RDMA uverbs fixes for 4.16

Hi,

The following four patches fix failures found during our regression testing.

Thanks

Leon Romanovsky (4):
RDMA/restrack: Increment CQ restrack object before committing RDMA/uverbs: Fix bad unlock balance in ib_uverbs_close_xrcd RDMA/uverbs: Fix circular locking dependency RDMA/uverbs: Sanitize user entered port numbers prior to access it

 drivers/infiniband/core/uverbs_cmd.c | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

--
2.16.1

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From: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/[email protected]>

Once the uobj is committed it is immediately possible another thread could destroy it, which worst case, can result in a use-after-free of the restrack objects.

---
 drivers/infiniband/core/uverbs_cmd.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

index 256934d1f64f..4e55f8325049 100644
@@ -1030,14 +1030,14 @@ static struct ib_ucq_object *create_cq(struct ib_uverbs_file *file,
 	resp.response_length = offsetof(typeof(resp), response_length) +
 		sizeof(resp.response_length);
 
+	cq->res.type = RDMA_RESTRACK_CQ;
+	rdma_restrack_add(&cq->res);
+
 	ret = cb(file, obj, &resp, ucore, context);
 	if (ret)
 		goto err_cb;
 
 	uobj_alloc_commit(&obj->uobject);
-	cq->res.type = RDMA_RESTRACK_CQ;
-	rdma_restrack_add(&cq->res);
-
 	return obj;
 
 err_cb:

2.16.1

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From: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/[email protected]>

The attempt to call ib_uverbs_close_xrcd() without calling to ib_uverbs_open_xrcd() will produce the following warning.

The design of RDMA/core ensures that destroy operation is atomic and doesn't need to be protected with lock.

=====================================
WARNING: bad unlock balance detected!
4.15.0+ #87 Not tainted
-------------------------------------
syzkaller223405/269 is trying to release lock (&uverbs_dev->xrcd_tree_mutex) at:
[<00000000b8703372>] ib_uverbs_close_xrcd+0x195/0x1f0
but there are no more locks to release!

other info that might help us debug this:
1 lock held by syzkaller223405/269:
#0: (&uverbs_dev->disassociate_srcu){....}, at: [<000000005af3b960>] ib_uverbs_write+0x265/0xef0

stack backtrace:
CPU: 0 PID: 269 Comm: syzkaller223405 Not tainted 4.15.0+ #87
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014
Call Trace:
 dump_stack+0xde/0x164
 ? dma_virt_map_sg+0x22c/0x22c
 ? ib_uverbs_write+0x265/0xef0
 ? console_unlock+0x502/0xbd0
 ? ib_uverbs_close_xrcd+0x195/0x1f0
 print_unlock_imbalance_bug+0x131/0x160
 lock_release+0x59d/0x1100
 ? ib_uverbs_close_xrcd+0x195/0x1f0
 ? lock_acquire+0x440/0x440
 ? lock_acquire+0x440/0x440
 __mutex_unlock_slowpath+0x88/0x670
 ? wait_for_completion+0x4c0/0x4c0
 ? rdma_lookup_get_uobject+0x145/0x2f0
 ib_uverbs_close_xrcd+0x195/0x1f0
 ? ib_uverbs_open_xrcd+0xdd0/0xdd0
 ib_uverbs_write+0x7f9/0xef0
 ? cyc2ns_read_end+0x10/0x10
 ? ib_uverbs_open_xrcd+0xdd0/0xdd0
 ? uverbs_devnode+0x110/0x110
 ? cyc2ns_read_end+0x10/0x10
 ? cyc2ns_read_end+0x10/0x10
 ? sched_clock_cpu+0x18/0x200
 __vfs_write+0x10d/0x700
 ? uverbs_devnode+0x110/0x110
 ? kernel_read+0x170/0x170
 ? __fget+0x358/0x5d0
 ? security_file_permission+0x93/0x260
 vfs_write+0x1b0/0x550
 SyS_write+0xc7/0x1a0
 ? SyS_read+0x1a0/0x1a0
 ? trace_hardirqs_on_thunk+0x1a/0x1c
 entry_SYSCALL_64_fastpath+0x1e/0x8b
RIP: 0033:0x4335c9

---
 drivers/infiniband/core/uverbs_cmd.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

index 4e55f8325049..1187b757d911 100644
@@ -603,10 +603,8 @@ ssize_t ib_uverbs_close_xrcd(struct ib_uverbs_file *file,
 
 	uobj  = uobj_get_write(uobj_get_type(xrcd), cmd.xrcd_handle,
 			       file->ucontext);
-	if (IS_ERR(uobj)) {
-		mutex_unlock(&file->device->xrcd_tree_mutex);
+	if (IS_ERR(uobj))
 		return PTR_ERR(uobj);
-	}
 
 	ret = uobj_remove_commit(uobj);
 	return ret ?: in_len;

2.16.1

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From: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/[email protected]>

Avoid circular locking dependency by calling to uobj_alloc_commit() outside of xrcd_tree_mutex lock.

======================================================
WARNING: possible circular locking dependency detected
4.15.0+ #87 Not tainted
------------------------------------------------------
syzkaller401056/269 is trying to acquire lock:
(&uverbs_dev->xrcd_tree_mutex){+.+.}, at: [<000000006c12d2cd>] uverbs_free_xrcd+0xd2/0x360

but task is already holding lock:
(&ucontext->uobjects_lock){+.+.}, at: [<00000000da010f09>] uverbs_cleanup_ucontext+0x168/0x730

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&ucontext->uobjects_lock){+.+.}:

       __mutex_lock+0x111/0x1720
       rdma_alloc_commit_uobject+0x22c/0x600
       ib_uverbs_open_xrcd+0x61a/0xdd0
       ib_uverbs_write+0x7f9/0xef0
       __vfs_write+0x10d/0x700
       vfs_write+0x1b0/0x550
       SyS_write+0xc7/0x1a0
       entry_SYSCALL_64_fastpath+0x1e/0x8b

-> #0 (&uverbs_dev->xrcd_tree_mutex){+.+.}:

       lock_acquire+0x19d/0x440
       __mutex_lock+0x111/0x1720
       uverbs_free_xrcd+0xd2/0x360
       remove_commit_idr_uobject+0x6d/0x110
       uverbs_cleanup_ucontext+0x2f0/0x730
       ib_uverbs_cleanup_ucontext.constprop.3+0x52/0x120
       ib_uverbs_close+0xf2/0x570
       __fput+0x2cd/0x8d0
       task_work_run+0xec/0x1d0
       do_exit+0x6a1/0x1520
       do_group_exit+0xe8/0x380
       SyS_exit_group+0x1e/0x20
       entry_SYSCALL_64_fastpath+0x1e/0x8b

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ucontext->uobjects_lock);
                               lock(&uverbs_dev->xrcd_tree_mutex);
                               lock(&ucontext->uobjects_lock);

lock(&uverbs_dev->xrcd_tree_mutex);

*** DEADLOCK ***

3 locks held by syzkaller401056/269:

 #0:  (&file->cleanup_mutex){+.+.}, at: [<00000000c9f0c252>] ib_uverbs_close+0xac/0x570
 #1:  (&ucontext->cleanup_rwsem){++++}, at: [<00000000b6994d49>] uverbs_cleanup_ucontext+0xf6/0x730
 #2:  (&ucontext->uobjects_lock){+.+.}, at: [<00000000da010f09>] uverbs_cleanup_ucontext+0x168/0x730

stack backtrace:
CPU: 0 PID: 269 Comm: syzkaller401056 Not tainted 4.15.0+ #87
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014
Call Trace:
 dump_stack+0xde/0x164
 ? dma_virt_map_sg+0x22c/0x22c
 ? uverbs_cleanup_ucontext+0x168/0x730
 ? console_unlock+0x502/0xbd0
 print_circular_bug.isra.24+0x35e/0x396
 ? print_circular_bug_header+0x12e/0x12e
 ? find_usage_backwards+0x30/0x30
 ? entry_SYSCALL_64_fastpath+0x1e/0x8b
 validate_chain.isra.28+0x25d1/0x40c0
 ? check_usage+0xb70/0xb70
 ? graph_lock+0x160/0x160
 ? find_usage_backwards+0x30/0x30
 ? cyc2ns_read_end+0x10/0x10
 ? print_irqtrace_events+0x280/0x280
 ? __lock_acquire+0x93d/0x1630
 __lock_acquire+0x93d/0x1630
 lock_acquire+0x19d/0x440
 ? uverbs_free_xrcd+0xd2/0x360
 __mutex_lock+0x111/0x1720
 ? uverbs_free_xrcd+0xd2/0x360
 ? uverbs_free_xrcd+0xd2/0x360
 ? __mutex_lock+0x828/0x1720
 ? mutex_lock_io_nested+0x1550/0x1550
 ? uverbs_cleanup_ucontext+0x168/0x730
 ? __lock_acquire+0x9a9/0x1630
 ? mutex_lock_io_nested+0x1550/0x1550
 ? uverbs_cleanup_ucontext+0xf6/0x730
 ? lock_contended+0x11a0/0x11a0
 ? uverbs_free_xrcd+0xd2/0x360
 uverbs_free_xrcd+0xd2/0x360
 remove_commit_idr_uobject+0x6d/0x110
 uverbs_cleanup_ucontext+0x2f0/0x730
 ? sched_clock_cpu+0x18/0x200
 ? uverbs_close_fd+0x1c0/0x1c0
 ib_uverbs_cleanup_ucontext.constprop.3+0x52/0x120
 ib_uverbs_close+0xf2/0x570
 ? ib_uverbs_remove_one+0xb50/0xb50
 ? ib_uverbs_remove_one+0xb50/0xb50
 __fput+0x2cd/0x8d0
 task_work_run+0xec/0x1d0
 do_exit+0x6a1/0x1520
 ? fsnotify_first_mark+0x220/0x220
 ? exit_notify+0x9f0/0x9f0
 ? entry_SYSCALL_64_fastpath+0x5/0x8b
 ? entry_SYSCALL_64_fastpath+0x5/0x8b
 ? trace_hardirqs_on_thunk+0x1a/0x1c
 ? time_hardirqs_on+0x27/0x670
 ? time_hardirqs_off+0x27/0x490
 ? syscall_return_slowpath+0x6c/0x460
 ? entry_SYSCALL_64_fastpath+0x5/0x8b
 do_group_exit+0xe8/0x380
 SyS_exit_group+0x1e/0x20
 entry_SYSCALL_64_fastpath+0x1e/0x8b
RIP: 0033:0x431ce9

---
 drivers/infiniband/core/uverbs_cmd.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

index 1187b757d911..6941faaaf1c3 100644
@@ -562,9 +562,10 @@ ssize_t ib_uverbs_open_xrcd(struct ib_uverbs_file *file,
 	if (f.file)
 		fdput(f);
 
+	mutex_unlock(&file->device->xrcd_tree_mutex);
+
 	uobj_alloc_commit(&obj->uobject);
 
-	mutex_unlock(&file->device->xrcd_tree_mutex);
 	return in_len;
 
 err_copy:

2.16.1

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From: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/[email protected]>

==================================================================

BUG: KASAN: use-after-free in copy_ah_attr_from_uverbs+0x6f2/0x8c0
Read of size 4 at addr ffff88006476a198 by task syzkaller697701/265

CPU: 0 PID: 265 Comm: syzkaller697701 Not tainted 4.15.0+ #90
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014
Call Trace:
 dump_stack+0xde/0x164
 ? dma_virt_map_sg+0x22c/0x22c
 ? show_regs_print_info+0x17/0x17
 ? lock_contended+0x11a0/0x11a0
 print_address_description+0x83/0x3e0
 kasan_report+0x18c/0x4b0
 ? copy_ah_attr_from_uverbs+0x6f2/0x8c0
 ? copy_ah_attr_from_uverbs+0x6f2/0x8c0
 ? lookup_get_idr_uobject+0x120/0x200
 ? copy_ah_attr_from_uverbs+0x6f2/0x8c0
 copy_ah_attr_from_uverbs+0x6f2/0x8c0
 ? modify_qp+0xd0e/0x1350
 modify_qp+0xd0e/0x1350
 ib_uverbs_modify_qp+0xf9/0x170
 ? ib_uverbs_query_qp+0xa70/0xa70
 ib_uverbs_write+0x7f9/0xef0
 ? attach_entity_load_avg+0x8b0/0x8b0
 ? ib_uverbs_query_qp+0xa70/0xa70
 ? uverbs_devnode+0x110/0x110
 ? cyc2ns_read_end+0x10/0x10
 ? print_irqtrace_events+0x280/0x280
 ? sched_clock_cpu+0x18/0x200
 ? _raw_spin_unlock_irq+0x29/0x40
 ? _raw_spin_unlock_irq+0x29/0x40
 ? _raw_spin_unlock_irq+0x29/0x40
 ? time_hardirqs_on+0x27/0x670
 __vfs_write+0x10d/0x700
 ? uverbs_devnode+0x110/0x110
 ? kernel_read+0x170/0x170
 ? _raw_spin_unlock_irq+0x29/0x40
 ? finish_task_switch+0x1bd/0x7a0
 ? finish_task_switch+0x194/0x7a0
 ? prandom_u32_state+0xe/0x180
 ? rcu_read_unlock+0x80/0x80
 ? security_file_permission+0x93/0x260
 vfs_write+0x1b0/0x550
 SyS_write+0xc7/0x1a0
 ? SyS_read+0x1a0/0x1a0
 ? trace_hardirqs_on_thunk+0x1a/0x1c
 entry_SYSCALL_64_fastpath+0x1e/0x8b
RIP: 0033:0x433c29
RSP: 002b:00007ffcf2be82a8 EFLAGS: 00000217

Allocated by task 62:
 kasan_kmalloc+0xa0/0xd0
 kmem_cache_alloc+0x141/0x480
 dup_fd+0x101/0xcc0
 copy_process.part.62+0x166f/0x4390
 _do_fork+0x1cb/0xe90
 kernel_thread+0x34/0x40
 call_usermodehelper_exec_work+0x112/0x260
 process_one_work+0x929/0x1aa0
 worker_thread+0x5c6/0x12a0
 kthread+0x346/0x510
 ret_from_fork+0x3a/0x50

Freed by task 259:
 kasan_slab_free+0x71/0xc0
 kmem_cache_free+0xf3/0x4c0
 put_files_struct+0x225/0x2c0
 exit_files+0x88/0xc0
 do_exit+0x67c/0x1520
 do_group_exit+0xe8/0x380
 SyS_exit_group+0x1e/0x20
 entry_SYSCALL_64_fastpath+0x1e/0x8b

The buggy address belongs to the object at ffff88006476a000
 which belongs to the cache files_cache of size 832
The buggy address is located 408 bytes inside of
 832-byte region [ffff88006476a000, ffff88006476a340)
The buggy address belongs to the page:
page:ffffea000191da80 count:1 mapcount:0 mapping:          (null) index:0x0 compound_mapcount: 0
flags: 0x4000000000008100(slab|head)
raw: 4000000000008100 0000000000000000 0000000000000000 0000000100080008
raw: 0000000000000000 0000000100000001 ffff88006bcf7a80 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88006476a080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88006476a100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88006476a180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff88006476a200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88006476a280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

---
 drivers/infiniband/core/uverbs_cmd.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

index 6941faaaf1c3..cd9fbd7c82b0 100644
@@ -1970,8 +1970,15 @@ static int modify_qp(struct ib_uverbs_file *file,
 		goto release_qp;
 	}
 
+	if ((cmd->base.attr_mask & IB_QP_AV) &&
+	    !rdma_is_port_valid(qp->device, cmd->base.dest.port_num)) {
+		ret = -EINVAL;
+		goto release_qp;
+	}
+
 	if ((cmd->base.attr_mask & IB_QP_ALT_PATH) &&
-	    !rdma_is_port_valid(qp->device, cmd->base.alt_port_num)) {
+	    (!rdma_is_port_valid(qp->device, cmd->base.alt_port_num) ||
+	    !rdma_is_port_valid(qp->device, cmd->base.alt_dest.port_num))) {
 		ret = -EINVAL;
 		goto release_qp;
 	}

2.16.1

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I applied all of these to for-rc, thanks

Jasno
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