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BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x471/0x4b0
Read of size 2 at addr ffff88811bb30c2a by task syz.0.11382/31903

CPU: 1 UID: 0 PID: 31903 Comm: syz.0.11382 Not tainted syzkaller #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:unmap_page_range+0x200b/0x4370
Code: e8 2a c4 19 00 48 8b 84 24 18 01 00 00 49 89 dc 80 3c 18 00 74 08 4c 89 ff e8 a1 c1 19 00 49 8b 1f 48 89 de 48 83 e6 40 31 ff <e8> 20 5d b6 ff 48 83 e3 40 0f 85 e4 06 00 00 49 83 c7 30 4c 89 ff
RSP: 0018:ffffc900087e75e0 EFLAGS: 00000246
RAX: 1ffffd400089a570 RBX: 057ff18000000214 RCX: ffffffff820953c6
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900087e7890 R08: ffffea00044d2b87 R09: 1ffffd400089a570
R10: dffffc0000000000 R11: fffff9400089a571 R12: dffffc0000000000
R13: 00007f6851b6a000 R14: ffffc900087e7aa0 R15: ffffea00044d2b80
 unmap_vmas+0x399/0x580
 exit_mmap+0x248/0xb50
 __mmput+0x118/0x420
 exit_mm+0x1da/0x2c0
 do_exit+0x648/0x2300
 do_group_exit+0x21c/0x2d0
 __x64_sys_exit_group+0x3f/0x40
 x64_sys_call+0x21f7/0x2200
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6851d8ebe9
Code: Unable to access opcode bytes at 0x7f6851d8ebbf.
RSP: 002b:00007ffd9cc6bfe8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6851d8ebe9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffd9cc6c04c R08: 000000059cc6c0df R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000eb7
R13: 00000000000927c0 R14: 0000000000077c0a R15: 00007ffd9cc6c0a0
 </TASK>

Allocated by task 31398:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_node_track_caller_noprof+0x271/0x4e0
 kmemdup_noprof+0x2b/0x70
 addrconf_init_net+0x1c7/0x790
 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 5738:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kfree+0x18e/0x440
 addrconf_exit_net+0x1ab/0x2c0
 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 ffff88811bb30c00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 42 bytes inside of
 freed 512-byte region [ffff88811bb30c00, ffff88811bb30e00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88811bb33800 pfn:0x11bb30
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x57ff00000000240(workingset|head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000240 ffff88801a441c80 ffffea0004710f10 ffffea00044f8e10
raw: ffff88811bb33800 0000000000100008 00000000f5000000 0000000000000000
head: 057ff00000000240 ffff88801a441c80 ffffea0004710f10 ffffea00044f8e10
head: ffff88811bb33800 0000000000100008 00000000f5000000 0000000000000000
head: 057ff00000000002 ffffea00046ecc01 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 13434, tgid 13433 (syz.2.3320), ts 180195985010, free_ts 178622689479
 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_cache_noprof+0x296/0x3d0
 __genradix_ptr_alloc+0x352/0x4a0
 __genradix_prealloc+0x44/0x90
 sctp_stream_init+0x14b/0x440
 sctp_association_new+0x10dd/0x25f0
 sctp_connect_new_asoc+0x2c5/0x690
 __sctp_connect+0x5ba/0xd50
 sctp_getsockopt_connectx3+0x2c4/0x440
 sctp_getsockopt+0x98a/0xb60
 do_sock_getsockopt+0x372/0x450
page last free pid 13341 tgid 13341 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_noprof+0x224/0x4f0
 tomoyo_encode+0x28b/0x550
 tomoyo_path_perm+0x2b3/0x4b0
 tomoyo_path_symlink+0xa3/0xe0
 security_path_symlink+0x177/0x380
 do_symlinkat+0x107/0x3f0
 __x64_sys_symlinkat+0x95/0xb0
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88811bb30b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88811bb30b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88811bb30c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff88811bb30c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88811bb30d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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