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BUG: KASAN: slab-use-after-free in rose_transmit_link+0x5c3/0x740
Read of size 1 at addr ffff88803ca9a832 by task syz.1.2937/16768

CPU: 0 UID: 0 PID: 16768 Comm: syz.1.2937 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: 0033:0x7f69e618ebe9
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:00007f69e7005038 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: fffffffffffffe00 RBX: 00007f69e63b6090 RCX: 00007f69e618ebe9
RDX: 000000000000001c RSI: 0000200000000040 RDI: 000000000000000e
RBP: 00007f69e6211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f69e63b6128 R14: 00007f69e63b6090 R15: 00007ffd00055fb8
 </TASK>

Allocated by task 16767:
 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 16788:
 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
 netif_close_many+0x29c/0x410
 netif_close+0x158/0x210
 dev_close+0x10a/0x220
 bpq_device_event+0x377/0x6a0
 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 ffff88803ca9a800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 50 bytes inside of
 freed 512-byte region [ffff88803ca9a800, ffff88803ca9aa00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3ca98
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801a441c80 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801a441c80 dead000000000100 dead000000000122
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0000f2a601 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 0x252800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_THISNODE), pid 16492, tgid 16491 (syz.2.2855), ts 245714982697, free_ts 245583371015
 post_alloc_hook+0x240/0x2a0
 get_page_from_freelist+0x21e4/0x22c0
 __alloc_frozen_pages_noprof+0x181/0x370
 allocate_slab+0x65/0x370
 ___slab_alloc+0xbeb/0x1410
 __kmalloc_node_noprof+0x2fd/0x4e0
 blk_alloc_flush_queue+0xe2/0x230
 blk_mq_alloc_and_init_hctx+0x679/0xd60
 __blk_mq_realloc_hw_ctxs+0x169/0x400
 blk_mq_init_allocated_queue+0x400/0x1490
 __blk_mq_alloc_disk+0x1f0/0x340
 nbd_dev_add+0x46c/0xae0
 nbd_genl_connect+0x919/0x18f0
 genl_family_rcv_msg_doit+0x215/0x300
 genl_rcv_msg+0x60e/0x790
 netlink_rcv_skb+0x208/0x470
page last free pid 10160 tgid 10160 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 free_large_kmalloc+0x13a/0x1f0
 ops_undo_list+0x856/0x990
 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

Memory state around the buggy address:
 ffff88803ca9a700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88803ca9a780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88803ca9a800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff88803ca9a880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88803ca9a900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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