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BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x471/0x4b0
Read of size 2 at addr ffff888115e6e42a by task syz.1.2494/12814

CPU: 0 UID: 0 PID: 12814 Comm: syz.1.2494 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:lock_acquire+0x175/0x360
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 eb 93 02 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90003e4f2c0 EFLAGS: 00000206
RAX: c2ef2384e01d0400 RBX: 0000000000000000 RCX: c2ef2384e01d0400
RDX: 0000000000000000 RSI: ffffffff8dba3961 RDI: ffffffff8be32680
RBP: ffffffff825d53a2 R08: 0000000000000000 R09: ffffffff825d53a2
R10: dffffc0000000000 R11: ffffed102001c024 R12: 0000000000000000
R13: ffff8881000e0188 R14: 0000000000000001 R15: 0000000000000246
 down_write+0x96/0x1f0
 kernfs_add_one+0x2c2/0x520
 __kernfs_create_file+0x22b/0x2e0
 sysfs_add_file_mode_ns+0x238/0x300
 internal_create_group+0x66d/0x1110
 sysfs_create_groups+0x59/0x120
 kobject_add_internal+0x5e6/0xb40
 kobject_add+0x155/0x220
 ib_setup_port_attrs+0xd6d/0x2070
 add_one_compat_dev+0x3d6/0x5c0
 rdma_dev_init_net+0x1dd/0x270
 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: 0033:0x7f82c218ebe9
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:00007f82c300e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f82c23b6090 RCX: 00007f82c218ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000062040200
RBP: 00007f82c2211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f82c23b6128 R14: 00007f82c23b6090 R15: 00007ffe1f812b28
 </TASK>

Allocated by task 11394:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_node_noprof+0x276/0x4e0
 allocate_slab+0x16a/0x370
 ___slab_alloc+0xbeb/0x1410
 kmem_cache_alloc_noprof+0x283/0x3c0
 __send_signal_locked+0x22a/0xeb0
 force_sig_info_to_task+0x30c/0x590
 force_sig_fault+0xdc/0x130
 exc_page_fault+0x76/0xf0
 asm_exc_page_fault+0x26/0x30

Freed by task 5785:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kfree+0x18e/0x440
 __free_slab+0xb0/0x1a0
 __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
 kmem_cache_alloc_node_noprof+0x1bb/0x3c0
 __alloc_skb+0x112/0x2d0
 tcp_stream_alloc_skb+0x3d/0x340
 tcp_sendmsg_locked+0xf38/0x5620
 tcp_sendmsg+0x2f/0x50
 __sock_sendmsg+0x19c/0x270
 sock_write_iter+0x258/0x330
 vfs_write+0x54b/0xa90
 ksys_write+0x145/0x250
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888115e6e400
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 42 bytes inside of
 freed 512-byte region [ffff888115e6e400, ffff888115e6e600)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x115e6c
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000040 ffff88801a441c80 ffffea00043f9700 dead000000000002
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 057ff00000000040 ffff88801a441c80 ffffea00043f9700 dead000000000002
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 057ff00000000002 ffffea0004579b01 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 5841, tgid 5841 (syz-executor), ts 51453454055, 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/0x370
 ___slab_alloc+0xbeb/0x1410
 __kmalloc_noprof+0x305/0x4f0
 fib6_info_alloc+0x30/0xf0
 ip6_route_info_create+0x142/0x860
 addrconf_f6i_alloc+0x1d2/0x450
 ipv6_add_addr+0x56e/0x1090
 addrconf_add_linklocal+0x28c/0x6c0
 addrconf_addr_gen+0x490/0x580
 addrconf_init_auto_addrs+0x62d/0xa30
 addrconf_notify+0xacc/0x1010
 notifier_call_chain+0x1b6/0x3e0
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888115e6e300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888115e6e380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888115e6e400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff888115e6e480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888115e6e500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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