RDMA/bnxt_re: Fix a possible memory leak in the driver

The GID context reuse logic requires the context memory to be
not freed if and when DEL_GID firmware command fails. But, if
there's no subsequent ADD_GID to reuse it, the context memory
must be freed when the driver is unloaded. Otherwise it leads
to a memory leak.

Below is the kmemleak trace reported:

unreferenced object 0xffff88817a4f34d0 (size 8):
  comm "insmod", pid 1072504, jiffies 4402561550
  hex dump (first 8 bytes):
  01 00 00 00 00 00 00 00                          ........
  backtrace (crc ccaa009e):
  __kmalloc_cache_noprof+0x33e/0x400
  0xffffffffc2db9d48
  add_modify_gid+0x5e0/0xb60 [ib_core]
  __ib_cache_gid_add+0x213/0x350 [ib_core]
  update_gid+0xf2/0x180 [ib_core]
  enum_netdev_ipv4_ips+0x3f3/0x690 [ib_core]
  enum_all_gids_of_dev_cb+0x125/0x1b0 [ib_core]
  ib_enum_roce_netdev+0x14b/0x250 [ib_core]
  ib_cache_setup_one+0x2e5/0x540 [ib_core]
  ib_register_device+0x82c/0xf10 [ib_core]
  0xffffffffc2df5ad9
  0xffffffffc2da8b07
  0xffffffffc2db174d
  auxiliary_bus_probe+0xa5/0x120
  really_probe+0x1e4/0x850
  __driver_probe_device+0x18f/0x3d0

Fixes: 4a62c5e ("RDMA/bnxt_re: Do not free the ctx_tbl entry if delete GID fails")
Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Link: https://patch.msgid.link/20250805101000.233310-4-kalesh-anakkur.purayil@broadcom.com
Reviewed-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

Author: Kalesh AP

drivers/infiniband/hw/bnxt_re/main.c

@@ -2017,6 +2017,28 @@ static void bnxt_re_free_nqr_mem(struct bnxt_re_dev *rdev)
 	rdev->nqr = NULL;
 }
 
+/* When DEL_GID fails, driver is not freeing GID ctx memory.
+ * To avoid the memory leak, free the memory during unload
+ */
+static void bnxt_re_free_gid_ctx(struct bnxt_re_dev *rdev)
+{
+	struct bnxt_qplib_sgid_tbl *sgid_tbl = &rdev->qplib_res.sgid_tbl;
+	struct bnxt_re_gid_ctx *ctx, **ctx_tbl;
+	int i;
+
+	if (!sgid_tbl->active)
+		return;
+
+	ctx_tbl = sgid_tbl->ctx;
+	for (i = 0; i < sgid_tbl->max; i++) {
+		if (sgid_tbl->hw_id[i] == 0xFFFF)
+			continue;
+
+		ctx = ctx_tbl[i];
+		kfree(ctx);
+	}
+}
+
 static void bnxt_re_dev_uninit(struct bnxt_re_dev *rdev, u8 op_type)
 {
 	u8 type;
@@ -2030,6 +2052,7 @@ static void bnxt_re_dev_uninit(struct bnxt_re_dev *rdev, u8 op_type)
 	if (test_and_clear_bit(BNXT_RE_FLAG_QOS_WORK_REG, &rdev->flags))
 		cancel_delayed_work_sync(&rdev->worker);
 
+	bnxt_re_free_gid_ctx(rdev);
 	if (test_and_clear_bit(BNXT_RE_FLAG_RESOURCES_INITIALIZED,
 			       &rdev->flags))
 		bnxt_re_cleanup_res(rdev);