Subject: [PATCH] net: ipv4: fib_semantics: fix uninitialized variable

From: Enrico Weigelt <[email protected]>

fix an uninitialized variable:

CC net/ipv4/fib_semantics.o
net/ipv4/fib_semantics.c: In function 'fib_check_nh_v4_gw':
net/ipv4/fib_semantics.c:1027:12: warning: 'err' may be used uninitialized in this function [-Wmaybe-uninitialized]
if (!tbl || err) {
^~

Signed-off-by: Enrico Weigelt <[email protected]>
---
net/ipv4/fib_semantics.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index b804106..bfa49a8 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -964,7 +964,7 @@ static int fib_check_nh_v4_gw(struct net *net, struct fib_nh *nh, u32 table,
{
struct net_device *dev;
struct fib_result res;
- int err;
+ int err = 0;

if (nh->fib_nh_flags & RTNH_F_ONLINK) {
unsigned int addr_type;
--
1.9.1


2019-06-06 19:39:44

by David Ahern

[permalink] [raw]
Subject: Re: [PATCH] net: ipv4: fib_semantics: fix uninitialized variable

On 6/6/19 8:43 AM, Enrico Weigelt, metux IT consult wrote:
> From: Enrico Weigelt <[email protected]>
>
> fix an uninitialized variable:
>
> CC net/ipv4/fib_semantics.o
> net/ipv4/fib_semantics.c: In function 'fib_check_nh_v4_gw':
> net/ipv4/fib_semantics.c:1027:12: warning: 'err' may be used uninitialized in this function [-Wmaybe-uninitialized]
> if (!tbl || err) {
> ^~
>
> Signed-off-by: Enrico Weigelt <[email protected]>
> ---
> net/ipv4/fib_semantics.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
> index b804106..bfa49a8 100644
> --- a/net/ipv4/fib_semantics.c
> +++ b/net/ipv4/fib_semantics.c
> @@ -964,7 +964,7 @@ static int fib_check_nh_v4_gw(struct net *net, struct fib_nh *nh, u32 table,
> {
> struct net_device *dev;
> struct fib_result res;
> - int err;
> + int err = 0;
>
> if (nh->fib_nh_flags & RTNH_F_ONLINK) {
> unsigned int addr_type;
>

what compiler version?

if tbl is set, then err is set.

2019-06-06 20:16:53

by David Miller

[permalink] [raw]
Subject: Re: [PATCH] net: ipv4: fib_semantics: fix uninitialized variable

From: David Ahern <[email protected]>
Date: Thu, 6 Jun 2019 09:47:34 -0600

> On 6/6/19 8:43 AM, Enrico Weigelt, metux IT consult wrote:
>> From: Enrico Weigelt <[email protected]>
>>
>> fix an uninitialized variable:
>>
>> CC net/ipv4/fib_semantics.o
>> net/ipv4/fib_semantics.c: In function 'fib_check_nh_v4_gw':
>> net/ipv4/fib_semantics.c:1027:12: warning: 'err' may be used uninitialized in this function [-Wmaybe-uninitialized]
>> if (!tbl || err) {
>> ^~
>>
>> Signed-off-by: Enrico Weigelt <[email protected]>
>> ---
>> net/ipv4/fib_semantics.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
>> index b804106..bfa49a8 100644
>> --- a/net/ipv4/fib_semantics.c
>> +++ b/net/ipv4/fib_semantics.c
>> @@ -964,7 +964,7 @@ static int fib_check_nh_v4_gw(struct net *net, struct fib_nh *nh, u32 table,
>> {
>> struct net_device *dev;
>> struct fib_result res;
>> - int err;
>> + int err = 0;
>>
>> if (nh->fib_nh_flags & RTNH_F_ONLINK) {
>> unsigned int addr_type;
>>
>
> what compiler version?
>
> if tbl is set, then err is set.

It's unfortunate that it can't walk through that simple logic and set
of dependencies but we'll have to quiet this warning whether we like it
or not.

Subject: Re: [PATCH] net: ipv4: fib_semantics: fix uninitialized variable

On 06.06.19 17:47, David Ahern wrote:
>
> what compiler version?
>
> if tbl is set, then err is set.
>

gcc (Debian 6.3.0-18+deb9u1) 6.3.0 20170516

--
Enrico Weigelt, metux IT consult
Free software and Linux embedded engineering
[email protected] -- +49-151-27565287

2019-06-09 19:49:17

by David Miller

[permalink] [raw]
Subject: Re: [PATCH] net: ipv4: fib_semantics: fix uninitialized variable

From: "Enrico Weigelt, metux IT consult" <[email protected]>
Date: Thu, 6 Jun 2019 16:43:17 +0200

> From: Enrico Weigelt <[email protected]>
>
> fix an uninitialized variable:
>
> CC net/ipv4/fib_semantics.o
> net/ipv4/fib_semantics.c: In function 'fib_check_nh_v4_gw':
> net/ipv4/fib_semantics.c:1027:12: warning: 'err' may be used uninitialized in this function [-Wmaybe-uninitialized]
> if (!tbl || err) {
> ^~
>
> Signed-off-by: Enrico Weigelt <[email protected]>

Applied.