Find centralized, trusted content and collaborate around the technologies you use most. the Java one). rev2023.3.3.43278. When I added the not null validation as sonar suggest. We can get a reference to point to null in the following ways: "uninitialized" reference type variables variables which are initialized with nulls and are assigned their real value afterward. Asking for help, clarification, or responding to other answers. Ticket opened : Thanks a lot for the minimalized reproducer ! I would also guess that pointers that point to the one-past-the-end of an array are also invalid. At worst, it could expose debugging information that would be useful to an attacker, or it could allow an attacker to . Just because something is a pointer does not mean you should call delete . - the incident has nothing to do with me; can I use this this way? So the SIZE_MAX check was unnecessary. IDE extension that lets you fix coding issues before they exist! If the pointer is not NULL, see if the assignment occurs only in a branch of a conditional statement.Investigate when that branch does not execute. 1 Answer Sorted by: 2 Your code needs to do something about the possible NullPointerException when some exception is caught, because in this scenario the responseDto will be null. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. https://stackoverflow.com/questions/47534436/, https://stackoverflow.com/questions/47534436/, java - Jenkins groovy : Error: java. Such long getter chains can also be replaced with Optional + map + ifPresent lambda style. To learn more, see our tips on writing great answers. Unlike reference types, pointer types are not tracked by the default garbage . It could be non-null the first time but not the second time, sonar does not know this. Is a PhD visitor considered as a visiting scholar? Is there a solution to add special characters from software and how to do it, Acidity of alcohols and basicity of amines. Is there a proper earth ground point in this switch box? Automated Detection Null pointer dereferences can happen in path-dependent ways. java You can use Optional instead. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, SonarQube null pointers should not be dereferenced on try/catch, How Intuit democratizes AI development across teams through reusability. I've changed it to say null pointer instead of invalid pointer. What are the effects of exceptions on performance in Java? The problem is, I hope this code's result to be <5,3> and <9,6> BUT the console only shows me <5,3> and <9,3>. Thank you for clarifying your assertion until I understood it properly.
9.7 Null pointers - Learn C++ - LearnCpp.com sonar-java. sonarLint (3.2.) Passing a null pointer tomemcpy() would produce undefined behavior, even if the number of bytes to copy were 0. We can see that at obj.run(), obj can not be null, but is pointed out by Sonar. At this point we define size as strlen(input_str) + 1. 3.Null pointers should not be derefer enced/accessed.
(C11, S7.24.2.1). If malloc() fails, it returns a null pointer that is assigned to c_str. How do I align things in the following tabular environment? This engine is validating execution paths and checking for non-null values or null-check along the way, exploring all the possibilities. Powered by Discourse, best viewed with JavaScript enabled. In the case of the ARM and XScale architectures, the 0x0 address is mapped in memory and serves as the exception vector table; consequently, dereferencing 0x0 did not cause an abnormal program termination. A null pointer in this position causes the read system call to fail with -EINVAL ("Invalid argument"). Appropriate typecasting is necessary. Is there a proper earth ground point in this switch box? that we haven't considered here: I'd guess null pointers are not valid, even though they point to 0 bytes. attacker to bypass security measures. When B is null, The control reaches inside the main if block only when length of A is 1.
1. Introduction - Understanding and Using C Pointers [Book] The nature of simulating nature: A Q&A with IBM Quantum researcher Dr. Jamie We've added a "Necessary cookies only" option to the cookie consent popup. Now (sonarqube java analyzer version 4.3.0.7717) it's supported and works fine. Is the God of a monotheism necessarily omnipotent? Software Engineering Institute
In C# and Java, all reference types can point to null. Instead use String.valueOf (object). I was fixing some issues gathered by SonarQube when I stumbled upon the following issue: SonarQube violation: Possible null pointer dereference in ___ due to return value of called method, This error was found in the following code: else if (foo.list().length > 0) { }, I attempted to resolve this by rewriting as: else if (null != foo.list() && foo.list().length > 0) { }, foo is an instance of the File class in Java, and is directly instantiated through new File(). If you write [ref], then a null pointer is not allowed, but if you write [unique], then a null pointer is permitted. ssize_t (*aio_read)(struct kiocb *, char __user *, size_t . That makes sense. When B is null, The control reaches inside the main if block only when length of A is 1. Why are physically impossible and logically impossible concepts considered separate in terms of probability? In this noncompliant code example, input_str is copied into dynamically allocated memory referenced by c_str. I think that checking for user_data being NULL would be an improvement to the CS so long as there is an explicit mention that user_data being NULL is invalid even if length == 0. Is there a single-word adjective for "having exceptionally strong moral principles"? There can be a null pointer type for each pointer type, such as a pointer to a character or a pointer to an integer, although this is . extern char _etext; (in the meantime, in case of any other false-positive suspicion, make sure to check those latest versions as bunch of improvements are regularly released). This topic was automatically closed 7 days after the last reply. To learn more, see our tips on writing great answers. We resolved it by adding our tools path in the white list, and repackaging it.
EXP01-J. Do not use a null in a case where an object is required The standard will simply copy 0 byteswhich is essentially a no-op. When c_str is dereferenced in memcpy(), the program exhibits undefined behavior. Note that 7.1.4 explicitly states that a null pointer is not a valid pointer argument. Key here (explains table format and definitions), EXP34-C = Union( CWE-690, list) where list =. To learn more, see our tips on writing great answers. Doing so will cause a NullReferenceException to be thrown. SonarLint IntelliJ 4.0.0.2916 Java Rule 'Null pointers should not be dereferenced' I'm getting this fault in the next code when obj can't be null in any scenario.
That interpretation of the standard is not supported universally. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. IMHO, the rule title should be changed to something less general. In the meantime, Im locking this thread.
[RSPEC-2259] - Jira C# static code analysis: Null pointers should not be dereferenced That is, sets equivalent to a proper subset via an all-structure-preserving bijection. See C17 7.1.4p1, which says, in part: Each of the following statements applies unless explicitly stated otherwise in the detailed descriptions that follow: If an argument to a function has an invalid value (such as a value outside the domain of the function, or a pointer outside the address space of the program, or a null pointer, or a pointerto non-modifiable storage when the corresponding parameter is not const-qualified) or a type (after default argument promotion) not expected by a function with a variable number of arguments, the behavior is undefined. vegan) just to try it, does this inconvenience the caterers and staff? If you call connect() function, it better do the connection, but failing simply because some ptr is NULL is not good behaviour -- failures should .
Why void pointer cannot be dereferenced? Explained by Sharing Culture Thanks for contributing an answer to Stack Overflow! How to use Slater Type Orbitals as a basis functions in matrix method correctly? Using platform-specific means (e.g. 412-268-5800, If an argument to a function has an invalid value (such as a value outside the domain of the function, or a pointer outside the address space of the program, or a null pointer, or a pointer. minimal code sample to reproduce (with analysis parameter, and potential instructions to compile). The 2nd NCCE/CS pair seems redundant with the first NCCE/CS pair. Why does the second compliant example permit using possibly-null pointers? Thus we should check > this kstrdup() operation. I think "res.getBody() == null" checks null first so it should go to return line, not reach to next if condition. The solution that I recommend is not work with null returns or variables on Java, try to avoid it. This compliant solution ensures that the pointer returned by png_malloc() is not null. Hi @Michael!
When should pointers be checked for NULL in C? positive S2637 in SonarQube 6.7.1 LTS, SonarQube for MSBuild not reporting quality issues, getTextContent() through "Null pointers should not be dereferenced". Find centralized, trusted content and collaborate around the technologies you use most. At worst, it could expose debugging information that would be useful to an attacker, or it could allow an attacker to bypass security measures. The result of calling such a helper function should be . Privacy Policy, Detect issues in your GitHub, Azure DevOps Services, Bitbucket Cloud, GitLab repositories. Because null pointer dereferencing is undefined behavior, the compiler (GCC in this case) can optimize away the if (!tun) check because it is performed after tun->sk is accessed, implying that tun is non-null.
Callable statement giving Null Pointer Exception - Oracle Forums 3.7. I believe that dereferencing NULL should not crash the system, should not allow a write to a NULL pointer area, but should always set errno, If I am a hacker, could I trap a null failure that would force a memory dump. False-positives are pointed out in other SO posts (1 & 2), where nulls are involved across functions and procedures. Is there a single-word adjective for "having exceptionally strong moral principles"? There is no legitimate reason to dereference a null pointer unless you on a rare system that maps page zero (or you intend your program to crash). Dereferencing > this null pointer may cause the kernel go wrong. In layman's terms, a null pointer is a pointer to an address in the memory space that does not have a meaningful value and cannot be referenced by the calling program, for whatever reason. I believe in this case, either expression would work. One could argue that all code examples would be redundant with the first pair. But the problem also exists in the compliant version, so I'm not so sure that it's really compliant. This is a matter of style, and also following code walkthrough. This sounds indeed like a bug in the flow when an exception is raised. PS: I also tried the code in android studio which uses Lint and got no warnings. The issue of passing n=0 to memcpy() is distinct from null or invalid pointers. Could I capture, and I would be able to glean much security information from the dump? ii. The null concept refers to the idea that a pointer can hold a special value that is not equal to another pointer.
Null Dereference | OWASP Foundation After that, you call res.getBody() again. This compliant solution ensures that both input_str andthe pointer returned by malloc() are not null: This noncompliant code example is from a version of drivers/net/tun.c and affects Linux kernel 2.6.30 [Goodin 2009]: The sk pointer is initialized to tun->sk before checking if tun is a null pointer. Thanks, David! Thanks for contributing an answer to Stack Overflow! "After the incident", I started to be more careful not to trip over things.