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BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x471/0x4b0
Read of size 2 at addr ffff888027b07c2a by task syz.2.7065/21929

CPU: 1 UID: 0 PID: 21929 Comm: syz.2.7065 Not tainted 6.16.0-syzkaller-06574-gd9104cec3e8f #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <IRQ>
 dump_stack_lvl+0x189/0x250
 print_report+0xca/0x240
 kasan_report+0x118/0x150
 rose_timer_expiry+0x471/0x4b0
 call_timer_fn+0x17e/0x5f0
 __run_timer_base+0x61a/0x860
 run_timer_softirq+0xb7/0x180
 handle_softirqs+0x286/0x870
 __irq_exit_rcu+0xca/0x1f0
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:lockdep_unregister_key+0x2c5/0x310
Code: 65 48 8b 05 9d 6a fc 10 48 3b 44 24 10 0f 84 26 fe ff ff e8 5d 32 d2 09 e8 88 33 d2 09 41 f7 c7 00 02 00 00 74 bd fb 40 84 ed <75> bc eb cd 90 0f 0b 90 e9 19 ff ff ff 90 0f 0b 90 e9 2a ff ff ff
RSP: 0018:ffffc9000323f998 EFLAGS: 00000246
RAX: 0ed879f9621c2400 RBX: ffff888020e76298 RCX: 0ed879f9621c2400
RDX: ffffffff935dc358 RSI: ffffffff8d98cba8 RDI: ffffffff8be30a00
RBP: ffff888020e76200 R08: 0000000000000000 R09: ffffffff81aa7ed8
R10: dffffc0000000000 R11: fffffbfff1f40f5f R12: 0000000000000000
R13: 0000000000001000 R14: 0000000000000000 R15: 0000000000000206
 __qdisc_destroy+0x166/0x420
 dev_shutdown+0x93/0x440
 unregister_netdevice_many_notify+0xe0f/0x1ff0
 unregister_netdevice_queue+0x33c/0x380
 __tun_detach+0xda4/0x1560
 tun_chr_close+0x10a/0x1c0
 __fput+0x44c/0xa70
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xec/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff29978eb69
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:00007ffeda329d28 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 000000000004986e RCX: 00007ff29978eb69
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007ff2999b7ba0 R08: 0000000000000001 R09: 00000008da32a01f
R10: 00007ff299600000 R11: 0000000000000246 R12: 00007ff2999b5fac
R13: 00007ff2999b5fa0 R14: ffffffffffffffff R15: 00007ffeda329e40
 </TASK>

Allocated by task 21600:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x230/0x3d0
 cfmuxl_create+0x4c/0x1c0
 cfcnfg_create+0x79/0x380
 caif_init_net+0x81/0xc0
 ops_init+0x35c/0x5c0
 setup_net+0x10c/0x320
 copy_net_ns+0x31b/0x4d0
 create_new_namespaces+0x3f3/0x720
 unshare_nsproxy_namespaces+0x11c/0x170
 ksys_unshare+0x4c8/0x8c0
 __x64_sys_unshare+0x38/0x50
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5869:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x62/0x70
 kfree+0x18e/0x440
 cfcnfg_remove+0x5e/0xa0
 caif_exit_net+0x480/0x4a0
 ops_undo_list+0x49a/0x990
 cleanup_net+0x4c5/0x800
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30

The buggy address belongs to the object at ffff888027b07c00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 42 bytes inside of
 freed 512-byte region [ffff888027b07c00, ffff888027b07e00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888027b04000 pfn:0x27b04
head: order:2 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 ffff88801a441c80 ffff88801a4407c8 ffffea0000c09610
raw: ffff888027b04000 000000000010000b 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88801a441c80 ffff88801a4407c8 ffffea0000c09610
head: ffff888027b04000 000000000010000b 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea00009ec101 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
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 1, tgid 1 (swapper/0), ts 21334093193, free_ts 0
 post_alloc_hook+0x240/0x2a0
 get_page_from_freelist+0x21e4/0x22c0
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 allocate_slab+0x8a/0x3b0
 ___slab_alloc+0xbfc/0x1480
 __kmalloc_noprof+0x305/0x4f0
 public_key_verify_signature+0x291/0x8f0
 x509_check_for_self_signed+0x327/0x430
 x509_cert_parse+0x63d/0x7b0
 x509_key_preparse+0x64/0x780
 asymmetric_key_preparse+0xb3/0x160
 __key_create_or_update+0x370/0xa30
 key_create_or_update+0x42/0x60
 x509_load_certificate_list+0x145/0x280
 load_builtin_regdb_keys+0xaf/0xe0
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888027b07b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888027b07b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888027b07c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff888027b07c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888027b07d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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