[PATCH v2] net: Fix uninit character pointer and return values

[PATCH v2] net: Fix uninit character pointer and return values

[Sidharth Seela]

Fix uninitialized character pointer, and functions that return
undefined values. These issues were caught by running clang using LLVM=1
option; and are as follows:
--
ovpn-cli.c:1587:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
 1587 |         if (!sock) {
      |             ^~~~~
ovpn-cli.c:1635:9: note: uninitialized use occurs here
 1635 |         return ret;
      |                ^~~
ovpn-cli.c:1587:2: note: remove the 'if' if its condition is always false
 1587 |         if (!sock) {
      |         ^~~~~~~~~~~~
 1588 |                 fprintf(stderr, "cannot allocate netlink socket\n");
      |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 1589 |                 goto err_free;
      |                 ~~~~~~~~~~~~~~
 1590 |         }
      |         ~
ovpn-cli.c:1584:15: note: initialize the variable 'ret' to silence this warning
 1584 |         int mcid, ret;
      |                      ^
      |                       = 0
ovpn-cli.c:2107:7: warning: variable 'ret' is used uninitialized whenever switch case is taken [-Wsometimes-uninitialized]
 2107 |         case CMD_INVALID:
      |              ^~~~~~~~~~~
ovpn-cli.c:2111:9: note: uninitialized use occurs here
 2111 |         return ret;
      |                ^~~
ovpn-cli.c:1939:12: note: initialize the variable 'ret' to silence this warning
 1939 |         int n, ret;
      |                   ^
      |
--
so_txtime.c:210:3: warning: variable 'reason' is used uninitialized whenever switch default is taken [-Wsometimes-uninitialized]
  210 |                 default:
      |                 ^~~~~~~
so_txtime.c:219:27: note: uninitialized use occurs here
  219 |                         data[ret - 1], tstamp, reason);
      |                                                ^~~~~~
so_txtime.c:177:21: note: initialize the variable 'reason' to silence this warning
  177 |                 const char *reason;
      |                                   ^
      |
--
Fixes: 959bc330a439 ("testing/selftests: add test tool and scripts for ovpn module")
ovpn module")
Fixes: ca8826095e4d4 ("selftests/net: report etf errors correctly")

Signed-off-by: Sidharth Seela <sidharthseela@gmail.com>

v2:
	- Use subsystem name "net".
	- Add fixes tags.
	- Remove txtimestamp fix as default case calls error.
	- Assign constant error string instead of NULL.
--

diff --git a/tools/testing/selftests/net/ovpn/ovpn-cli.c b/tools/testing/selftests/net/ovpn/ovpn-cli.c
index 9201f2905f2c..20d00378f34a 100644
--- a/tools/testing/selftests/net/ovpn/ovpn-cli.c
+++ b/tools/testing/selftests/net/ovpn/ovpn-cli.c
@@ -1581,7 +1581,7 @@ static int ovpn_listen_mcast(void)
 {
 	struct nl_sock *sock;
 	struct nl_cb *cb;
-	int mcid, ret;
+	int mcid, ret = -1;
 
 	sock = nl_socket_alloc();
 	if (!sock) {
@@ -1936,7 +1936,7 @@ static int ovpn_run_cmd(struct ovpn_ctx *ovpn)
 {
 	char peer_id[10], vpnip[INET6_ADDRSTRLEN], laddr[128], lport[10];
 	char raddr[128], rport[10];
-	int n, ret;
+	int n, ret = -1;
 	FILE *fp;
 
 	switch (ovpn->cmd) {
diff --git a/tools/testing/selftests/net/so_txtime.c b/tools/testing/selftests/net/so_txtime.c
index 8457b7ccbc09..5bf3c483069b 100644
--- a/tools/testing/selftests/net/so_txtime.c
+++ b/tools/testing/selftests/net/so_txtime.c
@@ -174,7 +174,7 @@ static int do_recv_errqueue_timeout(int fdt)
 	msg.msg_controllen = sizeof(control);
 
 	while (1) {
-		const char *reason;
+		const char *reason = "unknown errno";
 
 		ret = recvmsg(fdt, &msg, MSG_ERRQUEUE);
 		if (ret == -1 && errno == EAGAIN)
-- 
2.47.3

Re: [PATCH v2] net: Fix uninit character pointer and return values

[Willem de Bruijn]

Reminder: use the net prefix: [PATCH net v2]

Sidharth Seela wrote:
> Fix uninitialized character pointer, and functions that return
> undefined values. These issues were caught by running clang using LLVM=1
> option; and are as follows:
> --
> ovpn-cli.c:1587:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
>  1587 |         if (!sock) {
>       |             ^~~~~
> ovpn-cli.c:1635:9: note: uninitialized use occurs here
>  1635 |         return ret;
>       |                ^~~
> ovpn-cli.c:1587:2: note: remove the 'if' if its condition is always false
>  1587 |         if (!sock) {
>       |         ^~~~~~~~~~~~
>  1588 |                 fprintf(stderr, "cannot allocate netlink socket\n");
>       |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>  1589 |                 goto err_free;
>       |                 ~~~~~~~~~~~~~~
>  1590 |         }
>       |         ~
> ovpn-cli.c:1584:15: note: initialize the variable 'ret' to silence this warning
>  1584 |         int mcid, ret;
>       |                      ^
>       |                       = 0
> ovpn-cli.c:2107:7: warning: variable 'ret' is used uninitialized whenever switch case is taken [-Wsometimes-uninitialized]
>  2107 |         case CMD_INVALID:
>       |              ^~~~~~~~~~~
> ovpn-cli.c:2111:9: note: uninitialized use occurs here
>  2111 |         return ret;
>       |                ^~~
> ovpn-cli.c:1939:12: note: initialize the variable 'ret' to silence this warning
>  1939 |         int n, ret;
>       |                   ^
>       |
> --
> so_txtime.c:210:3: warning: variable 'reason' is used uninitialized whenever switch default is taken [-Wsometimes-uninitialized]
>   210 |                 default:
>       |                 ^~~~~~~
> so_txtime.c:219:27: note: uninitialized use occurs here
>   219 |                         data[ret - 1], tstamp, reason);
>       |                                                ^~~~~~
> so_txtime.c:177:21: note: initialize the variable 'reason' to silence this warning
>   177 |                 const char *reason;
>       |                                   ^
>       |

My previous response accidentally left a state comment. The main
feedback still held:

This default case calls error() and exits the program, so this cannot
happen.

> --
> Fixes: 959bc330a439 ("testing/selftests: add test tool and scripts for ovpn module")
> ovpn module")
> Fixes: ca8826095e4d4 ("selftests/net: report etf errors correctly")
> 
> Signed-off-by: Sidharth Seela <sidharthseela@gmail.com>
> 
> v2:
> 	- Use subsystem name "net".
> 	- Add fixes tags.
> 	- Remove txtimestamp fix as default case calls error.
> 	- Assign constant error string instead of NULL.
> --

End the commit with the Signed-off-by block. Either move changelog
above that, or below three (not two) dashes.
 
> diff --git a/tools/testing/selftests/net/ovpn/ovpn-cli.c b/tools/testing/selftests/net/ovpn/ovpn-cli.c
> index 9201f2905f2c..20d00378f34a 100644
> --- a/tools/testing/selftests/net/ovpn/ovpn-cli.c
> +++ b/tools/testing/selftests/net/ovpn/ovpn-cli.c
> @@ -1581,7 +1581,7 @@ static int ovpn_listen_mcast(void)
>  {
>  	struct nl_sock *sock;
>  	struct nl_cb *cb;
> -	int mcid, ret;
> +	int mcid, ret = -1;
>  
>  	sock = nl_socket_alloc();
>  	if (!sock) {
> @@ -1936,7 +1936,7 @@ static int ovpn_run_cmd(struct ovpn_ctx *ovpn)
>  {
>  	char peer_id[10], vpnip[INET6_ADDRSTRLEN], laddr[128], lport[10];
>  	char raddr[128], rport[10];
> -	int n, ret;
> +	int n, ret = -1;
>  	FILE *fp;
>  
>  	switch (ovpn->cmd) {
> diff --git a/tools/testing/selftests/net/so_txtime.c b/tools/testing/selftests/net/so_txtime.c
> index 8457b7ccbc09..5bf3c483069b 100644
> --- a/tools/testing/selftests/net/so_txtime.c
> +++ b/tools/testing/selftests/net/so_txtime.c
> @@ -174,7 +174,7 @@ static int do_recv_errqueue_timeout(int fdt)
>  	msg.msg_controllen = sizeof(control);
>  
>  	while (1) {
> -		const char *reason;
> +		const char *reason = "unknown errno";
>  
>  		ret = recvmsg(fdt, &msg, MSG_ERRQUEUE);
>  		if (ret == -1 && errno == EAGAIN)
> -- 
> 2.47.3
> 

Re: [PATCH v2] net: Fix uninit character pointer and return values

[Sidharth Seela]

On Mon, Sep 29, 2025 at 11:28 PM Willem de Bruijn
<willemdebruijn.kernel@gmail.com> wrote:
>
> Reminder: use the net prefix: [PATCH net v2]
Oh I thought you meant me to change the subsytem in the subject.
Changing.

> My previous response accidentally left a state comment. The main
> feedback still held:
> This default case calls error() and exits the program, so this cannot
> happen.
Alright, I thought error() is like perror(). After checking man pages, the
status being non-zero leads to exit(). So yes, it makes sense now, the
switch case, either loads up a value in the 'reason' or exits().

> End the commit with the Signed-off-by block. Either move changelog
> above that, or below three (not two) dashes.
Alright, Thank you for taking the time to reply. Sending w/ changes.

-- 
Thanks,
Sidharth Seela
www.realtimedesign.org