FORWARD_NULL Vs UNINIT Coverity errors in C
0
when a pointer is initialized to NULL, getting "FORWARD_NULL" coverity errors and when the NULL initialization is removed, it throws UNINIT coverity errors. The code is as below.
I am very new to coverity. If its a very basic question also, please help.
I am
1) declaring a pointer,
2) Initializing it to NULL and
3) deferring it without assigning anything to it.
This deference is an argument in a function call inside which, it will be filled in. Getting FORWARD_NULL errors for the same. Started with Coverity works, from yesterday only.
int fn1()
{
strct1 *pvarA = NULL;
if (fn2(&pvarA) != 0) // derefering NULL pointer error.
{
return 1;
}
...
/* some code */
}
int fn2(strct1 **pvarA)
{
...
/* some code */
*pvarA = varA;
/* some code */
return 0;
}
Thanks,
Preethi
c coverity
asked Nov 13 '18 at 11:59
PreethiPreethi
67211
add a comment |
0
when a pointer is initialized to NULL, getting "FORWARD_NULL" coverity errors and when the NULL initialization is removed, it throws UNINIT coverity errors. The code is as below.
I am very new to coverity. If its a very basic question also, please help.
I am
1) declaring a pointer,
2) Initializing it to NULL and
3) deferring it without assigning anything to it.
This deference is an argument in a function call inside which, it will be filled in. Getting FORWARD_NULL errors for the same. Started with Coverity works, from yesterday only.
int fn1()
{
strct1 *pvarA = NULL;
if (fn2(&pvarA) != 0) // derefering NULL pointer error.
{
return 1;
}
...
/* some code */
}
int fn2(strct1 **pvarA)
{
...
/* some code */
*pvarA = varA;
/* some code */
return 0;
}
Thanks,
Preethi
c coverity
asked Nov 13 '18 at 11:59
PreethiPreethi
67211
1
How exactly does this code makes sense to you? As for why it complains if you drop the NULL, we cannot say without a Minimal, Complete, and Verifiable example. It could also be a tool bug, but none can tell with what's given here.
– Lundin
Nov 13 '18 at 12:04
1
FORWARD_NULL implies that you're dereferencing theNULL, but that's not what your code shows.
– Sander De Dycker
Nov 13 '18 at 12:21
Your code doesn't match your question. Did you mean*a = **ar?
– Jabberwocky
Nov 13 '18 at 12:29
Nope. It is matching. @Jabberwocky I wanted to doa = *ar. But in the lineint *a = NULL, getting coverity error as mentioned in the comments/* */
– Preethi
Nov 13 '18 at 13:32
add a comment |
0
0
0
when a pointer is initialized to NULL, getting "FORWARD_NULL" coverity errors and when the NULL initialization is removed, it throws UNINIT coverity errors. The code is as below.
I am very new to coverity. If its a very basic question also, please help.
I am
1) declaring a pointer,
2) Initializing it to NULL and
3) deferring it without assigning anything to it.
This deference is an argument in a function call inside which, it will be filled in. Getting FORWARD_NULL errors for the same. Started with Coverity works, from yesterday only.
int fn1()
{
strct1 *pvarA = NULL;
if (fn2(&pvarA) != 0) // derefering NULL pointer error.
{
return 1;
}
...
/* some code */
}
int fn2(strct1 **pvarA)
{
...
/* some code */
*pvarA = varA;
/* some code */
return 0;
}
Thanks,
Preethi
c coverity
asked Nov 13 '18 at 11:59
PreethiPreethi
67211
when a pointer is initialized to NULL, getting "FORWARD_NULL" coverity errors and when the NULL initialization is removed, it throws UNINIT coverity errors. The code is as below.
I am very new to coverity. If its a very basic question also, please help.
I am
1) declaring a pointer,
2) Initializing it to NULL and
3) deferring it without assigning anything to it.
This deference is an argument in a function call inside which, it will be filled in. Getting FORWARD_NULL errors for the same. Started with Coverity works, from yesterday only.
int fn1()
{
strct1 *pvarA = NULL;
if (fn2(&pvarA) != 0) // derefering NULL pointer error.
{
return 1;
}
...
/* some code */
}
int fn2(strct1 **pvarA)
{
...
/* some code */
*pvarA = varA;
/* some code */
return 0;
}
Thanks,
Preethi
c coverity
c coverity
asked Nov 13 '18 at 11:59
PreethiPreethi
67211
asked Nov 13 '18 at 11:59
PreethiPreethi
67211
edited Jan 24 at 14:28
Preethi
asked Nov 13 '18 at 11:59
PreethiPreethi
67211
asked Nov 13 '18 at 11:59
PreethiPreethi
67211
asked Nov 13 '18 at 11:59
PreethiPreethi
67211
67211
1
How exactly does this code makes sense to you? As for why it complains if you drop the NULL, we cannot say without a Minimal, Complete, and Verifiable example. It could also be a tool bug, but none can tell with what's given here.
– Lundin
Nov 13 '18 at 12:04
1
FORWARD_NULL implies that you're dereferencing theNULL, but that's not what your code shows.
– Sander De Dycker
Nov 13 '18 at 12:21
Your code doesn't match your question. Did you mean*a = **ar?
– Jabberwocky
Nov 13 '18 at 12:29
Nope. It is matching. @Jabberwocky I wanted to doa = *ar. But in the lineint *a = NULL, getting coverity error as mentioned in the comments/* */
– Preethi
Nov 13 '18 at 13:32
add a comment |
1
How exactly does this code makes sense to you? As for why it complains if you drop the NULL, we cannot say without a Minimal, Complete, and Verifiable example. It could also be a tool bug, but none can tell with what's given here.
– Lundin
Nov 13 '18 at 12:04
1
FORWARD_NULL implies that you're dereferencing theNULL, but that's not what your code shows.
– Sander De Dycker
Nov 13 '18 at 12:21
Your code doesn't match your question. Did you mean*a = **ar?
– Jabberwocky
Nov 13 '18 at 12:29
Nope. It is matching. @Jabberwocky I wanted to doa = *ar. But in the lineint *a = NULL, getting coverity error as mentioned in the comments/* */
– Preethi
Nov 13 '18 at 13:32
1
1
How exactly does this code makes sense to you? As for why it complains if you drop the NULL, we cannot say without a Minimal, Complete, and Verifiable example. It could also be a tool bug, but none can tell with what's given here.
– Lundin
Nov 13 '18 at 12:04
How exactly does this code makes sense to you? As for why it complains if you drop the NULL, we cannot say without a Minimal, Complete, and Verifiable example. It could also be a tool bug, but none can tell with what's given here.
– Lundin
Nov 13 '18 at 12:04
1
1
FORWARD_NULL implies that you're dereferencing the
NULL, but that's not what your code shows.– Sander De Dycker
Nov 13 '18 at 12:21
FORWARD_NULL implies that you're dereferencing the
NULL, but that's not what your code shows.– Sander De Dycker
Nov 13 '18 at 12:21
Your code doesn't match your question. Did you mean
*a = **ar?– Jabberwocky
Nov 13 '18 at 12:29
Your code doesn't match your question. Did you mean
*a = **ar?– Jabberwocky
Nov 13 '18 at 12:29
Nope. It is matching. @Jabberwocky I wanted to do
a = *ar. But in the line int *a = NULL, getting coverity error as mentioned in the comments /* */– Preethi
Nov 13 '18 at 13:32
Nope. It is matching. @Jabberwocky I wanted to do
a = *ar. But in the line int *a = NULL, getting coverity error as mentioned in the comments /* */– Preethi
Nov 13 '18 at 13:32
add a comment |
2 Answers
2
active
oldest
votes
2
In such code:
int fn1(int **ar)
{
int *a;
a = *ar;
}
The variable a is not initialized (thus UNINIT) and the variable ar is dereferenced without checking for null (thus FORWARD_NULL).
Probably this code will work:
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
int fn1(int **ar)
{
int *a = NULL;
if (ar == NULL) {
fprintf(stderr, "Omg! you passed NULL as first argument to fn1 function. What to do now? Break the program flow for sure - return or abort() or exit() !");
abort();
return EXIT_FAILURE;
}
a = *ar;
return EXIT_SUCCESS;
}
edited Jan 10 at 16:47
Paul Floyd
2,70811830
answered Nov 13 '18 at 12:23
Kamil CukKamil Cuk
10.3k1527
Thanks a lot. Trying it out. Once it is going to work, will update this as answer.
– Preethi
Nov 13 '18 at 13:07
I did this:int fn1(int **ar) { int *a = NULL; /* throws forward null, when NULL is removed, coverity throws unint errors. */ if (ar == NULL) { return 1;} a = *ar; }My coverity error still exists. @kamil
– Preethi
Nov 13 '18 at 13:24
add a comment |
0
This helps easily:
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
strct1
{
int a;
int b;
char c;
};
int fn1()
{
strct1 *pvarA = NULL;
strct1 varA;
MEMSET(&varA, 0, sizeof (strct1));
pvarA = &varA;
if (fn2(&pvarA) != 0) // derefering NULL pointer error.
{
return 1;
}
/* some code */
}
int fn2(strct1 **pvarA)
{
/* some code */
*pvarA = varA;
/* some code */
return 0;
}
answered Jan 24 at 14:53
PreethiPreethi
67211
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
2
In such code:
int fn1(int **ar)
{
int *a;
a = *ar;
}
The variable a is not initialized (thus UNINIT) and the variable ar is dereferenced without checking for null (thus FORWARD_NULL).
Probably this code will work:
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
int fn1(int **ar)
{
int *a = NULL;
if (ar == NULL) {
fprintf(stderr, "Omg! you passed NULL as first argument to fn1 function. What to do now? Break the program flow for sure - return or abort() or exit() !");
abort();
return EXIT_FAILURE;
}
a = *ar;
return EXIT_SUCCESS;
}
edited Jan 10 at 16:47
Paul Floyd
2,70811830
answered Nov 13 '18 at 12:23
Kamil CukKamil Cuk
10.3k1527
Thanks a lot. Trying it out. Once it is going to work, will update this as answer.
– Preethi
Nov 13 '18 at 13:07
I did this:int fn1(int **ar) { int *a = NULL; /* throws forward null, when NULL is removed, coverity throws unint errors. */ if (ar == NULL) { return 1;} a = *ar; }My coverity error still exists. @kamil
– Preethi
Nov 13 '18 at 13:24
add a comment |
2
In such code:
int fn1(int **ar)
{
int *a;
a = *ar;
}
The variable a is not initialized (thus UNINIT) and the variable ar is dereferenced without checking for null (thus FORWARD_NULL).
Probably this code will work:
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
int fn1(int **ar)
{
int *a = NULL;
if (ar == NULL) {
fprintf(stderr, "Omg! you passed NULL as first argument to fn1 function. What to do now? Break the program flow for sure - return or abort() or exit() !");
abort();
return EXIT_FAILURE;
}
a = *ar;
return EXIT_SUCCESS;
}
edited Jan 10 at 16:47
Paul Floyd
2,70811830
answered Nov 13 '18 at 12:23
Kamil CukKamil Cuk
10.3k1527
Thanks a lot. Trying it out. Once it is going to work, will update this as answer.
– Preethi
Nov 13 '18 at 13:07
I did this:int fn1(int **ar) { int *a = NULL; /* throws forward null, when NULL is removed, coverity throws unint errors. */ if (ar == NULL) { return 1;} a = *ar; }My coverity error still exists. @kamil
– Preethi
Nov 13 '18 at 13:24
add a comment |
2
2
2
In such code:
int fn1(int **ar)
{
int *a;
a = *ar;
}
The variable a is not initialized (thus UNINIT) and the variable ar is dereferenced without checking for null (thus FORWARD_NULL).
Probably this code will work:
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
int fn1(int **ar)
{
int *a = NULL;
if (ar == NULL) {
fprintf(stderr, "Omg! you passed NULL as first argument to fn1 function. What to do now? Break the program flow for sure - return or abort() or exit() !");
abort();
return EXIT_FAILURE;
}
a = *ar;
return EXIT_SUCCESS;
}
edited Jan 10 at 16:47
Paul Floyd
2,70811830
answered Nov 13 '18 at 12:23
Kamil CukKamil Cuk
10.3k1527
In such code:
int fn1(int **ar)
{
int *a;
a = *ar;
}
The variable a is not initialized (thus UNINIT) and the variable ar is dereferenced without checking for null (thus FORWARD_NULL).
Probably this code will work:
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
int fn1(int **ar)
{
int *a = NULL;
if (ar == NULL) {
fprintf(stderr, "Omg! you passed NULL as first argument to fn1 function. What to do now? Break the program flow for sure - return or abort() or exit() !");
abort();
return EXIT_FAILURE;
}
a = *ar;
return EXIT_SUCCESS;
}
edited Jan 10 at 16:47
Paul Floyd
2,70811830
answered Nov 13 '18 at 12:23
Kamil CukKamil Cuk
10.3k1527
edited Jan 10 at 16:47
Paul Floyd
2,70811830
edited Jan 10 at 16:47
Paul Floyd
2,70811830
edited Jan 10 at 16:47
Paul Floyd
2,70811830
2,70811830
answered Nov 13 '18 at 12:23
Kamil CukKamil Cuk
10.3k1527
answered Nov 13 '18 at 12:23
Kamil CukKamil Cuk
10.3k1527
answered Nov 13 '18 at 12:23
Kamil CukKamil Cuk
10.3k1527
10.3k1527
Thanks a lot. Trying it out. Once it is going to work, will update this as answer.
– Preethi
Nov 13 '18 at 13:07
I did this:int fn1(int **ar) { int *a = NULL; /* throws forward null, when NULL is removed, coverity throws unint errors. */ if (ar == NULL) { return 1;} a = *ar; }My coverity error still exists. @kamil
– Preethi
Nov 13 '18 at 13:24
add a comment |
Thanks a lot. Trying it out. Once it is going to work, will update this as answer.
– Preethi
Nov 13 '18 at 13:07
I did this:int fn1(int **ar) { int *a = NULL; /* throws forward null, when NULL is removed, coverity throws unint errors. */ if (ar == NULL) { return 1;} a = *ar; }My coverity error still exists. @kamil
– Preethi
Nov 13 '18 at 13:24
Thanks a lot. Trying it out. Once it is going to work, will update this as answer.
– Preethi
Nov 13 '18 at 13:07
Thanks a lot. Trying it out. Once it is going to work, will update this as answer.
– Preethi
Nov 13 '18 at 13:07
I did this:
int fn1(int **ar) { int *a = NULL; /* throws forward null, when NULL is removed, coverity throws unint errors. */ if (ar == NULL) { return 1;} a = *ar; } My coverity error still exists. @kamil– Preethi
Nov 13 '18 at 13:24
I did this:
int fn1(int **ar) { int *a = NULL; /* throws forward null, when NULL is removed, coverity throws unint errors. */ if (ar == NULL) { return 1;} a = *ar; } My coverity error still exists. @kamil– Preethi
Nov 13 '18 at 13:24
add a comment |
0
This helps easily:
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
strct1
{
int a;
int b;
char c;
};
int fn1()
{
strct1 *pvarA = NULL;
strct1 varA;
MEMSET(&varA, 0, sizeof (strct1));
pvarA = &varA;
if (fn2(&pvarA) != 0) // derefering NULL pointer error.
{
return 1;
}
/* some code */
}
int fn2(strct1 **pvarA)
{
/* some code */
*pvarA = varA;
/* some code */
return 0;
}
answered Jan 24 at 14:53
PreethiPreethi
67211
add a comment |
0
This helps easily:
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
strct1
{
int a;
int b;
char c;
};
int fn1()
{
strct1 *pvarA = NULL;
strct1 varA;
MEMSET(&varA, 0, sizeof (strct1));
pvarA = &varA;
if (fn2(&pvarA) != 0) // derefering NULL pointer error.
{
return 1;
}
/* some code */
}
int fn2(strct1 **pvarA)
{
/* some code */
*pvarA = varA;
/* some code */
return 0;
}
answered Jan 24 at 14:53
PreethiPreethi
67211
add a comment |
0
0
0
This helps easily:
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
strct1
{
int a;
int b;
char c;
};
int fn1()
{
strct1 *pvarA = NULL;
strct1 varA;
MEMSET(&varA, 0, sizeof (strct1));
pvarA = &varA;
if (fn2(&pvarA) != 0) // derefering NULL pointer error.
{
return 1;
}
/* some code */
}
int fn2(strct1 **pvarA)
{
/* some code */
*pvarA = varA;
/* some code */
return 0;
}
answered Jan 24 at 14:53
PreethiPreethi
67211
This helps easily:
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
strct1
{
int a;
int b;
char c;
};
int fn1()
{
strct1 *pvarA = NULL;
strct1 varA;
MEMSET(&varA, 0, sizeof (strct1));
pvarA = &varA;
if (fn2(&pvarA) != 0) // derefering NULL pointer error.
{
return 1;
}
/* some code */
}
int fn2(strct1 **pvarA)
{
/* some code */
*pvarA = varA;
/* some code */
return 0;
}
answered Jan 24 at 14:53
PreethiPreethi
67211
answered Jan 24 at 14:53
PreethiPreethi
67211
answered Jan 24 at 14:53
PreethiPreethi
67211
answered Jan 24 at 14:53
PreethiPreethi
67211
67211
add a comment |
add a comment |
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1
How exactly does this code makes sense to you? As for why it complains if you drop the NULL, we cannot say without a Minimal, Complete, and Verifiable example. It could also be a tool bug, but none can tell with what's given here.
– Lundin
Nov 13 '18 at 12:04
1
FORWARD_NULL implies that you're dereferencing the
NULL, but that's not what your code shows.– Sander De Dycker
Nov 13 '18 at 12:21
Your code doesn't match your question. Did you mean
*a = **ar?– Jabberwocky
Nov 13 '18 at 12:29
Nope. It is matching. @Jabberwocky I wanted to do
a = *ar. But in the lineint *a = NULL, getting coverity error as mentioned in the comments/* */– Preethi
Nov 13 '18 at 13:32