[PATCH] RDMA/irdma: Fix UAF in irdma_sc_ccq_get_cqe_info()

[Shifeng Li]

When removing the irdma driver or unplugging its aux device, the ccq
queue is released before destorying the cqp_cmpl_wq queue.
But in the window, there may still be completion events for wqes. That
will cause a UAF in irdma_sc_ccq_get_cqe_info().

[34693.333191] BUG: KASAN: use-after-free in irdma_sc_ccq_get_cqe_info+0x82f/0x8c0 [irdma]
[34693.333194] Read of size 8 at addr ffff889097f80818 by task kworker/u67:1/26327
[34693.333194]
[34693.333199] CPU: 9 PID: 26327 Comm: kworker/u67:1 Kdump: loaded Tainted: G           O     --------- -t - 4.18.0 #1
[34693.333200] Hardware name: SANGFOR Inspur/NULL, BIOS 4.1.13 08/01/2016
[34693.333211] Workqueue: cqp_cmpl_wq cqp_compl_worker [irdma]
[34693.333213] Call Trace:
[34693.333220]  dump_stack+0x71/0xab
[34693.333226]  print_address_description+0x6b/0x290
[34693.333238]  ? irdma_sc_ccq_get_cqe_info+0x82f/0x8c0 [irdma]
[34693.333240]  kasan_report+0x14a/0x2b0
[34693.333251]  irdma_sc_ccq_get_cqe_info+0x82f/0x8c0 [irdma]
[34693.333264]  ? irdma_free_cqp_request+0x151/0x1e0 [irdma]
[34693.333274]  irdma_cqp_ce_handler+0x1fb/0x3b0 [irdma]
[34693.333285]  ? irdma_ctrl_init_hw+0x2c20/0x2c20 [irdma]
[34693.333290]  ? __schedule+0x836/0x1570
[34693.333293]  ? strscpy+0x83/0x180
[34693.333296]  process_one_work+0x56a/0x11f0
[34693.333298]  worker_thread+0x8f/0xf40
[34693.333301]  ? __kthread_parkme+0x78/0xf0
[34693.333303]  ? rescuer_thread+0xc50/0xc50
[34693.333305]  kthread+0x2a0/0x390
[34693.333308]  ? kthread_destroy_worker+0x90/0x90
[34693.333310]  ret_from_fork+0x1f/0x40

Signed-off-by: Shifeng Li <lishifeng1992@xxxxxxx>
---
 drivers/infiniband/hw/irdma/hw.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/hw/irdma/hw.c b/drivers/infiniband/hw/irdma/hw.c
index ab246447520b..de7337a6a874 100644
--- a/drivers/infiniband/hw/irdma/hw.c
+++ b/drivers/infiniband/hw/irdma/hw.c
@@ -570,8 +570,6 @@ static void irdma_destroy_cqp(struct irdma_pci_f *rf, bool free_hwcqp)
 	struct irdma_cqp *cqp = &rf->cqp;
 	int status = 0;
 
-	if (rf->cqp_cmpl_wq)
-		destroy_workqueue(rf->cqp_cmpl_wq);
 	if (free_hwcqp)
 		status = irdma_sc_cqp_destroy(dev->cqp);
 	if (status)
@@ -737,6 +735,8 @@ static void irdma_destroy_ccq(struct irdma_pci_f *rf)
 	struct irdma_ccq *ccq = &rf->ccq;
 	int status = 0;
 
+	if (rf->cqp_cmpl_wq)
+		destroy_workqueue(rf->cqp_cmpl_wq);
 	if (!rf->reset)
 		status = irdma_sc_ccq_destroy(dev->ccq, 0, true);
 	if (status)
-- 
2.25.1