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BUG: KASAN: slab-use-after-free in rose_transmit_link+0x5c3/0x740
Read of size 1 at addr ffff888040a9b032 by task syz.2.6716/30248

CPU: 1 UID: 0 PID: 30248 Comm: syz.2.6716 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:
 <TASK>
 dump_stack_lvl+0x189/0x250
 print_report+0xca/0x240
 kasan_report+0x118/0x150
 rose_transmit_link+0x5c3/0x740
 rose_write_internal+0x11dc/0x1ac0
 rose_release+0x24e/0x520
 sock_close+0xc3/0x240
 __fput+0x44c/0xa70
 task_work_run+0x1d4/0x260
 get_signal+0x11ed/0x1340
 arch_do_signal_or_restart+0x9a/0x750
 exit_to_user_mode_loop+0x75/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fef98f8ebe9
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:00007fef971f6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: fffffffffffffe00 RBX: 00007fef991b5fa0 RCX: 00007fef98f8ebe9
RDX: 0000000000000040 RSI: 0000200000000100 RDI: 0000000000000011
RBP: 00007fef99011e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fef991b6038 R14: 00007fef991b5fa0 R15: 00007ffc640c4868
 </TASK>

Allocated by task 30248:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x230/0x3d0
 rose_add_node+0x23a/0xde0
 rose_rt_ioctl+0xa48/0xfb0
 rose_ioctl+0x3ce/0x8b0
 sock_do_ioctl+0xdc/0x300
 sock_ioctl+0x576/0x790
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 30255:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kfree+0x18e/0x440
 rose_rt_device_down+0x473/0x4c0
 rose_device_event+0x603/0x6a0
 notifier_call_chain+0x1b6/0x3e0
 __dev_notify_flags+0x18d/0x2e0
 netif_change_flags+0xe8/0x1a0
 dev_change_flags+0x130/0x260
 dev_ioctl+0x7b4/0x1150
 sock_do_ioctl+0x22c/0x300
 sock_ioctl+0x576/0x790
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888040a9b000
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 50 bytes inside of
 freed 512-byte region [ffff888040a9b000, ffff888040a9b200)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888040a98c00 pfn:0x40a98
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 ffffea00010aee10 ffffea0000ed8e10
raw: ffff888040a98c00 0000000000100009 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88801a441c80 ffffea00010aee10 ffffea0000ed8e10
head: ffff888040a98c00 0000000000100009 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea000102a601 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 29816, tgid 29815 (syz.2.6590), ts 394538223868, free_ts 392318257653
 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_sendmsg+0x155c/0x2810
 __sock_sendmsg+0x19c/0x270
 __sys_sendto+0x3bd/0x520
 __x64_sys_sendto+0xde/0x100
page last free pid 5835 tgid 5835 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
 kmem_cache_alloc_noprof+0x1c1/0x3c0
 mas_dup_build+0x154/0xfe0
 __mt_dup+0x137/0x220
 dup_mmap+0x3c5/0x1ac0
 copy_mm+0x13c/0x4b0
 copy_process+0x1706/0x3c00
 kernel_clone+0x21e/0x840
 __x64_sys_clone+0x18b/0x1e0
 do_syscall_64+0xfa/0x3b0

Memory state around the buggy address:
 ffff888040a9af00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888040a9af80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888040a9b000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff888040a9b080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888040a9b100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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