linux.git/drivers/infiniband, branch v5.0.4 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git IB/rdmavt: Fix concurrency panics in QP post_send and modify to error 2019-03-23T19:11:28+00:00 Michael J. Ruhl michael.j.ruhl@intel.com 2019-02-26T16:45:25+00:00 25636de95557a95d54ac30be94af3748345a0a90 commit d757c60eca9b22f4d108929a24401e0fdecda0b1 upstream. The RC/UC code path can go through a software loopback. In this code path the receive side QP is manipulated. If two threads are working on the QP receive side (i.e. post_send, and modify_qp to an error state), QP information can be corrupted. (post_send via loopback) set r_sge loop update r_sge (modify_qp) take r_lock update r_sge <---- r_sge is now incorrect (post_send) update r_sge <---- crash, etc. ... This can lead to one of the two following crashes: BUG: unable to handle kernel NULL pointer dereference at (null) IP: hfi1_copy_sge+0xf1/0x2e0 [hfi1] PGD 8000001fe6a57067 PUD 1fd9e0c067 PMD 0 Call Trace: ruc_loopback+0x49b/0xbc0 [hfi1] hfi1_do_send+0x38e/0x3e0 [hfi1] _hfi1_do_send+0x1e/0x20 [hfi1] process_one_work+0x17f/0x440 worker_thread+0x126/0x3c0 kthread+0xd1/0xe0 ret_from_fork_nospec_begin+0x21/0x21 or: BUG: unable to handle kernel NULL pointer dereference at 0000000000000048 IP: rvt_clear_mr_refs+0x45/0x370 [rdmavt] PGD 80000006ae5eb067 PUD ef15d0067 PMD 0 Call Trace: rvt_error_qp+0xaa/0x240 [rdmavt] rvt_modify_qp+0x47f/0xaa0 [rdmavt] ib_security_modify_qp+0x8f/0x400 [ib_core] ib_modify_qp_with_udata+0x44/0x70 [ib_core] modify_qp.isra.23+0x1eb/0x2b0 [ib_uverbs] ib_uverbs_modify_qp+0xaa/0xf0 [ib_uverbs] ib_uverbs_write+0x272/0x430 [ib_uverbs] vfs_write+0xc0/0x1f0 SyS_write+0x7f/0xf0 system_call_fastpath+0x1c/0x21 Fix by using the appropriate locking on the receiving QP. Fixes: 15703461533a ("IB/{hfi1, qib, rdmavt}: Move ruc_loopback to rdmavt") Cc: <stable@vger.kernel.org> #v4.9+ Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com> Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com> Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d757c60eca9b22f4d108929a24401e0fdecda0b1 upstream.

The RC/UC code path can go through a software loopback. In this code path
the receive side QP is manipulated.

If two threads are working on the QP receive side (i.e. post_send, and
modify_qp to an error state), QP information can be corrupted.

(post_send via loopback)
  set r_sge
  loop
     update r_sge
(modify_qp)
     take r_lock
     update r_sge <---- r_sge is now incorrect
(post_send)
     update r_sge <---- crash, etc.
     ...

This can lead to one of the two following crashes:

 BUG: unable to handle kernel NULL pointer dereference at (null)
  IP:  hfi1_copy_sge+0xf1/0x2e0 [hfi1]
  PGD 8000001fe6a57067 PUD 1fd9e0c067 PMD 0
 Call Trace:
  ruc_loopback+0x49b/0xbc0 [hfi1]
  hfi1_do_send+0x38e/0x3e0 [hfi1]
  _hfi1_do_send+0x1e/0x20 [hfi1]
  process_one_work+0x17f/0x440
  worker_thread+0x126/0x3c0
  kthread+0xd1/0xe0
  ret_from_fork_nospec_begin+0x21/0x21

or:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000048
  IP:  rvt_clear_mr_refs+0x45/0x370 [rdmavt]
  PGD 80000006ae5eb067 PUD ef15d0067 PMD 0
 Call Trace:
  rvt_error_qp+0xaa/0x240 [rdmavt]
  rvt_modify_qp+0x47f/0xaa0 [rdmavt]
  ib_security_modify_qp+0x8f/0x400 [ib_core]
  ib_modify_qp_with_udata+0x44/0x70 [ib_core]
  modify_qp.isra.23+0x1eb/0x2b0 [ib_uverbs]
  ib_uverbs_modify_qp+0xaa/0xf0 [ib_uverbs]
  ib_uverbs_write+0x272/0x430 [ib_uverbs]
  vfs_write+0xc0/0x1f0
  SyS_write+0x7f/0xf0
  system_call_fastpath+0x1c/0x21

Fix by using the appropriate locking on the receiving QP.

Fixes: 15703461533a ("IB/{hfi1, qib, rdmavt}: Move ruc_loopback to rdmavt")
Cc: <stable@vger.kernel.org> #v4.9+
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
IB/rdmavt: Fix loopback send with invalidate ordering 2019-03-23T19:11:28+00:00 Mike Marciniszyn mike.marciniszyn@intel.com 2019-02-26T16:45:16+00:00 ada60723d7cd01d811d20144db50da96e633e8c2 commit 38bbc9f0381550d1d227fc57afa08436e36b32fc upstream. The IBTA spec notes: o9-5.2.1: For any HCA which supports SEND with Invalidate, upon receiving an IETH, the Invalidate operation must not take place until after the normal transport header validation checks have been successfully completed. The rdmavt loopback code does the validation after the invalidate. Fix by relocating the operation specific logic for all SEND variants until after the validity checks. Cc: <stable@vger.kernel.org> #v4.20+ Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com> Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com> Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 38bbc9f0381550d1d227fc57afa08436e36b32fc upstream.

The IBTA spec notes:

o9-5.2.1: For any HCA which supports SEND with Invalidate, upon receiving
an IETH, the Invalidate operation must not take place until after the
normal transport header validation checks have been successfully
completed.

The rdmavt loopback code does the validation after the invalidate.

Fix by relocating the operation specific logic for all SEND variants until
after the validity checks.

Cc: <stable@vger.kernel.org> #v4.20+
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
IB/hfi1: Close race condition on user context disable and close 2019-03-23T19:11:28+00:00 Michael J. Ruhl michael.j.ruhl@intel.com 2019-02-26T16:45:35+00:00 c8a23dfeb2d63e79a1cb60640007c04e6c4c39fb commit bc5add09764c123f58942a37c8335247e683d234 upstream. When disabling and removing a receive context, it is possible for an asynchronous event (i.e IRQ) to occur. Because of this, there is a race between cleaning up the context, and the context being used by the asynchronous event. cpu 0 (context cleanup) rc->ref_count-- (ref_count == 0) hfi1_rcd_free() cpu 1 (IRQ (with rcd index)) rcd_get_by_index() lock ref_count+++ <-- reference count race (WARNING) return rcd unlock cpu 0 hfi1_free_ctxtdata() <-- incorrect free location lock remove rcd from array unlock free rcd This race will cause the following WARNING trace: WARNING: CPU: 0 PID: 175027 at include/linux/kref.h:52 hfi1_rcd_get_by_index+0x84/0xa0 [hfi1] CPU: 0 PID: 175027 Comm: IMB-MPI1 Kdump: loaded Tainted: G OE ------------ 3.10.0-957.el7.x86_64 #1 Hardware name: Intel Corporation S2600KP/S2600KP, BIOS SE5C610.86B.11.01.0076.C4.111920150602 11/19/2015 Call Trace: dump_stack+0x19/0x1b __warn+0xd8/0x100 warn_slowpath_null+0x1d/0x20 hfi1_rcd_get_by_index+0x84/0xa0 [hfi1] is_rcv_urgent_int+0x24/0x90 [hfi1] general_interrupt+0x1b6/0x210 [hfi1] __handle_irq_event_percpu+0x44/0x1c0 handle_irq_event_percpu+0x32/0x80 handle_irq_event+0x3c/0x60 handle_edge_irq+0x7f/0x150 handle_irq+0xe4/0x1a0 do_IRQ+0x4d/0xf0 common_interrupt+0x162/0x162 The race can also lead to a use after free which could be similar to: general protection fault: 0000 1 SMP CPU: 71 PID: 177147 Comm: IMB-MPI1 Kdump: loaded Tainted: G W OE ------------ 3.10.0-957.el7.x86_64 #1 Hardware name: Intel Corporation S2600KP/S2600KP, BIOS SE5C610.86B.11.01.0076.C4.111920150602 11/19/2015 task: ffff9962a8098000 ti: ffff99717a508000 task.ti: ffff99717a508000 __kmalloc+0x94/0x230 Call Trace: ? hfi1_user_sdma_process_request+0x9c8/0x1250 [hfi1] hfi1_user_sdma_process_request+0x9c8/0x1250 [hfi1] hfi1_aio_write+0xba/0x110 [hfi1] do_sync_readv_writev+0x7b/0xd0 do_readv_writev+0xce/0x260 ? handle_mm_fault+0x39d/0x9b0 ? pick_next_task_fair+0x5f/0x1b0 ? sched_clock_cpu+0x85/0xc0 ? __schedule+0x13a/0x890 vfs_writev+0x35/0x60 SyS_writev+0x7f/0x110 system_call_fastpath+0x22/0x27 Use the appropriate kref API to verify access. Reorder context cleanup to ensure context removal before cleanup occurs correctly. Cc: stable@vger.kernel.org # v4.14.0+ Fixes: f683c80ca68e ("IB/hfi1: Resolve kernel panics by reference counting receive contexts") Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com> Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com> Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit bc5add09764c123f58942a37c8335247e683d234 upstream.

When disabling and removing a receive context, it is possible for an
asynchronous event (i.e IRQ) to occur.  Because of this, there is a race
between cleaning up the context, and the context being used by the
asynchronous event.

cpu 0  (context cleanup)
    rc->ref_count-- (ref_count == 0)
    hfi1_rcd_free()
cpu 1  (IRQ (with rcd index))
	rcd_get_by_index()
	lock
	ref_count+++     <-- reference count race (WARNING)
	return rcd
	unlock
cpu 0
    hfi1_free_ctxtdata() <-- incorrect free location
    lock
    remove rcd from array
    unlock
    free rcd

This race will cause the following WARNING trace:

WARNING: CPU: 0 PID: 175027 at include/linux/kref.h:52 hfi1_rcd_get_by_index+0x84/0xa0 [hfi1]
CPU: 0 PID: 175027 Comm: IMB-MPI1 Kdump: loaded Tainted: G OE ------------ 3.10.0-957.el7.x86_64 #1
Hardware name: Intel Corporation S2600KP/S2600KP, BIOS SE5C610.86B.11.01.0076.C4.111920150602 11/19/2015
Call Trace:
  dump_stack+0x19/0x1b
  __warn+0xd8/0x100
  warn_slowpath_null+0x1d/0x20
  hfi1_rcd_get_by_index+0x84/0xa0 [hfi1]
  is_rcv_urgent_int+0x24/0x90 [hfi1]
  general_interrupt+0x1b6/0x210 [hfi1]
  __handle_irq_event_percpu+0x44/0x1c0
  handle_irq_event_percpu+0x32/0x80
  handle_irq_event+0x3c/0x60
  handle_edge_irq+0x7f/0x150
  handle_irq+0xe4/0x1a0
  do_IRQ+0x4d/0xf0
  common_interrupt+0x162/0x162

The race can also lead to a use after free which could be similar to:

general protection fault: 0000 1 SMP
CPU: 71 PID: 177147 Comm: IMB-MPI1 Kdump: loaded Tainted: G W OE ------------ 3.10.0-957.el7.x86_64 #1
Hardware name: Intel Corporation S2600KP/S2600KP, BIOS SE5C610.86B.11.01.0076.C4.111920150602 11/19/2015
task: ffff9962a8098000 ti: ffff99717a508000 task.ti: ffff99717a508000 __kmalloc+0x94/0x230
Call Trace:
  ? hfi1_user_sdma_process_request+0x9c8/0x1250 [hfi1]
  hfi1_user_sdma_process_request+0x9c8/0x1250 [hfi1]
  hfi1_aio_write+0xba/0x110 [hfi1]
  do_sync_readv_writev+0x7b/0xd0
  do_readv_writev+0xce/0x260
  ? handle_mm_fault+0x39d/0x9b0
  ? pick_next_task_fair+0x5f/0x1b0
  ? sched_clock_cpu+0x85/0xc0
  ? __schedule+0x13a/0x890
  vfs_writev+0x35/0x60
  SyS_writev+0x7f/0x110
  system_call_fastpath+0x22/0x27

Use the appropriate kref API to verify access.

Reorder context cleanup to ensure context removal before cleanup occurs
correctly.

Cc: stable@vger.kernel.org # v4.14.0+
Fixes: f683c80ca68e ("IB/hfi1: Resolve kernel panics by reference counting receive contexts")
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
iw_cxgb4: cq/qp mask depends on bar2 pages in a host page 2019-02-15T16:39:39+00:00 Raju Rangoju rajur@chelsio.com 2019-02-14T12:10:54+00:00 f09ef134a7ca3f0d2ce485a757f5b79809ebb803 Adjust the cq/qp mask based on the number of bar2 pages in a host page. For user-mode rdma, the granularity of the BAR2 memory mapped to a user rdma process during queue allocation must be based on the host page size. The lld attributes udb_density and ucq_density are used to figure out how many sge contexts are in a bar2 page. So the rdev->qpmask and rdev->cqmask in iw_cxgb4 need to now be adjusted based on how many sge bar2 pages are in a host page. Otherwise the device fails to work on non 4k page size systems. Fixes: 2391b0030e24 ("cxgb4: Remove SGE_HOST_PAGE_SIZE dependency on page size") Signed-off-by: Raju Rangoju <rajur@chelsio.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> 
Adjust the cq/qp mask based on the number of bar2 pages in a host page.

For user-mode rdma, the granularity of the BAR2 memory mapped to a user
rdma process during queue allocation must be based on the host page
size. The lld attributes udb_density and ucq_density are used to figure
out how many sge contexts are in a bar2 page. So the rdev->qpmask and
rdev->cqmask in iw_cxgb4 need to now be adjusted based on how many sge
bar2 pages are in a host page.

Otherwise the device fails to work on non 4k page size systems.

Fixes: 2391b0030e24 ("cxgb4: Remove SGE_HOST_PAGE_SIZE dependency on page size")
Signed-off-by: Raju Rangoju <rajur@chelsio.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
RDMA/srp: Rework SCSI device reset handling 2019-02-04T23:31:33+00:00 Bart Van Assche bvanassche@acm.org 2019-01-30T22:05:55+00:00 48396e80fb6526ea5ed267bd84f028bae56d2f9e Since .scsi_done() must only be called after scsi_queue_rq() has finished, make sure that the SRP initiator driver does not call .scsi_done() while scsi_queue_rq() is in progress. Although invoking sg_reset -d while I/O is in progress works fine with kernel v4.20 and before, that is not the case with kernel v5.0-rc1. This patch avoids that the following crash is triggered with kernel v5.0-rc1: BUG: unable to handle kernel NULL pointer dereference at 0000000000000138 CPU: 0 PID: 360 Comm: kworker/0:1H Tainted: G B 5.0.0-rc1-dbg+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 Workqueue: kblockd blk_mq_run_work_fn RIP: 0010:blk_mq_dispatch_rq_list+0x116/0xb10 Call Trace: blk_mq_sched_dispatch_requests+0x2f7/0x300 __blk_mq_run_hw_queue+0xd6/0x180 blk_mq_run_work_fn+0x27/0x30 process_one_work+0x4f1/0xa20 worker_thread+0x67/0x5b0 kthread+0x1cf/0x1f0 ret_from_fork+0x24/0x30 Cc: <stable@vger.kernel.org> Fixes: 94a9174c630c ("IB/srp: reduce lock coverage of command completion") Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> 
Since .scsi_done() must only be called after scsi_queue_rq() has
finished, make sure that the SRP initiator driver does not call
.scsi_done() while scsi_queue_rq() is in progress. Although
invoking sg_reset -d while I/O is in progress works fine with kernel
v4.20 and before, that is not the case with kernel v5.0-rc1. This
patch avoids that the following crash is triggered with kernel
v5.0-rc1:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000138
CPU: 0 PID: 360 Comm: kworker/0:1H Tainted: G    B             5.0.0-rc1-dbg+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
Workqueue: kblockd blk_mq_run_work_fn
RIP: 0010:blk_mq_dispatch_rq_list+0x116/0xb10
Call Trace:
 blk_mq_sched_dispatch_requests+0x2f7/0x300
 __blk_mq_run_hw_queue+0xd6/0x180
 blk_mq_run_work_fn+0x27/0x30
 process_one_work+0x4f1/0xa20
 worker_thread+0x67/0x5b0
 kthread+0x1cf/0x1f0
 ret_from_fork+0x24/0x30

Cc: <stable@vger.kernel.org>
Fixes: 94a9174c630c ("IB/srp: reduce lock coverage of command completion")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
IB/uverbs: Fix OOPs in uverbs_user_mmap_disassociate 2019-01-29T20:57:22+00:00 Yishai Hadas yishaih@mellanox.com 2019-01-27T08:11:27+00:00 7b21b69ab203136fdc153c7707fa6c409e523c2e The vma->vm_mm can become impossible to get before rdma_umap_close() is called, in this case we must not try to get an mm that is already undergoing process exit. In this case there is no need to wait for anything as the VMA will be destroyed by another thread soon and is already effectively 'unreachable' by userspace. BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 PGD 800000012bc50067 P4D 800000012bc50067 PUD 129db5067 PMD 0 Oops: 0000 [#1] SMP PTI CPU: 1 PID: 2050 Comm: bash Tainted: G W OE 4.20.0-rc6+ #3 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 RIP: 0010:__rb_erase_color+0xb9/0x280 Code: 84 17 01 00 00 48 3b 68 10 0f 84 15 01 00 00 48 89 58 08 48 89 de 48 89 ef 4c 89 e3 e8 90 84 22 00 e9 60 ff ff ff 48 8b 5d 10 <f6> 03 01 0f 84 9c 00 00 00 48 8b 43 10 48 85 c0 74 09 f6 00 01 0f RSP: 0018:ffffbecfc090bab8 EFLAGS: 00010246 RAX: ffff97616346cf30 RBX: 0000000000000000 RCX: 0000000000000101 RDX: 0000000000000000 RSI: ffff97623b6ca828 RDI: ffff97621ef10828 RBP: ffff97621ef10828 R08: ffff97621ef10828 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff97623b6ca838 R13: ffffffffbb3fef50 R14: ffff97623b6ca828 R15: 0000000000000000 FS: 00007f7a5c31d740(0000) GS:ffff97623bb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000011255a000 CR4: 00000000000006e0 Call Trace: unlink_file_vma+0x3b/0x50 free_pgtables+0xa1/0x110 exit_mmap+0xca/0x1a0 ? mlx5_ib_dealloc_pd+0x28/0x30 [mlx5_ib] mmput+0x54/0x140 uverbs_user_mmap_disassociate+0xcc/0x160 [ib_uverbs] uverbs_destroy_ufile_hw+0xf7/0x120 [ib_uverbs] ib_uverbs_remove_one+0xea/0x240 [ib_uverbs] ib_unregister_device+0xfb/0x200 [ib_core] mlx5_ib_remove+0x51/0xe0 [mlx5_ib] mlx5_remove_device+0xc1/0xd0 [mlx5_core] mlx5_unregister_device+0x3d/0xb0 [mlx5_core] remove_one+0x2a/0x90 [mlx5_core] pci_device_remove+0x3b/0xc0 device_release_driver_internal+0x16d/0x240 unbind_store+0xb2/0x100 kernfs_fop_write+0x102/0x180 __vfs_write+0x36/0x1a0 ? __alloc_fd+0xa9/0x170 ? set_close_on_exec+0x49/0x70 vfs_write+0xad/0x1a0 ksys_write+0x52/0xc0 do_syscall_64+0x5b/0x180 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Cc: <stable@vger.kernel.org> # 4.19 Fixes: 5f9794dc94f5 ("RDMA/ucontext: Add a core API for mmaping driver IO memory") Signed-off-by: Yishai Hadas <yishaih@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> 
The vma->vm_mm can become impossible to get before rdma_umap_close() is
called, in this case we must not try to get an mm that is already
undergoing process exit. In this case there is no need to wait for
anything as the VMA will be destroyed by another thread soon and is
already effectively 'unreachable' by userspace.

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
 PGD 800000012bc50067 P4D 800000012bc50067 PUD 129db5067 PMD 0
 Oops: 0000 [#1] SMP PTI
 CPU: 1 PID: 2050 Comm: bash Tainted: G        W  OE 4.20.0-rc6+ #3
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 RIP: 0010:__rb_erase_color+0xb9/0x280
 Code: 84 17 01 00 00 48 3b 68 10 0f 84 15 01 00 00 48 89
               58 08 48 89 de 48 89 ef 4c 89 e3 e8 90 84 22 00 e9 60 ff ff ff 48 8b 5d
               10 <f6> 03 01 0f 84 9c 00 00 00 48 8b 43 10 48 85 c0 74 09 f6 00 01 0f
 RSP: 0018:ffffbecfc090bab8 EFLAGS: 00010246
 RAX: ffff97616346cf30 RBX: 0000000000000000 RCX: 0000000000000101
 RDX: 0000000000000000 RSI: ffff97623b6ca828 RDI: ffff97621ef10828
 RBP: ffff97621ef10828 R08: ffff97621ef10828 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000000 R12: ffff97623b6ca838
 R13: ffffffffbb3fef50 R14: ffff97623b6ca828 R15: 0000000000000000
 FS:  00007f7a5c31d740(0000) GS:ffff97623bb00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 000000011255a000 CR4: 00000000000006e0
 Call Trace:
  unlink_file_vma+0x3b/0x50
  free_pgtables+0xa1/0x110
  exit_mmap+0xca/0x1a0
  ? mlx5_ib_dealloc_pd+0x28/0x30 [mlx5_ib]
  mmput+0x54/0x140
  uverbs_user_mmap_disassociate+0xcc/0x160 [ib_uverbs]
  uverbs_destroy_ufile_hw+0xf7/0x120 [ib_uverbs]
  ib_uverbs_remove_one+0xea/0x240 [ib_uverbs]
  ib_unregister_device+0xfb/0x200 [ib_core]
  mlx5_ib_remove+0x51/0xe0 [mlx5_ib]
  mlx5_remove_device+0xc1/0xd0 [mlx5_core]
  mlx5_unregister_device+0x3d/0xb0 [mlx5_core]
  remove_one+0x2a/0x90 [mlx5_core]
  pci_device_remove+0x3b/0xc0
  device_release_driver_internal+0x16d/0x240
  unbind_store+0xb2/0x100
  kernfs_fop_write+0x102/0x180
  __vfs_write+0x36/0x1a0
  ? __alloc_fd+0xa9/0x170
  ? set_close_on_exec+0x49/0x70
  vfs_write+0xad/0x1a0
  ksys_write+0x52/0xc0
  do_syscall_64+0x5b/0x180
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Cc: <stable@vger.kernel.org> # 4.19
Fixes: 5f9794dc94f5 ("RDMA/ucontext: Add a core API for mmaping driver IO memory")
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
IB/ipoib: Fix for use-after-free in ipoib_cm_tx_start 2019-01-25T19:17:54+00:00 Feras Daoud ferasda@mellanox.com 2019-01-24T12:33:19+00:00 6ab4aba00f811a5265acc4d3eb1863bb3ca60562 The following BUG was reported by kasan: BUG: KASAN: use-after-free in ipoib_cm_tx_start+0x430/0x1390 [ib_ipoib] Read of size 80 at addr ffff88034c30bcd0 by task kworker/u16:1/24020 Workqueue: ipoib_wq ipoib_cm_tx_start [ib_ipoib] Call Trace: dump_stack+0x9a/0xeb print_address_description+0xe3/0x2e0 kasan_report+0x18a/0x2e0 ? ipoib_cm_tx_start+0x430/0x1390 [ib_ipoib] memcpy+0x1f/0x50 ipoib_cm_tx_start+0x430/0x1390 [ib_ipoib] ? kvm_clock_read+0x1f/0x30 ? ipoib_cm_skb_reap+0x610/0x610 [ib_ipoib] ? __lock_is_held+0xc2/0x170 ? process_one_work+0x880/0x1960 ? process_one_work+0x912/0x1960 process_one_work+0x912/0x1960 ? wq_pool_ids_show+0x310/0x310 ? lock_acquire+0x145/0x440 worker_thread+0x87/0xbb0 ? process_one_work+0x1960/0x1960 kthread+0x314/0x3d0 ? kthread_create_worker_on_cpu+0xc0/0xc0 ret_from_fork+0x3a/0x50 Allocated by task 0: kasan_kmalloc+0xa0/0xd0 kmem_cache_alloc_trace+0x168/0x3e0 path_rec_create+0xa2/0x1f0 [ib_ipoib] ipoib_start_xmit+0xa98/0x19e0 [ib_ipoib] dev_hard_start_xmit+0x159/0x8d0 sch_direct_xmit+0x226/0xb40 __dev_queue_xmit+0x1d63/0x2950 neigh_update+0x889/0x1770 arp_process+0xc47/0x21f0 arp_rcv+0x462/0x760 __netif_receive_skb_core+0x1546/0x2da0 netif_receive_skb_internal+0xf2/0x590 napi_gro_receive+0x28e/0x390 ipoib_ib_handle_rx_wc_rss+0x873/0x1b60 [ib_ipoib] ipoib_rx_poll_rss+0x17d/0x320 [ib_ipoib] net_rx_action+0x427/0xe30 __do_softirq+0x28e/0xc42 Freed by task 26680: __kasan_slab_free+0x11d/0x160 kfree+0xf5/0x360 ipoib_flush_paths+0x532/0x9d0 [ib_ipoib] ipoib_set_mode_rss+0x1ad/0x560 [ib_ipoib] set_mode+0xc8/0x150 [ib_ipoib] kernfs_fop_write+0x279/0x440 __vfs_write+0xd8/0x5c0 vfs_write+0x15e/0x470 ksys_write+0xb8/0x180 do_syscall_64+0x9b/0x420 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88034c30bcc8 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 8 bytes inside of 512-byte region [ffff88034c30bcc8, ffff88034c30bec8) The buggy address belongs to the page: The following race between change mode and xmit flow is the reason for this use-after-free: Change mode Send packet 1 to GID XX Send packet 2 to GID XX | | | start | | | | | | | | | Create new path for GID XX | | and update neigh path | | | | | | | | | | flush_paths | | | | queue_work(cm.start_task) | | Path for GID XX not found | create new path | | start_task runs with old released path There is no locking to protect the lifetime of the path through the ipoib_cm_tx struct, so delete it entirely and always use the newly looked up path under the priv->lock. Fixes: 546481c2816e ("IB/ipoib: Fix memory corruption in ipoib cm mode connect flow") Signed-off-by: Feras Daoud <ferasda@mellanox.com> Reviewed-by: Erez Shitrit <erezsh@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> 
The following BUG was reported by kasan:

 BUG: KASAN: use-after-free in ipoib_cm_tx_start+0x430/0x1390 [ib_ipoib]
 Read of size 80 at addr ffff88034c30bcd0 by task kworker/u16:1/24020

 Workqueue: ipoib_wq ipoib_cm_tx_start [ib_ipoib]
 Call Trace:
  dump_stack+0x9a/0xeb
  print_address_description+0xe3/0x2e0
  kasan_report+0x18a/0x2e0
  ? ipoib_cm_tx_start+0x430/0x1390 [ib_ipoib]
  memcpy+0x1f/0x50
  ipoib_cm_tx_start+0x430/0x1390 [ib_ipoib]
  ? kvm_clock_read+0x1f/0x30
  ? ipoib_cm_skb_reap+0x610/0x610 [ib_ipoib]
  ? __lock_is_held+0xc2/0x170
  ? process_one_work+0x880/0x1960
  ? process_one_work+0x912/0x1960
  process_one_work+0x912/0x1960
  ? wq_pool_ids_show+0x310/0x310
  ? lock_acquire+0x145/0x440
  worker_thread+0x87/0xbb0
  ? process_one_work+0x1960/0x1960
  kthread+0x314/0x3d0
  ? kthread_create_worker_on_cpu+0xc0/0xc0
  ret_from_fork+0x3a/0x50

 Allocated by task 0:
  kasan_kmalloc+0xa0/0xd0
  kmem_cache_alloc_trace+0x168/0x3e0
  path_rec_create+0xa2/0x1f0 [ib_ipoib]
  ipoib_start_xmit+0xa98/0x19e0 [ib_ipoib]
  dev_hard_start_xmit+0x159/0x8d0
  sch_direct_xmit+0x226/0xb40
  __dev_queue_xmit+0x1d63/0x2950
  neigh_update+0x889/0x1770
  arp_process+0xc47/0x21f0
  arp_rcv+0x462/0x760
  __netif_receive_skb_core+0x1546/0x2da0
  netif_receive_skb_internal+0xf2/0x590
  napi_gro_receive+0x28e/0x390
  ipoib_ib_handle_rx_wc_rss+0x873/0x1b60 [ib_ipoib]
  ipoib_rx_poll_rss+0x17d/0x320 [ib_ipoib]
  net_rx_action+0x427/0xe30
  __do_softirq+0x28e/0xc42

 Freed by task 26680:
  __kasan_slab_free+0x11d/0x160
  kfree+0xf5/0x360
  ipoib_flush_paths+0x532/0x9d0 [ib_ipoib]
  ipoib_set_mode_rss+0x1ad/0x560 [ib_ipoib]
  set_mode+0xc8/0x150 [ib_ipoib]
  kernfs_fop_write+0x279/0x440
  __vfs_write+0xd8/0x5c0
  vfs_write+0x15e/0x470
  ksys_write+0xb8/0x180
  do_syscall_64+0x9b/0x420
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

 The buggy address belongs to the object at ffff88034c30bcc8
                which belongs to the cache kmalloc-512 of size 512
 The buggy address is located 8 bytes inside of
                512-byte region [ffff88034c30bcc8, ffff88034c30bec8)
 The buggy address belongs to the page:

The following race between change mode and xmit flow is the reason for
this use-after-free:

Change mode     Send packet 1 to GID XX      Send packet 2 to GID XX
     |                    |                             |
   start                  |                             |
     |                    |                             |
     |                    |                             |
     |         Create new path for GID XX               |
     |           and update neigh path                  |
     |                    |                             |
     |                    |                             |
     |                    |                             |
 flush_paths              |                             |
                          |                             |
               queue_work(cm.start_task)                |
                          |                 Path for GID XX not found
                          |                      create new path
                          |
                          |
               start_task runs with old
                    released path

There is no locking to protect the lifetime of the path through the
ipoib_cm_tx struct, so delete it entirely and always use the newly looked
up path under the priv->lock.

Fixes: 546481c2816e ("IB/ipoib: Fix memory corruption in ipoib cm mode connect flow")
Signed-off-by: Feras Daoud <ferasda@mellanox.com>
Reviewed-by: Erez Shitrit <erezsh@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
IB/uverbs: Fix ioctl query port to consider device disassociation 2019-01-25T18:58:06+00:00 Yishai Hadas yishaih@mellanox.com 2019-01-24T13:00:07+00:00 f8ade8e2429758efa1eddf0a6e2cc936714afc8d Methods cannot peak into the ufile, the only way to get a ucontext and hence a device is via the ib_uverbs_get_ucontext() call or inspecing a locked uobject. Otherwise during/after disassociation the pointers may be null or free'd. BUG: unable to handle kernel NULL pointer dereference at 0000000000000078 PGD 800000005ece6067 P4D 800000005ece6067 PUD 5ece7067 PMD 0 Oops: 0000 [#1] SMP PTI CPU: 0 PID: 10631 Comm: ibv_ud_pingpong Tainted: GW OE 4.20.0-rc6+ #3 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 RIP: 0010:ib_uverbs_handler_UVERBS_METHOD_QUERY_PORT+0x53/0x191 [ib_uverbs] Code: 80 00 00 00 31 c0 48 8b 47 40 48 8d 5c 24 38 48 8d 6c 24 08 48 89 df 48 8b 40 08 4c 8b a0 18 03 00 00 31 c0 f3 48 ab 48 89 ef <49> 83 7c 24 78 00 b1 06 f3 48 ab 0f 84 89 00 00 00 45 31 c9 31 d2 RSP: 0018:ffffb54802ccfb10 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffb54802ccfb48 RCX:0000000000000000 RDX: fffffffffffffffa RSI: ffffb54802ccfcf8 RDI:ffffb54802ccfb18 RBP: ffffb54802ccfb18 R08: ffffb54802ccfd18 R09:0000000000000000 R10: 0000000000000000 R11: 00000000000000d0 R12:0000000000000000 R13: ffffb54802ccfcb0 R14: ffffb54802ccfc48 R15:ffff9f736e0059a0 FS: 00007f55a6bd7740(0000) GS:ffff9f737ba00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000078 CR3: 0000000064214000 CR4:00000000000006f0 Call Trace: ib_uverbs_cmd_verbs.isra.5+0x94d/0xa60 [ib_uverbs] ? copy_port_attr_to_resp+0x120/0x120 [ib_uverbs] ? arch_tlb_finish_mmu+0x16/0xc0 ? tlb_finish_mmu+0x1f/0x30 ? unmap_region+0xd9/0x120 ib_uverbs_ioctl+0xbc/0x120 [ib_uverbs] do_vfs_ioctl+0xa9/0x620 ? __do_munmap+0x29f/0x3a0 ksys_ioctl+0x60/0x90 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x5b/0x180 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f55a62cb567 Fixes: 641d1207d2ed ("IB/core: Move query port to ioctl") Signed-off-by: Yishai Hadas <yishaih@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> 
Methods cannot peak into the ufile, the only way to get a ucontext and
hence a device is via the ib_uverbs_get_ucontext() call or inspecing a
locked uobject.

Otherwise during/after disassociation the pointers may be null or free'd.

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000078
 PGD 800000005ece6067 P4D 800000005ece6067 PUD 5ece7067 PMD 0
 Oops: 0000 [#1] SMP PTI
 CPU: 0 PID: 10631 Comm: ibv_ud_pingpong Tainted: GW  OE     4.20.0-rc6+ #3
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 RIP: 0010:ib_uverbs_handler_UVERBS_METHOD_QUERY_PORT+0x53/0x191 [ib_uverbs]
 Code: 80 00 00 00 31 c0 48 8b 47 40 48 8d 5c 24 38 48 8d 6c 24
               08 48 89 df 48 8b 40 08 4c 8b a0 18 03 00 00 31 c0 f3 48 ab 48 89
               ef <49> 83 7c 24 78 00 b1 06 f3 48 ab 0f 84 89 00 00 00 45 31  c9 31 d2
 RSP: 0018:ffffb54802ccfb10 EFLAGS: 00010246
 RAX: 0000000000000000 RBX: ffffb54802ccfb48 RCX:0000000000000000
 RDX: fffffffffffffffa RSI: ffffb54802ccfcf8 RDI:ffffb54802ccfb18
 RBP: ffffb54802ccfb18 R08: ffffb54802ccfd18 R09:0000000000000000
 R10: 0000000000000000 R11: 00000000000000d0 R12:0000000000000000
 R13: ffffb54802ccfcb0 R14: ffffb54802ccfc48 R15:ffff9f736e0059a0
 FS:  00007f55a6bd7740(0000) GS:ffff9f737ba00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000078 CR3: 0000000064214000 CR4:00000000000006f0
 Call Trace:
  ib_uverbs_cmd_verbs.isra.5+0x94d/0xa60 [ib_uverbs]
  ? copy_port_attr_to_resp+0x120/0x120 [ib_uverbs]
  ? arch_tlb_finish_mmu+0x16/0xc0
  ? tlb_finish_mmu+0x1f/0x30
  ? unmap_region+0xd9/0x120
  ib_uverbs_ioctl+0xbc/0x120 [ib_uverbs]
  do_vfs_ioctl+0xa9/0x620
  ? __do_munmap+0x29f/0x3a0
  ksys_ioctl+0x60/0x90
  __x64_sys_ioctl+0x16/0x20
  do_syscall_64+0x5b/0x180
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7f55a62cb567

Fixes: 641d1207d2ed ("IB/core: Move query port to ioctl")
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
RDMA/mlx5: Fix flow creation on representors 2019-01-25T18:58:06+00:00 Mark Bloch markb@mellanox.com 2019-01-24T12:33:32+00:00 c1b03c25f5c1503e2db3ac1c0e12ef3e054fa065 The intention of the flow_is_supported was to disable the entire tree and methods that allow raw flow creation, but the grammar syntax has this disable the entire UVERBS_FLOW object. Since the method requires a MLX5_IB_OBJECT_FLOW_MATCHER there is no need to do anything, as it is automatically disabled when matchers are disabled. This restores the ability to create flow steering rules on representors via regular verbs. Fixes: a1462351b590 ("RDMA/mlx5: Fail early if user tries to create flows on IB representors") Signed-off-by: Mark Bloch <markb@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> 
The intention of the flow_is_supported was to disable the entire tree and
methods that allow raw flow creation, but the grammar syntax has this
disable the entire UVERBS_FLOW object. Since the method requires a
MLX5_IB_OBJECT_FLOW_MATCHER there is no need to do anything, as it is
automatically disabled when matchers are disabled.

This restores the ability to create flow steering rules on representors
via regular verbs.

Fixes: a1462351b590 ("RDMA/mlx5: Fail early if user tries to create flows on IB representors")
Signed-off-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
IB/uverbs: Fix OOPs upon device disassociation 2019-01-25T18:58:06+00:00 Yishai Hadas yishaih@mellanox.com 2019-01-24T12:33:12+00:00 425784aa5b029eeb80498c73a68f62c3ad1d3b3f The async_file might be freed before the disassociation has been ended, causing qp shutdown to use after free on it. Since uverbs_destroy_ufile_hw is not a fence, it returns if a disassociation is ongoing in another thread. It has to be written this way to avoid deadlock. However this means that the ufile FD close cannot destroy anything that may still be used by an active kref, such as the the async_file. To fix that move the kref_put() to be in ib_uverbs_release_file(). BUG: unable to handle kernel paging request at ffffffffba682787 PGD bc80e067 P4D bc80e067 PUD bc80f063 PMD 1313df163 PTE 80000000bc682061 Oops: 0003 [#1] SMP PTI CPU: 1 PID: 32410 Comm: bash Tainted: G OE 4.20.0-rc6+ #3 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 RIP: 0010:__pv_queued_spin_lock_slowpath+0x1b3/0x2a0 Code: 98 83 e2 60 49 89 df 48 8b 04 c5 80 18 72 ba 48 8d ba 80 32 02 00 ba 00 80 00 00 4c 8d 65 14 41 bd 01 00 00 00 48 01 c7 85 d2 <48> 89 2f 48 89 fb 74 14 8b 45 08 85 c0 75 42 84 d2 74 6b f3 90 83 RSP: 0018:ffffc1bbc064fb58 EFLAGS: 00010006 RAX: ffffffffba65f4e7 RBX: ffff9f209c656c00 RCX: 0000000000000001 RDX: 0000000000008000 RSI: 0000000000000000 RDI: ffffffffba682787 RBP: ffff9f217bb23280 R08: 0000000000000001 R09: 0000000000000000 R10: ffff9f209d2c7800 R11: ffffffffffffffe8 R12: ffff9f217bb23294 R13: 0000000000000001 R14: 0000000000000000 R15: ffff9f209c656c00 FS: 00007fac55aad740(0000) GS:ffff9f217bb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffba682787 CR3: 000000012f8e0000 CR4: 00000000000006e0 Call Trace: _raw_spin_lock_irq+0x27/0x30 ib_uverbs_release_uevent+0x1e/0xa0 [ib_uverbs] uverbs_free_qp+0x7e/0x90 [ib_uverbs] destroy_hw_idr_uobject+0x1c/0x50 [ib_uverbs] uverbs_destroy_uobject+0x2e/0x180 [ib_uverbs] __uverbs_cleanup_ufile+0x73/0x90 [ib_uverbs] uverbs_destroy_ufile_hw+0x5d/0x120 [ib_uverbs] ib_uverbs_remove_one+0xea/0x240 [ib_uverbs] ib_unregister_device+0xfb/0x200 [ib_core] mlx5_ib_remove+0x51/0xe0 [mlx5_ib] mlx5_remove_device+0xc1/0xd0 [mlx5_core] mlx5_unregister_device+0x3d/0xb0 [mlx5_core] remove_one+0x2a/0x90 [mlx5_core] pci_device_remove+0x3b/0xc0 device_release_driver_internal+0x16d/0x240 unbind_store+0xb2/0x100 kernfs_fop_write+0x102/0x180 __vfs_write+0x36/0x1a0 ? __alloc_fd+0xa9/0x170 ? set_close_on_exec+0x49/0x70 vfs_write+0xad/0x1a0 ksys_write+0x52/0xc0 do_syscall_64+0x5b/0x180 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fac551aac60 Cc: <stable@vger.kernel.org> # 4.2 Fixes: 036b10635739 ("IB/uverbs: Enable device removal when there are active user space applications") Signed-off-by: Yishai Hadas <yishaih@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> 
The async_file might be freed before the disassociation has been ended,
causing qp shutdown to use after free on it.

Since uverbs_destroy_ufile_hw is not a fence, it returns if a
disassociation is ongoing in another thread. It has to be written this way
to avoid deadlock. However this means that the ufile FD close cannot
destroy anything that may still be used by an active kref, such as the the
async_file.

To fix that move the kref_put() to be in ib_uverbs_release_file().

 BUG: unable to handle kernel paging request at ffffffffba682787
 PGD bc80e067 P4D bc80e067 PUD bc80f063 PMD 1313df163 PTE 80000000bc682061
 Oops: 0003 [#1] SMP PTI
 CPU: 1 PID: 32410 Comm: bash Tainted: G           OE 4.20.0-rc6+ #3
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 RIP: 0010:__pv_queued_spin_lock_slowpath+0x1b3/0x2a0
 Code: 98 83 e2 60 49 89 df 48 8b 04 c5 80 18 72 ba 48 8d
		ba 80 32 02 00 ba 00 80 00 00 4c 8d 65 14 41 bd 01 00 00 00 48 01 c7 85
		d2 <48> 89 2f 48 89 fb 74 14 8b 45 08 85 c0 75 42 84 d2 74 6b f3 90 83
 RSP: 0018:ffffc1bbc064fb58 EFLAGS: 00010006
 RAX: ffffffffba65f4e7 RBX: ffff9f209c656c00 RCX: 0000000000000001
 RDX: 0000000000008000 RSI: 0000000000000000 RDI: ffffffffba682787
 RBP: ffff9f217bb23280 R08: 0000000000000001 R09: 0000000000000000
 R10: ffff9f209d2c7800 R11: ffffffffffffffe8 R12: ffff9f217bb23294
 R13: 0000000000000001 R14: 0000000000000000 R15: ffff9f209c656c00
 FS:  00007fac55aad740(0000) GS:ffff9f217bb00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: ffffffffba682787 CR3: 000000012f8e0000 CR4: 00000000000006e0
 Call Trace:
  _raw_spin_lock_irq+0x27/0x30
  ib_uverbs_release_uevent+0x1e/0xa0 [ib_uverbs]
  uverbs_free_qp+0x7e/0x90 [ib_uverbs]
  destroy_hw_idr_uobject+0x1c/0x50 [ib_uverbs]
  uverbs_destroy_uobject+0x2e/0x180 [ib_uverbs]
  __uverbs_cleanup_ufile+0x73/0x90 [ib_uverbs]
  uverbs_destroy_ufile_hw+0x5d/0x120 [ib_uverbs]
  ib_uverbs_remove_one+0xea/0x240 [ib_uverbs]
  ib_unregister_device+0xfb/0x200 [ib_core]
  mlx5_ib_remove+0x51/0xe0 [mlx5_ib]
  mlx5_remove_device+0xc1/0xd0 [mlx5_core]
  mlx5_unregister_device+0x3d/0xb0 [mlx5_core]
  remove_one+0x2a/0x90 [mlx5_core]
  pci_device_remove+0x3b/0xc0
  device_release_driver_internal+0x16d/0x240
  unbind_store+0xb2/0x100
  kernfs_fop_write+0x102/0x180
  __vfs_write+0x36/0x1a0
  ? __alloc_fd+0xa9/0x170
  ? set_close_on_exec+0x49/0x70
  vfs_write+0xad/0x1a0
  ksys_write+0x52/0xc0
  do_syscall_64+0x5b/0x180
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7fac551aac60

Cc: <stable@vger.kernel.org> # 4.2
Fixes: 036b10635739 ("IB/uverbs: Enable device removal when there are active user space applications")
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>