net/mlx5e: Fix crash caused by calling __xfrm_state_delete() twice

The km.state is not checked in driver's delayed work. When
xfrm_state_check_expire() is called, the state can be reset to
XFRM_STATE_EXPIRED, even if it is XFRM_STATE_DEAD already. This
happens when xfrm state is deleted, but not freed yet. As
__xfrm_state_delete() is called again in xfrm timer, the following
crash occurs.

To fix this issue, skip xfrm_state_check_expire() if km.state is not
XFRM_STATE_VALID.

 Oops: general protection fault, probably for non-canonical address 0xdead000000000108: 0000 [#1] SMP
 CPU: 5 UID: 0 PID: 7448 Comm: kworker/u102:2 Not tainted 6.11.0-rc2+ #1
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
 Workqueue: mlx5e_ipsec: eth%d mlx5e_ipsec_handle_sw_limits [mlx5_core]
 RIP: 0010:__xfrm_state_delete+0x3d/0x1b0
 Code: 0f 84 8b 01 00 00 48 89 fd c6 87 c8 00 00 00 05 48 8d bb 40 10 00 00 e8 11 04 1a 00 48 8b 95 b8 00 00 00 48 8b 85 c0 00 00 00 <48> 89 42 08 48 89 10 48 8b 55 10 48 b8 00 01 00 00 00 00 ad de 48
 RSP: 0018:ffff88885f945ec8 EFLAGS: 00010246
 RAX: dead000000000122 RBX: ffffffff82afa940 RCX: 0000000000000036
 RDX: dead000000000100 RSI: 0000000000000000 RDI: ffffffff82afb980
 RBP: ffff888109a20340 R08: ffff88885f945ea0 R09: 0000000000000000
 R10: 0000000000000000 R11: ffff88885f945ff8 R12: 0000000000000246
 R13: ffff888109a20340 R14: ffff88885f95f420 R15: ffff88885f95f400
 FS:  0000000000000000(0000) GS:ffff88885f940000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f2163102430 CR3: 00000001128d6001 CR4: 0000000000370eb0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
  <IRQ>
  ? die_addr+0x33/0x90
  ? exc_general_protection+0x1a2/0x390
  ? asm_exc_general_protection+0x22/0x30
  ? __xfrm_state_delete+0x3d/0x1b0
  ? __xfrm_state_delete+0x2f/0x1b0
  xfrm_timer_handler+0x174/0x350
  ? __xfrm_state_delete+0x1b0/0x1b0
  __hrtimer_run_queues+0x121/0x270
  hrtimer_run_softirq+0x88/0xd0
  handle_softirqs+0xcc/0x270
  do_softirq+0x3c/0x50
  </IRQ>
  <TASK>
  __local_bh_enable_ip+0x47/0x50
  mlx5e_ipsec_handle_sw_limits+0x7d/0x90 [mlx5_core]
  process_one_work+0x137/0x2d0
  worker_thread+0x28d/0x3a0
  ? rescuer_thread+0x480/0x480
  kthread+0xb8/0xe0
  ? kthread_park+0x80/0x80
  ret_from_fork+0x2d/0x50
  ? kthread_park+0x80/0x80
  ret_from_fork_asm+0x11/0x20
  </TASK>

Fixes: b2f7b01 ("net/mlx5e: Simulate missing IPsec TX limits hardware functionality")
Signed-off-by: Jianbo Liu <[email protected]>
Reviewed-by: Leon Romanovsky <[email protected]>
Signed-off-by: Saeed Mahameed <[email protected]>

drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c

@@ -67,14 +67,20 @@ static void mlx5e_ipsec_handle_sw_limits(struct work_struct *_work)
 		return;
 
 	spin_lock_bh(&x->lock);
-	xfrm_state_check_expire(x);
 	if (x->km.state == XFRM_STATE_EXPIRED) {
 		sa_entry->attrs.drop = true;
 		spin_unlock_bh(&x->lock);
 
 		mlx5e_accel_ipsec_fs_modify(sa_entry);
 		return;
 	}
+
+	if (x->km.state != XFRM_STATE_VALID) {
+		spin_unlock_bh(&x->lock);
+		return;
+	}
+
+	xfrm_state_check_expire(x);
 	spin_unlock_bh(&x->lock);
 
 	queue_delayed_work(sa_entry->ipsec->wq, &dwork->dwork,