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BUG: KASAN: slab-out-of-bounds in __list_add_valid+0x8f/0xb0 lib/list_debug.c:26
Read of size 8 at addr ffff88019c0455d8 by task syz-executor5/21536

CPU: 1 PID: 21536 Comm: syz-executor5 Not tainted 4.18.0-rc2+ #26
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+0x1c9/0x2b4 lib/dump_stack.c:113
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 __list_add_valid+0x8f/0xb0 lib/list_debug.c:26
 __list_add include/linux/list.h:60 [inline]
 list_add_tail include/linux/list.h:93 [inline]
 cma_listen_on_all drivers/infiniband/core/cma.c:2328 [inline]
 rdma_listen+0x6dc/0x990 drivers/infiniband/core/cma.c:3354
 ucma_listen+0x1a4/0x260 drivers/infiniband/core/ucma.c:1096
 ucma_write+0x336/0x420 drivers/infiniband/core/ucma.c:1680
 __vfs_write+0x117/0x9f0 fs/read_write.c:485
 vfs_write+0x1f8/0x560 fs/read_write.c:549
 ksys_write+0x101/0x260 fs/read_write.c:598
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __ia32_sys_write+0x71/0xb0 fs/read_write.c:607
 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline]
 do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7f64cb9
Code: 55 08 8b 88 64 cd ff ff 8b 98 68 cd ff ff 89 c8 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 1c 24 c3 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 
RSP: 002b:00000000f5f600ac EFLAGS: 00000282 ORIG_RAX: 0000000000000004
RAX: ffffffffffffffda RBX: 0000000000000013 RCX: 0000000020000000
RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 4537:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3554
 getname_flags+0xd0/0x5a0 fs/namei.c:140
 getname fs/namei.c:211 [inline]
 user_path_mountpoint_at+0x27/0x40 fs/namei.c:2728
 ksys_umount+0x1c9/0x12e0 fs/namespace.c:1700
 __do_sys_umount fs/namespace.c:1726 [inline]
 __se_sys_umount fs/namespace.c:1724 [inline]
 __ia32_sys_umount+0x53/0x80 fs/namespace.c:1724
 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline]
 do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

Freed by task 4537:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kmem_cache_free+0x86/0x2d0 mm/slab.c:3756
 putname+0xf2/0x130 fs/namei.c:261
 filename_mountpoint+0x35a/0x460 fs/namei.c:2706
 user_path_mountpoint_at+0x37/0x40 fs/namei.c:2728
 ksys_umount+0x1c9/0x12e0 fs/namespace.c:1700
 __do_sys_umount fs/namespace.c:1726 [inline]
 __se_sys_umount fs/namespace.c:1724 [inline]
 __ia32_sys_umount+0x53/0x80 fs/namespace.c:1724
 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline]
 do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

The buggy address belongs to the object at ffff88019c044400
 which belongs to the cache names_cache of size 4096
The buggy address is located 472 bytes to the right of
 4096-byte region [ffff88019c044400, ffff88019c045400)
The buggy address belongs to the page:
page:ffffea0006701100 count:1 mapcount:0 mapping:ffff8801da987dc0 index:0x0 compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffffea000632a788 ffffea00066db988 ffff8801da987dc0
raw: 0000000000000000 ffff88019c044400 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88019c045480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88019c045500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88019c045580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                    ^
 ffff88019c045600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88019c045680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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