Iflengthhas the value1, the addition yields 0, and png_malloc() subsequently returns a null pointer, which is assigned to chunkdata. 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. Void pointers cannot be dereferenced as any other pointer. Phew, we're agreed here. static-code-analysis How can I check before my flight that the cloud separation requirements in VFR flight rules are met? C static code analysis: Null pointers should not be dereferenced Doing so will cause a NullReferenceException to be thrown. If the project is not compiled, and without sonar.java.binaries whether the white list takes effect? 9.7 Null pointers - Learn C++ - LearnCpp.com public boolean isNameEmpty() { return getName().length() == 0; // Noncompliant; the result of getName() could be null, but isn't null-checked } . 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! Did any DOS compatibility layers exist for any UNIX-like systems before DOS started to become outmoded? To be precise, once length is changed to a size_t and cannot take negative values, it cannot have an invalid value. Basically, yes. very old code or C code being worked into c++ may have functions that expect the user to delete the data. SonarQube Version 6.7.2 (build 37468) In multithreaded programs, null pointer dereferences can violate cache coherency policies and can cause resource leaks. Is there a proper earth ground point in this switch box? 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. sonar_etReines-CSDN Things go fine now. Doing so will cause a NullPointerException to be thrown. 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. The user_data pointer could be invalid in other ways, such as pointing to freed memory. How can I check before my flight that the cloud separation requirements in VFR flight rules are met? Optimizers are optimizing based on this latitude and have been for years. [4] When c_str is dereferenced in memcpy(), the program exhibits undefined behavior. ", 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". Clearly the standard enumerates 1 case of undefined behavior, but makes no special mention of n=0. The libpng library allows applications to read, create, and manipulate PNG (Portable Network Graphics) raster image files. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. }. I suppose there is a question of "Is a pointer that points to 0 bytes valid?" https://stackoverflow.com/questions/47534436/, https://stackoverflow.com/questions/47534436/, java - Jenkins groovy : Error: java. Java Specification Participation Agreement version in use: 2.0. PS: I also tried the code in android studio which uses Lint and got no warnings. LANG.MEM.NPDLANG.STRUCT.NTADLANG.STRUCT.UPD, Null pointer dereferenceNull test after dereferenceUnchecked parameter dereference, Can detect violations of this rule. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, how to handle Sonarlint java:S2259 (Null pointers should not be dereferenced), How Intuit democratizes AI development across teams through reusability. EXP34-C is a common consequence of ignoring function return values, but it is a distinct error, and can occur in other scenarios too. When B is null, The control reaches inside the main if block only when length of A is 1. Are there tables of wastage rates for different fruit and veg? Sonar is ok. Sonar can't determine that the helper method did the null validation. 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?) I've changed it to say null pointer instead of invalid pointer. Null pointer should not be dereferenced . Not the answer you're looking for? ncdu: What's going on with this second size column? Believing that dereferencing NULL shouldn't crash the system doesn't make it true. Aaron:I suspect we are talking past each other. So Bar might not be initialized but then the last line of your example should not be evaluated in this case. Can I tell police to wait and call a lawyer when served with a search warrant? To subscribe to this RSS feed, copy and paste this URL into your RSS reader. To create a custom null validation method declare an attribute with name ValidatedNotNullAttribute and mark the parameter that is Does Counterspell prevent from any further spells being cast on a given turn? What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? VB.NET static code analysis: Null pointers should not be dereferenced Consider the following scenario: you are asked to create a Java class MetaDisplay that contains a static void printTable(String r) method. This rule applies to all null pointers, regardless of which function returned them. Dereferencing a null pointer can lead to a denial of service. A NULL pointer can be dereferenced when signatures are being verified on PKCS7 signed or signedAndEnveloped data. Solution 1, it looks like, today's solution tomorrow's problem. To learn more, see our tips on writing great answers. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Whats the grammar of "For those whose stories they are"? Also, the term 'pointer' is bad (but maybe it comes from the FindBugs tool): Java doesn't have pointers, it has references. 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. the Java one). NULL vs Uninitialized pointer - An uninitialized pointer stores an undefined value. EXP34-C. Do not dereference null pointers - Confluence Pointer is so confusing : Stack with singly linked list in C - Stack A null pointer in this position causes the read system call to fail with -EINVAL ("Invalid argument"). Which ensures that the chunkdata pointer is valid, but makes no such check to the user_data pointer. () How can we prove that the supernatural or paranormal doesn't exist? (In contrast, the case of passing 0 bytes to malloc is addressed in C11.) SonarJava. Two null pointers will always be equal to each other. In order to fix this, just do the following: BodyType body=res.getBody (); if (body == null || body.getServiceResult () == null) { return; } You can then even reuse body after that. Unlike reference types, pointer types are not tracked by the default garbage . Reference vs dereference pointers in arguments C++/C It does not point to any area of memory. Yeah, I suspect once it's possible to allocate 2+gigs contiguously in amainstream install of a modern OS, we'll see a frenzy of new vulnerabilities come out. https://www.yammer.com/ http://feeds.feedburner.com/office/fmNx In my experience, there are reasons to check for a NULL pointer other than dereferencing it. // <------- reported violation: NullPointerException might be thrown as 'bar' is nullable here, https://jira.sonarsource.com/browse/SONARJAVA-1490, https://groups.google.com/d/msgid/sonarqube/4752a999-246e-42c2-bbdc-8a44a5564ce9%40googlegroups.com. Null pointers should not be dereferenced (#42) Issues - GitLab This sounds indeed like a bug in the flow when an exception is raised. The problem is that something like %*pbl which reads a bitmask, will save the pointer to the bitmask in the buffer. That's true. There are other problems with this code, as is noted in the rule. I have checked on multiple . 3.Null pointers should not be derefer enced/accessed. Using Kolmogorov complexity to measure difficulty of problems? The test was added to catch the possibly theoretical situation where the length of input_str was somehow the maximum size for size_t, and adding one to this size in the malloc expression (to allocated space for the trailing null byte) results in an integer overflow. sonarlint complains that I believe in this case, either expression would work. If you try to access any member variables or methods with that variable, you are trying to dereference it. Sonar is ok. Thank you for clarifying your assertion until I understood it properly. Unfortunately, its actual state also has some limitations, like the one you are hitting here. If you write [ref], then a null pointer is not allowed, but if you write [unique], then a null pointer is permitted. Thanks for contributing an answer to Stack Overflow! We seem to have a false positive for "Null pointers should not be dereferenced" - squid:S2259. 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. Is it plausible for constructed languages to be used to affect thought and control or mold people towards desired outcomes? How to fix int cannot be dereferenced? Explained by Sharing Culture Here is our source code: Sign in to download full-size image Not the answer you're looking for? On many platforms, dereferencing a null pointer results inabnormal program termination, but this is not required by the standard. 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). By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. sonarLint (3.2.) which version of SonarQube are you using? A null pointer stores a defined value, but one that is defined by the environment to not be a valid address for any member or object. Im very new to sonar, is there a way to add methods to the whitelist? 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. At this point we define size as strlen(input_str) + 1. It is generally accepted that zeroing a pointer is a good way to mark it as invalid and dereferencing an invalid pointer is a bug. 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. , NPE : null-, . in above code, Its purpose is to serve as a special value for a pointer that could indicate a special condition in your program. If not, this might be a bug. Finally, there is the matter of the compliant solution. Can I tell police to wait and call a lawyer when served with a search warrant? 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>. This solution also ensures that theuser_data pointer is not null. Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2. rev2023.3.3.43278. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide.