Make use of the struct_size() helper instead of an open-coded version,
in order to avoid any potential type mistakes or integer overflows
that, in the worst scenario, could lead to heap overflows.

Link: https://github.com/KSPP/linux/issues/160
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
  drivers/target/target_core_user.c | 3 +--
  1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index 9f552f48084c..dc220fad06fa 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c

@@ -1255,7 +1255,6 @@ tcmu_tmr_notify(struct se_device *se_dev, enum tcm_tmreq_table tmf,
  {
  	int i = 0, cmd_cnt = 0;
  	bool unqueued = false;
-	uint16_t *cmd_ids = NULL;
  	struct tcmu_cmd *cmd;
  	struct se_cmd *se_cmd;
  	struct tcmu_tmr *tmr;

@@ -1292,7 +1291,7 @@ tcmu_tmr_notify(struct se_device *se_dev, enum tcm_tmreq_table tmf,
  	pr_debug("TMR event %d on dev %s, aborted cmds %d, afflicted cmd_ids %d\n",
  		 tcmu_tmr_type(tmf), udev->name, i, cmd_cnt);
  
-	tmr = kmalloc(sizeof(*tmr) + cmd_cnt * sizeof(*cmd_ids), GFP_NOIO);
+	tmr = kmalloc(struct_size(tmr, tmr_cmd_ids, cmd_cnt), GFP_NOIO);
  	if (!tmr)
  		goto unlock;