WARNING: bad unlock balance in ucma_destroy

WARNING: bad unlock balance in ucma_destroy_id
Status: upstream: reported syz repro on 2019/07/01 17:24
Reported-by: syzbot+22956fa835c831577177@syzkaller.appspotmail.com
First crash: 141d, last: 141d

similar bugs (2):
Kernel	Title	Repro	Bisected	Count	Last	Reported	Patched	Status
linux-4.19	WARNING: bad unlock balance in ucma_destroy_id	syz		2	146d	146d	0/1	upstream: reported syz repro on 2019/06/27 11:05
upstream	WARNING: bad unlock balance in ucma_destroy_id	syz	cause	34	10d	448d	0/14	upstream: reported syz repro on 2018/08/28 15:20

Sample crash report:

IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready
IPv6: ADDRCONF(NETDEV_UP): vxcan1: link is not ready
8021q: adding VLAN 0 to HW filter on device batadv0
IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready
=====================================
WARNING: bad unlock balance detected!
4.14.131 #25 Not tainted
-------------------------------------
syz-executor.0/7941 is trying to release lock (&file->mut) at:
[<ffffffff84789c6d>] ucma_destroy_id+0x20d/0x420 drivers/infiniband/core/ucma.c:606
but there are no more locks to release!

other info that might help us debug this:
1 lock held by syz-executor.0/7941:
 #0:  (&file->mut){+.+.}, at: [<ffffffff84789c0a>] ucma_destroy_id+0x1aa/0x420 drivers/infiniband/core/ucma.c:604

stack backtrace:
CPU: 1 PID: 7941 Comm: syz-executor.0 Not tainted 4.14.131 #25
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+0x138/0x19c lib/dump_stack.c:53
 print_unlock_imbalance_bug kernel/locking/lockdep.c:3548 [inline]
 print_unlock_imbalance_bug.cold+0x114/0x123 kernel/locking/lockdep.c:3525
 __lock_release kernel/locking/lockdep.c:3762 [inline]
 lock_release+0x616/0x940 kernel/locking/lockdep.c:4010
 __mutex_unlock_slowpath+0x71/0x800 kernel/locking/mutex.c:1018
 mutex_unlock+0xd/0x10 kernel/locking/mutex.c:614
 ucma_destroy_id+0x20d/0x420 drivers/infiniband/core/ucma.c:606
 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: 0033:0x459519
RSP: 002b:00007f5ffff83c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459519
RDX: 0000000020000118 RSI: 0000000020000100 RDI: 0000000000000003
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5ffff846d4
R13: 00000000004d0138 R14: 00000000004e02c8 R15: 00000000ffffffff
==================================================================
BUG: KASAN: use-after-free in ucma_destroy_id+0x3e2/0x420 drivers/infiniband/core/ucma.c:608
Read of size 8 at addr ffff888089d48128 by task syz-executor.0/7941

CPU: 1 PID: 7941 Comm: syz-executor.0 Not tainted 4.14.131 #25
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+0x138/0x19c lib/dump_stack.c:53
 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
 ucma_destroy_id+0x3e2/0x420 drivers/infiniband/core/ucma.c:608
 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: 0033:0x459519
RSP: 002b:00007f5ffff83c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459519
RDX: 0000000020000118 RSI: 0000000020000100 RDI: 0000000000000003
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5ffff846d4
R13: 00000000004d0138 R14: 00000000004e02c8 R15: 00000000ffffffff

Allocated by task 7937:
 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
 kmem_cache_alloc_trace+0x152/0x790 mm/slab.c:3618
 kmalloc include/linux/slab.h:488 [inline]
 kzalloc include/linux/slab.h:661 [inline]
 ucma_alloc_ctx+0x85/0x520 drivers/infiniband/core/ucma.c:192
 ucma_create_id+0xed/0x5b0 drivers/infiniband/core/ucma.c:478
 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

Freed by task 7936:
 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]
 kfree+0xcc/0x270 mm/slab.c:3815
 ucma_free_ctx+0x73c/0xa30 drivers/infiniband/core/ucma.c:577
 ucma_close+0x11d/0x310 drivers/infiniband/core/ucma.c:1758
 __fput+0x275/0x7a0 fs/file_table.c:210
 ____fput+0x16/0x20 fs/file_table.c:244
 task_work_run+0x114/0x190 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x1da/0x220 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4bc/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

The buggy address belongs to the object at ffff888089d480c0
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 104 bytes inside of
 256-byte region [ffff888089d480c0, ffff888089d481c0)
The buggy address belongs to the page:
page:ffffea0002275200 count:1 mapcount:0 mapping:ffff888089d480c0 index:0x0
flags: 0x1fffc0000000100(slab)
raw: 01fffc0000000100 ffff888089d480c0 0000000000000000 000000010000000c
raw: ffffea000228d2a0 ffffea0002a11820 ffff8880aa8007c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888089d48000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888089d48080: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
>ffff888089d48100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff888089d48180: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888089d48200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (1):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	Maintainers
ci2-linux-4-14	2019/07/01 16:23	linux-4.14.y	f4cc0ed9	907bf746	.config	log	report	syz		alexander.levin@microsoft.com, dledford@redhat.com, gregkh@linuxfoundation.org, gustavo@embeddedor.com, hal.rosenstock@gmail.com, jannh@google.com, jgg@mellanox.com, linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, sean.hefty@intel.com, xiyou.wangcong@gmail.com