Message-ID: <94eb2c054604ad40010568e8ea21@google.com>
Date:   Mon, 02 Apr 2018 20:01:02 -0700
From:   syzbot <syzbot+6956235342b7317ec564@...kaller.appspotmail.com>
To:     dasaratharaman.chandramouli@...el.com, dledford@...hat.com,
        jgg@...pe.ca, leonro@...lanox.com, linux-kernel@...r.kernel.org,
        linux-rdma@...r.kernel.org, markb@...lanox.com, monis@...lanox.com,
        parav@...lanox.com, syzkaller-bugs@...glegroups.com
Subject: KASAN: use-after-free Read in cma_cancel_operation

Hello,

syzbot hit the following crash on upstream commit
86bbbebac1933e6e95e8234c4f7d220c5ddd38bc (Mon Apr 2 18:47:07 2018 +0000)
Merge branch 'ras-core-for-linus' of  
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
syzbot dashboard link:  
https://syzkaller.appspot.com/bug?extid=6956235342b7317ec564

So far this crash happened 4 times on upstream.
C reproducer: https://syzkaller.appspot.com/x/repro.c?id=6621340819783680
syzkaller reproducer:  
https://syzkaller.appspot.com/x/repro.syz?id=6075521074987008
Raw console output:  
https://syzkaller.appspot.com/x/log.txt?id=6447569127342080
Kernel config:  
https://syzkaller.appspot.com/x/.config?id=6801295859785128502
compiler: gcc (GCC) 7.1.1 20170620

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+6956235342b7317ec564@...kaller.appspotmail.com
It will help syzbot understand when the bug is fixed. See footer for  
details.
If you forward the report, please keep this part and the footer.

==================================================================
BUG: KASAN: use-after-free in __list_del_entry_valid+0x144/0x150  
lib/list_debug.c:54
Read of size 8 at addr ffff8801d8dc7d20 by task syzkaller468166/4496

CPU: 0 PID: 4496 Comm: syzkaller468166 Not tainted 4.16.0+ #376
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+0x1a7/0x27d lib/dump_stack.c:53
  print_address_description+0x73/0x250 mm/kasan/report.c:256
  kasan_report_error mm/kasan/report.c:354 [inline]
  kasan_report+0x23c/0x360 mm/kasan/report.c:412
  __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
  __list_del_entry_valid+0x144/0x150 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:1569 [inline]
  cma_cancel_operation+0x455/0xd60 drivers/infiniband/core/cma.c:1597
  rdma_destroy_id+0xff/0xda0 drivers/infiniband/core/cma.c:1661
  ucma_close+0x100/0x2f0 drivers/infiniband/core/ucma.c:1735
  __fput+0x327/0x7f0 fs/file_table.c:209
  ____fput+0x15/0x20 fs/file_table.c:243
  task_work_run+0x1ab/0x280 kernel/task_work.c:113
  exit_task_work include/linux/task_work.h:22 [inline]
  do_exit+0x1986/0x2700 kernel/exit.c:865
  do_group_exit+0x149/0x400 kernel/exit.c:968
  get_signal+0x74c/0x16e0 kernel/signal.c:2469
  do_signal+0x90/0x1e90 arch/x86/kernel/signal.c:809
  exit_to_usermode_loop+0x258/0x2f0 arch/x86/entry/common.c:162
  prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
  syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
  do_syscall_64+0x6ec/0x940 arch/x86/entry/common.c:292
  entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446b09
RSP: 002b:00007f2b89150da8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00000000006e29fc RCX: 0000000000446b09
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000006e29fc
RBP: 00000000006e29f8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 006d635f616d6472
R13: 2f646e6162696e69 R14: 666e692f7665642f R15: 0000000000000005

Allocated by task 4493:
  save_stack+0x43/0xd0 mm/kasan/kasan.c:447
  set_track mm/kasan/kasan.c:459 [inline]
  kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:552
  kmem_cache_alloc_trace+0x136/0x740 mm/slab.c:3608
  kmalloc include/linux/slab.h:512 [inline]
  kzalloc include/linux/slab.h:701 [inline]
  rdma_create_id+0xd0/0x640 drivers/infiniband/core/cma.c:787
  ucma_create_id+0x35f/0x920 drivers/infiniband/core/ucma.c:480
  ucma_write+0x2d6/0x3d0 drivers/infiniband/core/ucma.c:1656
  __vfs_write+0xef/0x970 fs/read_write.c:480
  vfs_write+0x189/0x510 fs/read_write.c:544
  SYSC_write fs/read_write.c:589 [inline]
  SyS_write+0xef/0x220 fs/read_write.c:581
  do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x42/0xb7

Freed by task 4496:
  save_stack+0x43/0xd0 mm/kasan/kasan.c:447
  set_track mm/kasan/kasan.c:459 [inline]
  __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:520
  kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:527
  __cache_free mm/slab.c:3486 [inline]
  kfree+0xd9/0x260 mm/slab.c:3801
  rdma_destroy_id+0x821/0xda0 drivers/infiniband/core/cma.c:1691
  ucma_close+0x100/0x2f0 drivers/infiniband/core/ucma.c:1735
  __fput+0x327/0x7f0 fs/file_table.c:209
  ____fput+0x15/0x20 fs/file_table.c:243
  task_work_run+0x1ab/0x280 kernel/task_work.c:113
  exit_task_work include/linux/task_work.h:22 [inline]
  do_exit+0x1986/0x2700 kernel/exit.c:865
  do_group_exit+0x149/0x400 kernel/exit.c:968
  get_signal+0x74c/0x16e0 kernel/signal.c:2469
  do_signal+0x90/0x1e90 arch/x86/kernel/signal.c:809
  exit_to_usermode_loop+0x258/0x2f0 arch/x86/entry/common.c:162
  prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
  syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
  do_syscall_64+0x6ec/0x940 arch/x86/entry/common.c:292
  entry_SYSCALL_64_after_hwframe+0x42/0xb7

The buggy address belongs to the object at ffff8801d8dc7b40
  which belongs to the cache kmalloc-1024 of size 1024
The buggy address is located 480 bytes inside of
  1024-byte region [ffff8801d8dc7b40, ffff8801d8dc7f40)
The buggy address belongs to the page:
page:ffffea0007637180 count:1 mapcount:0 mapping:ffff8801d8dc6040 index:0x0  
compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffff8801d8dc6040 0000000000000000 0000000100000007
raw: ffffea0007635ea0 ffff8801dac01848 ffff8801dac00ac0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
  ffff8801d8dc7c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8801d8dc7c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff8801d8dc7d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                ^
  ffff8801d8dc7d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8801d8dc7e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
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