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BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x471/0x4b0
Read of size 2 at addr ffff888101296c2a by task syz.0.12981/25788

CPU: 1 UID: 0 PID: 25788 Comm: syz.0.12981 Not tainted 6.16.0-syzkaller-12063-g37816488247d #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:ida_alloc_range+0x4/0x840
Code: b4 f6 e9 23 ff ff ff e8 3a 01 0a 00 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <55> 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec 20 01
RSP: 0018:ffffc9000466f7a0 EFLAGS: 00000246
RAX: ffffffff825ad8c7 RBX: dffffc0000000000 RCX: 0000000000000cc0
RDX: 000000000fffffff RSI: 0000000000000000 RDI: ffffffff8e2bf800
RBP: 1ffff11023b0aedf R08: 0000000000000003 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1007e9da51 R12: ffff88810f349500
R13: 1ffff11023b0ae00 R14: ffff88810f349500 R15: ffff88803f4ed280
 proc_register+0x3f/0x500
 snmp6_register_dev+0xc3/0x140
 ipv6_add_dev+0x73e/0x1370
 addrconf_notify+0x794/0x1010
 notifier_call_chain+0x1b6/0x3e0
 register_netdevice+0x1608/0x1ae0
 register_netdev+0x40/0x60
 vti6_init_net+0x238/0x370
 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
RIP: 0033:0x7f31a578ebe9
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:00007f31a6598038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f31a59b5fa0 RCX: 00007f31a578ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006a040000
RBP: 00007f31a5811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f31a59b6038 R14: 00007f31a59b5fa0 R15: 00007ffc7173a2d8
 </TASK>

Allocated by task 25625:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x230/0x3d0
 ip_vs_control_net_init+0x275/0x1900
 __ip_vs_init+0x2d2/0x460
 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 23:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kfree+0x18e/0x440
 rcu_core+0xcab/0x1770
 handle_softirqs+0x286/0x870
 run_ksoftirqd+0x9b/0x100
 smpboot_thread_fn+0x542/0xa60
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60
 kasan_record_aux_stack+0xbd/0xd0
 call_rcu+0x157/0x9c0
 __ip_vs_cleanup_batch+0x8b/0x100
 ops_undo_list+0x525/0x990
 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 ffff888101296c00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 42 bytes inside of
 freed 512-byte region [ffff888101296c00, ffff888101296e00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x101294
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000040 ffff88801a441c80 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 057ff00000000040 ffff88801a441c80 0000000000000000 dead000000000001
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 057ff00000000002 ffffea000404a501 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 16196, tgid 16195 (syz.3.10466), ts 860450266863, free_ts 824635334192
 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/0x370
 ___slab_alloc+0xbeb/0x1410
 __kmalloc_noprof+0x305/0x4f0
 copy_splice_read+0x143/0x9b0
 splice_direct_to_actor+0x4d0/0xcc0
 do_splice_direct+0x181/0x270
 do_sendfile+0x4da/0x7e0
 __se_sys_sendfile64+0x13e/0x190
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 16240 tgid 16240 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 __put_partials+0x156/0x1a0
 put_cpu_partial+0x17c/0x250
 __slab_free+0x2d5/0x3c0
 qlist_free_all+0x97/0x140
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 __kmalloc_node_noprof+0x21b/0x4e0
 __vmalloc_node_range_noprof+0x5a9/0x12f0
 __vmalloc_node_noprof+0xc2/0x110
 dup_task_struct+0x3e7/0x860
 copy_process+0x54b/0x3c00
 kernel_clone+0x21e/0x840
 user_mode_thread+0xdd/0x140
 call_usermodehelper_exec_work+0x9c/0x230
 process_scheduled_works+0xae1/0x17b0

Memory state around the buggy address:
 ffff888101296b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888101296b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888101296c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff888101296c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888101296d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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