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BUG: KASAN: use-after-free in __list_del_entry_valid+0xdc/0xf5 lib/list_debug.c:54
Read of size 8 at addr ffff88809011aea8 by task syz-executor.5/32379

CPU: 0 PID: 32379 Comm: syz-executor.5 Not tainted 5.0.0-rc6-next-20190214 #35
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132
 __list_del_entry_valid+0xdc/0xf5 lib/list_debug.c:54
 __list_del_entry include/linux/list.h:117 [inline]
 list_del include/linux/list.h:125 [inline]
 cma_cancel_listens drivers/infiniband/core/cma.c:1726 [inline]
 cma_cancel_operation drivers/infiniband/core/cma.c:1754 [inline]
 cma_cancel_operation+0x2d7/0xa10 drivers/infiniband/core/cma.c:1742
 rdma_destroy_id+0x8d/0xab0 drivers/infiniband/core/cma.c:1818
 ucma_close+0x115/0x320 drivers/infiniband/core/ucma.c:1777
 __fput+0x2e5/0x8d0 fs/file_table.c:278
 ____fput+0x16/0x20 fs/file_table.c:309
 task_work_run+0x14a/0x1c0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x90a/0x2fa0 kernel/exit.c:876
 do_group_exit+0x135/0x370 kernel/exit.c:980
 __do_sys_exit_group kernel/exit.c:991 [inline]
 __se_sys_exit_group kernel/exit.c:989 [inline]
 __x64_sys_exit_group+0x44/0x50 kernel/exit.c:989
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457e29
Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffdd0f0da98 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000000000000000b RCX: 0000000000457e29
RDX: 0000000000411c71 RSI: 0000000000a54ef0 RDI: 0000000000000000
RBP: 00000000004bd560 R08: 000000000000000c R09: 00007ffdd0f0dba0
R10: 0000000001045940 R11: 0000000000000246 R12: 000000000073bfac
R13: 0000000000000001 R14: 0000000000000004 R15: 000000000073bfac

Allocated by task 32387:
 save_stack+0x45/0xd0 mm/kasan/common.c:75
 set_track mm/kasan/common.c:87 [inline]
 __kasan_kmalloc mm/kasan/common.c:497 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:470
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:511
 kmem_cache_alloc_trace+0x151/0x760 mm/slab.c:3615
 kmalloc include/linux/slab.h:548 [inline]
 kzalloc include/linux/slab.h:743 [inline]
 __rdma_create_id+0x5f/0x4e0 drivers/infiniband/core/cma.c:879
 ucma_create_id+0x1de/0x640 drivers/infiniband/core/ucma.c:506
 ucma_write+0x2da/0x3c0 drivers/infiniband/core/ucma.c:1696
 __vfs_write+0x8d/0x110 fs/read_write.c:485
 vfs_write+0x20c/0x580 fs/read_write.c:549
 ksys_write+0xea/0x1f0 fs/read_write.c:598
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:607
 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 32386:
 save_stack+0x45/0xd0 mm/kasan/common.c:75
 set_track mm/kasan/common.c:87 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:459
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:467
 __cache_free mm/slab.c:3491 [inline]
 kfree+0xcf/0x230 mm/slab.c:3816
 rdma_destroy_id+0x723/0xab0 drivers/infiniband/core/cma.c:1853
 ucma_close+0x115/0x320 drivers/infiniband/core/ucma.c:1777
 __fput+0x2e5/0x8d0 fs/file_table.c:278
 ____fput+0x16/0x20 fs/file_table.c:309
 task_work_run+0x14a/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:166
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
 do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff88809011acc0
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 488 bytes inside of
 2048-byte region [ffff88809011acc0, ffff88809011b4c0)
The buggy address belongs to the page:
page:ffffea0002404680 count:1 mapcount:0 mapping:ffff88812c3f0c40 index:0x0 compound_mapcount: 0
flags: 0x1fffc0000010200(slab|head)
raw: 01fffc0000010200 ffffea00021c3708 ffffea0002a0f988 ffff88812c3f0c40
raw: 0000000000000000 ffff88809011a440 0000000100000003 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809011ad80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88809011ae00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88809011ae80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff88809011af00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88809011af80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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