9020
 do_setlink.constprop.0+0x69c/0x3f70 net/core/rtnetlink.c:3103
page last free pid 5841 tgid 5841 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_unref_page+0x661/0x1080 mm/page_alloc.c:2657
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:247 [inline]
 slab_post_alloc_hook mm/slub.c:4085 [inline]
 slab_alloc_node mm/slub.c:4134 [inline]
 kmem_cache_alloc_noprof+0x121/0x2f0 mm/slub.c:4141
 getname_flags.part.0+0x4c/0x550 fs/namei.c:139
 getname_flags include/linux/audit.h:322 [inline]
 getname+0x8d/0xe0 fs/namei.c:223
 do_sys_openat2+0x104/0x1e0 fs/open.c:1396
 do_sys_open fs/open.c:1417 [inline]
 __do_sys_openat fs/open.c:1433 [inline]
 __se_sys_openat fs/open.c:1428 [inline]
 __x64_sys_openat+0x175/0x210 fs/open.c:1428
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88807a901b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88807a901c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807a901c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff88807a901d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88807a901d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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