[Drbd-dev] [PATCH] drbd: Fix exception handling in nla_put_drbd_cfg_context()

Markus Elfring Markus.Elfring at web.de
Fri Mar 17 18:40:35 CET 2023

Date: Fri, 17 Mar 2023 18:32:05 +0100

The label “nla_put_failure” was used to jump to another pointer check
despite of the detail in the implementation of the function
“nla_put_drbd_cfg_context” that it was determined already that
the corresponding variable contained a null pointer.

* Thus return directly after a call of the function
  “nla_nest_start_noflag” failed.

* Delete an extra pointer check which became unnecessary
  with this refactoring.

This issue was detected by using the Coccinelle software.

Fixes: 543cc10b4cc5c60aa9fcc62705ccfb9998bf4697 ("drbd: drbd_adm_get_status needs to show some more detail")
Signed-off-by: Markus Elfring <elfring at users.sourceforge.net>
 drivers/block/drbd/drbd_nl.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index f49f2a5282e1..9cb947127472 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -3187,7 +3187,7 @@ static int nla_put_drbd_cfg_context(struct sk_buff *skb,
     struct nlattr *nla;
     nla = nla_nest_start_noflag(skb, DRBD_NLA_CFG_CONTEXT);
     if (!nla)
-        goto nla_put_failure;
+        return -EMSGSIZE;
     if (device &&
         nla_put_u32(skb, T_ctx_volume, device->vnr))
         goto nla_put_failure;
@@ -3205,8 +3205,7 @@ static int nla_put_drbd_cfg_context(struct sk_buff *skb,
     return 0;
-    if (nla)
-        nla_nest_cancel(skb, nla);
+    nla_nest_cancel(skb, nla);
     return -EMSGSIZE;

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