uninitialized reference-type class members. Is it possible to rotate a window 90 degrees if it has the same length and width? A reference to Nothing should never be dereferenced/accessed. A reference to null should never be dereferenced/accessed. At best, such an exception will cause abrupt program termination. C# static code analysis: Null pointers should not be dereferenced Products In-IDE IDE extension that lets you fix coding issues before they exist! I already tried to put ResponseEntity responseDto inside my try clause assigning and returning the respective value but its mandatory to return something out the try/catch. Obviously the value of that pointer could have changed since the . You can use Optional instead. Solution 1, it looks like, today's solution tomorrow's problem. Please direct comments on this JSR to the Spec Lead (s) Team. The approximation of the try catch flow is such that we consider an exception can be thrown just after the curly brace of the try. This compliant solution eliminates the null pointer deference by initializing sk to tun->sk following the null pointer check. However, memory allocation > functions such as kstrdup() may fail and returns NULL. 0 is a valid value as far as memcpy() is concerned, and malloc() has special language concerning malloc(0). Just a few words about the rule now. Shouldn't the function check all pointers before dereferencing them or passing them to another function? This is a feature that we are currently heavily working on to be able to switch off such kind of false positives. In this noncompliant code example, input_str is copied into dynamically allocated memory referenced by c_str. Share Improve this answer Follow answered Oct 5, 2017 at 16:27 Issues Components. ), Does not guess that return values from malloc(), strchr(), etc., can be NULL (The return value from malloc() is NULL only if there is OOMo and the dev might not care to handle that. to 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. Now (sonarqube java analyzer version 4.3.0.7717) it's supported and works fine. 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. We really appreciate your help. Software project. ", Eclipse - Sonar S2629 possible false positive with new String, SonarQube null pointers should not be dereferenced on try/catch, getTextContent() through "Null pointers should not be dereferenced". Are there tables of wastage rates for different fruit and veg? best, such an exception will cause abrupt program termination. Check whether a String is not Null and not Empty. The n=0 is a mildly interesting edge case: Clearly a pointer that points to at least one valid byte could be used as the src or dest pointer to a call to memcpy(, 0). To be precise, once length is changed to a size_t and cannot take negative values, it cannot have an invalid value. Does a summoned creature play immediately after being summoned by a ready action? The final NCCE is actually more insidious than it seems at first. Trying to understand how to get this basic Fourier Series. Find centralized, trusted content and collaborate around the technologies you use most. Reports. You're in a company-managed project. And if there is no pointer_default declaration, then the default default is ref. How do I align things in the following tabular environment? , . I have a sonar alert on this call minRating.getRatgCaam(). To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Find centralized, trusted content and collaborate around the technologies you use most. The solution that I recommend is not work with null returns or variables on Java, try to avoid it. > Further, if kstrdup() returns NULL, we should return ERR_PTR(-ENOMEM) to > the caller site. My below code where I'm calling a stored procedure is giving a null pointer exception. 3.7. sonarlint, sonarLint (3.2.) By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. NullPointerException is thrown when program attempts to use an object reference that has the null value. )}"); Reports. We. A pointer to null (the 0 memory address) should never be dereferenced/accessed. This sounds indeed like a bug in the flow when an exception is raised. In case the hash algorithm used for the signature is known to the OpenSSL library but the implementation of the hash algorithm is not available the digest initialization will fail. How can we prove that the supernatural or paranormal doesn't exist? public boolean isNameEmpty() { return getName().length() == 0; // Noncompliant; the result of getName() could be null, but isn't null-checked } . How to deal with "java.lang.OutOfMemoryError: Java heap space" error? Since you cannot have a variable of type void, the pointer will not point to any data and therefore cannot be dereferenced. To create a custom null validation method declare an attribute with name ValidatedNotNullAttribute and mark the parameter that is "After the incident", I started to be more careful not to trip over things. When I scan with sonar-lint in idea, it seams white list is useful, but when use sonar-scanner, always FP, org.springframework.util.CollectionUtils#isEmpty Haiku is a free and open-source operating system for PC designed to be binary compatible with the BeOS operating system and embodying the basic ideas of BeOS. I would also guess that pointers that point to the one-past-the-end of an array are also invalid. Currently I'm working with SonarQube solving issues but I'm facing a trouble to how handle null pointers that shouldn't be dereferenced. res.getBody() == null || res.getBody().getServiceResult() == null). Thank you for clarifying your assertion until I understood it properly. Null pointer should not be dereferenced , , RemoteContext new ExceptionType() RemoteContext , SonarLintJava (), java - sonarLint "Null pointers should not be dereferenced (squid:S2259)"Stack Overflow Its purpose is to serve as a special value for a pointer that could indicate a special condition in your program. How handle the initialization of "responseDto" without "null" because is throwing the issue on sonar. Correct; a null pointer is not a valid pointer for the C library functions. specifies the length of the array for a function. Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2, Sonar: Null pointers should not be dereferenced, Why should Java 8's Optional not be used in arguments, Sonar alert : "private" methods that don't access instance data should be "static", sonarLint complains "Null pointers should not be dereferenced (squid:S2259)" despite that possibility being handled, Java: (false?) parsing /proc/self/maps under linux) one might find out whether the pointer points into mapped memory, but this is still not a guarantee of validity because it is very coarse-grained see again the above example. SonarJava. A pointer is simply a variable that contains a memory address. Note that it doesn't know how to check for non-heap, non-stack. At Do "superinfinite" sets exist? If the project is not compiled, and without sonar.java.binaries whether the white list takes effect? . This topic was automatically closed 7 days after the last reply. sonarLint (3.2.) This issues is displayed by SonarQube. We resolved it by adding our tools path in the white list, and repackaging it. SonarJava Version 5.9.2 (build 16552). assert(!invalid(p)); // or whatever, bool invalid(const void *p) { Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, It is a false positive, but it might be a good idea not to do the, Sonar false-positive on rule: Null pointers should not be dereferenced, How Intuit democratizes AI development across teams through reusability. This is indeed a false positive because, at time of writing, the sonarqube java analyzer (version 4.2.1 at time of writing) does not support cross procedural analysis and so it is not able to determine that indeed, for the condition to be true, the value of minRating has to be non null. A nonnegative return value represents the number of bytes successfully read (the return value is a "signed size" type, usually the native integer type for the target platform). Can you please start a new thread and be more explicit about the issue you are observing. Find centralized, trusted content and collaborate around the technologies you use most. Whats the grammar of "For those whose stories they are"? Appropriate typecasting is necessary. A null pointer in this position causes the read system call to fail with -EINVAL ("Invalid argument"). 11 Sep, 2006. The null pointer check for writing or dereferencing should be a compiler flag or library setting. It's even called out explicitly in C17 7.24.1p2: Where an argument declared as size_t n specifies the length of the array for a function, n can have the value zero on a call to that function. Hi Andreas, Thanks for the feedback. So, this code should address the Sonar problem: You can also eliminate the null check using Optional>, like: Even I don't recommend this, you can just check the null responseDto without any use of Optional: Thanks for contributing an answer to Stack Overflow! By explicitly teaching the C++ standard class behaviors we can make the Analyzer to find more bugs related to modern C++ code. Is the God of a monotheism necessarily omnipotent? I suppose we can check that that is not null, but we cannot check that it is valid (in any portable way). Aaron:I suspect we are talking past each other. But no where in that particular idiom would a NULL pointer necessarily be deferenced. When length is zero, it is probably unusable condition for this function. In the simplest case, this function just returns the result of calling kmalloc. Write a semantic patch to nd cases where the result of calling kmalloc is dereferenced with no previous NULL pointer test. Thanks for contributing an answer to Stack Overflow! In the code, we check the not nullity with java.util.Objects.nonNull(). Doing so will cause a NullReferenceException to be thrown. Good question! Could I capture, and I would be able to glean much security information from the dump? Revert Update S2259: "Null pointer dereference" CFG should ignore expressions in Debug.Assert #397 Introduce means to not raise "Expression always true/false" on values that were checked with Debug.Assert. The expected result here is solve the issue with sonarqube. In multithreaded programs, null pointer dereferences can violate cache coherency policies and can cause resource leaks. Accessing or modifying a null object's field. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. I'd guess null pointers are not valid, even though they point to 0 bytes. Search for vulnerabilities resulting from the violation of this rule on the CERT website. 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 . You need to benchmark. 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. Sonar detects that res.getBody() can be null when you do the check res.getBody()==null. When c_str is dereferenced in memcpy(), the program exhibits undefined behavior. At worst, it could expose debugging information that would be useful to an attacker or it could allow an ii. I suggest that this topic needs to include calloc() and realloc() Refer to Linux man pages online for more enlightenment about malloc(), and friends. JCP version in use: 2.6. }. Im currently using SonarQube version 5.6.6. better way to handle this is to store the result of method invocation in a variable. I added a comment to explain that SIZE_MAX is the limit of size_t. This code also violates ERR33-C. Detect and handle standard library errors. To learn more, see our tips on writing great answers. That's true. Put a new ResponseEntity is wrong because I won't know what will be the answer for the status of http. This sounds indeed like a bug in the flow when an exception is raised. Using Kolmogorov complexity to measure difficulty of problems? Unless explicitly stated otherwise in the description of a particular function in this subclause, pointer arguments on such a call shall still have valid values, as described in 7.1.4. Is there a single-word adjective for "having exceptionally strong moral principles"? To subscribe to this RSS feed, copy and paste this URL into your RSS reader. The method isNR (minRating) is a helper method that validate among other things, if the object minRating is null public boolean isNR (AgencyRating rating) { return rating == null || isNR (rating.getRatgCaam ()); } When I added the not null validation as sonar suggest. See the "Null pointer checks may be optimized away more aggressively" section inhttps://gcc.gnu.org/gcc-4.9/porting_to.htmlas an example with one common implementation. One could argue that all code examples would be redundant with the first pair. How to tell which packages are held back due to phased updates. I am a student implementing stack with singly linked list using C, following a book called Fundamentals of Data Structures in C.. 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. This latter use of pointers is a combined boolean/satellite: the pointer being non-null indicates "I have this sister object", and it provides that object. Is there a solution to add special characters from software and how to do it, Acidity of alcohols and basicity of amines. When and how should I use a ThreadLocal variable? It also uses the unsigned type size_t to pass the length parameter, ensuring that negative values are not passed to func(). Is null check needed before calling instanceof? Best to cite C11 s7.24.2.1 here: The memcpy function copies n characters from the object pointed to by s2 into the object pointed to by s1. isEmpty(Collection collection) Some Interesting Facts: 1) void pointers cannot be dereferenced. In the first compliant example it's useless to do allocation if the essential pointer user_data is NULL. That interpretation of the standard is not supported universally. Why is there a voltage on my HDMI and coaxial cables? Powered by Discourse, best viewed with JavaScript enabled. Privacy Policy, Detect issues in your GitHub, Azure DevOps Services, Bitbucket Cloud, GitLab repositories. Setup is effortless and analysis is automatic for most languages, Fast, accurate analysis; enterprise scalability. I suppose there is a question of "Is a pointer that points to 0 bytes valid?" Making statements based on opinion; back them up with references or personal experience. 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. . That is only true if possibleNumbers contains no element.. BTW: none of these warnings are shown by . Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. You're in a company-managed project. Java Specification Participation Agreement version in use: 2.0. 2008-2023 SonarSource S.A., Switzerland. But when length of A is 1, the control never reaches the else block. A value is checked here to see whether it is null, but this value can't be null because it was previously dereferenced and if it were null a null pointer exception would have occurred at the earlier dereference. (C11, S7.24.2.1). Should trycatch go inside or outside a loop? How can we prove that the supernatural or paranormal doesn't exist?