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BUG: KASAN: slab-out-of-bounds in __list_add_valid+0x9a/0xa0 lib/list_debug.c:26
Read of size 8 at addr ffff88808c0d8ad8 by task syz-executor.4/18866

CPU: 0 PID: 18866 Comm: syz-executor.4 Not tainted 4.14.168-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x142/0x197 lib/dump_stack.c:58
 print_address_description.cold+0x7c/0x1dc mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0xa9/0x2af mm/kasan/report.c:393
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430
 __list_add_valid+0x9a/0xa0 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:2321 [inline]
 rdma_listen+0x5a7/0x840 drivers/infiniband/core/cma.c:3319
 ucma_listen+0x10e/0x170 drivers/infiniband/core/ucma.c:1078
 ucma_write+0x231/0x310 drivers/infiniband/core/ucma.c:1672
 __vfs_write+0x105/0x6b0 fs/read_write.c:480
 vfs_write+0x198/0x500 fs/read_write.c:544
 SYSC_write fs/read_write.c:590 [inline]
 SyS_write+0xfd/0x230 fs/read_write.c:582
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45b349
RSP: 002b:00007fa80a18ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fa80a18f6d4 RCX: 000000000045b349
RDX: 0000000000000010 RSI: 0000000020000140 RDI: 0000000000000008
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000c84 R14: 00000000004cd5d6 R15: 000000000075bf2c

Allocated by task 8051:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x45/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc mm/kasan/kasan.c:551 [inline]
 kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:529
 kasan_slab_alloc+0xf/0x20 mm/kasan/kasan.c:489
 kmem_cache_alloc+0x12e/0x780 mm/slab.c:3552
 getname_flags fs/namei.c:138 [inline]
 getname_flags+0xcb/0x580 fs/namei.c:128
 user_path_at_empty+0x2f/0x50 fs/namei.c:2630
 SYSC_readlinkat fs/stat.c:394 [inline]
 SyS_readlinkat fs/stat.c:382 [inline]
 SYSC_readlink fs/stat.c:421 [inline]
 SyS_readlink+0xb7/0x290 fs/stat.c:418
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Freed by task 8051:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x45/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x75/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kmem_cache_free+0x83/0x2b0 mm/slab.c:3758
 putname+0xdb/0x120 fs/namei.c:259
 filename_lookup+0x23a/0x380 fs/namei.c:2385
 user_path_at_empty+0x43/0x50 fs/namei.c:2630
 SYSC_readlinkat fs/stat.c:394 [inline]
 SyS_readlinkat fs/stat.c:382 [inline]
 SYSC_readlink fs/stat.c:421 [inline]
 SyS_readlink+0xb7/0x290 fs/stat.c:418
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

The buggy address belongs to the object at ffff88808c0d8e00
 which belongs to the cache names_cache of size 4096
The buggy address is located 808 bytes to the left of
 4096-byte region [ffff88808c0d8e00, ffff88808c0d9e00)
The buggy address belongs to the page:
page:ffffea0002303600 count:1 mapcount:0 mapping:ffff88808c0d8e00 index:0x0 compound_mapcount: 0
flags: 0xfffe0000008100(slab|head)
raw: 00fffe0000008100 ffff88808c0d8e00 0000000000000000 0000000100000001
raw: ffffea0001556020 ffffea0001733ca0 ffff8880aa9e9cc0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808c0d8980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88808c0d8a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88808c0d8a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                    ^
 ffff88808c0d8b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88808c0d8b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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