null pointers should not be dereferenced

When B is null, The control reaches inside the main if block only when length of A is 1. The user_data pointer could be invalid in other ways, such as pointing to freed memory. Key here (explains table format and definitions), EXP34-C = Union( CWE-690, list) where list =. All content is copyright protected. That interpretation of the standard is not supported universally. Sonar is ok. What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? Since you cannot have a variable of type void, the pointer will not point to any data and therefore cannot be dereferenced. Privacy Policy, Detect issues in your GitHub, Azure DevOps Services, Bitbucket Cloud, GitLab repositories. The purpose of a NULL pointer is not to cause a processor exception when it is dereferenced (although that is nice to have for debugging.) How do I align things in the following tabular environment? Report False-positive / False-negative [LTS] The new SonarQube LTS is here: SONARQUBE 9.9 LTS, S2259: Null pointers should not be dereferenced, find the list of whitelisted methods here, Rule java:S2259: False-positive NullPointerException bug logged when variable is null-checked by an imported method, What is the issue you are observing, in details, What version of SonarSource products you are using, as well as the version of SonarJava. Description: This JSR will work to develop standard annotations (such as @NonNull) that can be applied to Java programs to assist tools that detect software defects. isEmpty(Map map) 11 Sep, 2006. 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. Small typo nit: "such as if i t pointed to freed memory" meant to say "if it" instead (removing whitespace). Unfortunately, its actual state also has some limitations, like the one you are hitting here. Is there a single-word adjective for "having exceptionally strong moral principles"? I feel my situation is not as complicated. Powered by Discourse, best viewed with JavaScript enabled. We resolved it by adding our tools path in the white list, and repackaging it. When I added the not null validation as sonar suggest. To learn more, see our tips on writing great answers. Your assertion is not backed by the wording in the standard, nor by common implementer understanding. 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. These can be: Invoking a method from a null object. Privacy Policy, Detect issues in your GitHub, Azure DevOps Services, Bitbucket Cloud, GitLab repositories. Possible fix: Assign a valid address to the pointer in all branches of the conditional statement.. Pointer can point to dynamically allocated memory. ), 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. NullPointerException is thrown when program attempts to use an object reference that has the null value. But even with this, the concerned object it tagged as a possible NullPointerException problem. How can I check before my flight that the cloud separation requirements in VFR flight rules are met? 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>. Powered by Discourse, best viewed with JavaScript enabled. 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! 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. 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. When B is null, The control reaches inside the main if block only when length of A is 1. Doing so will cause a NullReferenceException to be thrown. SONAR, SONARSOURCE, SONARLINT, SONARQUBE and SONARCLOUD are trademarks of SonarSource S.A. All other trademarks and copyrights are the property of their respective owners. Im currently using SonarQube version 5.6.6. better way to handle this is to store the result of method invocation in a variable. Asking for help, clarification, or responding to other answers. SonarQube null pointers should not be dereferenced on try/catch, Sonarcube :Null pointers should not be dereferenced, How do you get out of a corner when plotting yourself into a corner. . So Bar might not be initialized but then the last line of your example should not be evaluated in this case. This compliant solution ensures that the pointer returned by png_malloc() is not null. Appropriate typecasting is necessary. public boolean isNameEmpty() { return getName().length() == 0; // Noncompliant; the result of getName() could be null, but isn't null-checked } . 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 Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. I say "theoretical" because I have not successfully produced strings of this length in testing. The null pointer check for writing or dereferencing should be a compiler flag or library setting. Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2. 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. A NULL pointer can be dereferenced when signatures are being verified on PKCS7 signed or signedAndEnveloped data. Note that it doesn't know how to check for non-heap, non-stack. It does not point to any area of memory. At best, such an exception will cause abrupt program termination. 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. 1 Null pointers should not be dereferenced @CheckForNull String getName(){.} The SonarJava SE engine is however, by default, not configured to explore methods declared in other files (in your case, your utility class CheckUtils). That is only true if possibleNumbers contains no element.. BTW: none of these warnings are shown by . 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. Do "superinfinite" sets exist? Whats the grammar of "For those whose stories they are"? Its purpose is to serve as a special value for a pointer that could indicate a special condition in your program. Is the God of a monotheism necessarily omnipotent? Can I tell police to wait and call a lawyer when served with a search warrant? Pittsburgh, PA 15213-2612 Seems the analizer don't recognice the logic with the funcional object Optional. Essentially, this code and the previous dereference disagree as to whether this value is allowed to be null. If not, this might be a bug. Not the answer you're looking for? I suppose we can check that that is not null, but we cannot check that it is valid (in any portable way). By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. 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. Clearly the standard enumerates 1 case of undefined behavior, but makes no special mention of n=0. A common memory-leak idiom, is reallocating storage and assigning its address to a pointer that already points to allocated storage. It is useful to have a function with portable interface but platform-dependent implementation: extern bool invalid(const void *); What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? ROSE does not handle cases where an allocation is assigned to an lvalue that is not a variable (such as a struct member or C++ function call returning a reference), Finds instances where a pointer is checked against NULL and then later dereferenced, Identifies functions that can return a null pointer but are not checked, Identifies code that dereferences a pointer and then checks the pointer against NULL, Can find the instances where NULL is explicitly dereferenced or a pointer is checked againstNULL but then dereferenced anyway. 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. What does "Could not find or load main class" mean? In my experience, there are reasons to check for a NULL pointer other than dereferencing it. Thank you for clarifying your assertion until I understood it properly. All rights are expressly reserved. I would therefore assert that a platform whose memcpy() did anything besides a no-op when given n=0 and valid source/destination pointers was not C-standards-compliant. At best, such an exception will cause abrupt program termination. And if there is no pointer_default declaration, then the default default is ref. ncdu: What's going on with this second size column? sometimes FP occurs. Discover SonarLint SaaS Setup is effortless and analysis is automatic for most languages Discover SonarCloud Self-Hosted Fast, accurate analysis; enterprise scalability Discover SonarQube Secrets ABAP After that, you call res.getBody() again. To create a custom null validation method declare an attribute with name ValidatedNotNullAttribute and mark the parameter that is Making statements based on opinion; back them up with references or personal experience. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. There are other problems with this code, as is noted in the rule. context.RaiseException , (/) This sounds indeed like a bug in the flow when an exception is raised. You can compare a pointer with NULL to test for the special condition. 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. minimal code sample to reproduce (with analysis parameter, and potential instructions to compile). Phew, we're agreed here. 0 is certainly within the 'domain of the function' (a phrase defined by mathematics but not by C11), as copying 0 bytes is well-understood (although silly). Using Kolmogorov complexity to measure difficulty of problems? Which ensures that the chunkdata pointer is valid, but makes no such check to the user_data pointer. Doing so will at best cause abrupt program termination, without the If you write [ref], then a null pointer is not allowed, but if you write [unique], then a null pointer is permitted. To learn more, see our tips on writing great answers. The 4gig boundary will probably be important too with unsigned int in LP64, but since size_t will be 64-bit, there will have to be some truncation that compilers will be able to warn on. I'd guess WG14 has considered these questions, but I haven't until now :). The 2nd NCCE/CS pair seems redundant with the first NCCE/CS pair. How can we prove that the supernatural or paranormal doesn't exist? If you preorder a special airline meal (e.g. Here is our source code: Sign in to download full-size image In the first compliant example it's useless to do allocation if the essential pointer user_data is NULL. Should trycatch go inside or outside a loop? This issues is displayed by SonarQube.