the Java one). ", 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". Search for vulnerabilities resulting from the violation of this rule on the CERT website. Calls to extension methods are not reported because they can still operate on null values. positive S2637 in SonarQube 6.7.1 LTS, Sonar false positive, "change condition so that it does not always evaluate to true. Im very new to sonar, is there a way to add methods to the whitelist? Dereferencing a null pointer is undefined behavior, typically abnormal program termination. However there is no portable way to verify that the pointer is valid, other than checking for null. At this point we define size as strlen(input_str) + 1. Batch split images vertically in half, sequentially numbering the output files, Recovering from a blunder I made while emailing a professor. Likewise, pointers to freed memory are not valid. 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. That's true. 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. In the meantime, Im locking this thread. Im having trouble understanding your problem. - the incident has nothing to do with me; can I use this this way? 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. Is there a single-word adjective for "having exceptionally strong moral principles"? I reordered that code example to do all the checks before allocations. Why does Mister Mxyzptlk need to have a weakness in the comics? On many platforms, dereferencing a null pointer results in abnormal program termination, but this is not required by the standard. , . Trying to understand how to get this basic Fourier Series. In order to fix this, just do the following: If you are absolutely sure that res.getBody() stays null and is also not modified by another thread, you could also use a //NOSONAR comment in order to suppress the warning. Doing so will cause a NullReferenceException to be thrown. It means this is illegal: T* p = nullptr; T& r = *p; // illegal NOTE: Please do not email us saying the above works on your particular version of your particular compiler. A null pointer in this position causes the read system call to fail with -EINVAL ("Invalid argument"). While the engine is in practice already able to explore code from other files if needed (relying solely on bytecode), we restrain this approach to a limited set of well-known methods from standard libraries, for which we know that behaviors are correctly produced. Finally my method is returning a response with value of restTemplate. SonarJava Version 5.9.2 (build 16552). Alternate Terms Relationships 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(). Rule squid:S2259 is based on a Symbolic Execution (SE) engine. assert(!invalid(p)); // or whatever, bool invalid(const void *p) { How can we let this pass? Carnegie Mellon University
rev2023.3.3.43278. I have a sonar alert on this call minRating.getRatgCaam(). At worst, it could expose debugging information that would be useful to an attacker or it could allow an How do you ensure that a red herring doesn't violate Chekhov's gun? This compliant solution ensures that the pointer returned by png_malloc() is not null. At worst, it could expose debugging information that would be useful to an attacker, or it could allow an attacker to bypass security measures. Some Interesting Facts: 1) void pointers cannot be dereferenced. But what exactly does it mean to "dereference a null pointer"? Unfortunately the problem is much more complex, and generally unsolvable within standard C. Consider the following example: There's no way f can check whether x points into valid memory or not. It also adds assertions to document that certain other pointers must not be null. When exploring such methods, the engine then deduces behaviors regarding null-checking (among other things). Batch split images vertically in half, sequentially numbering the output files, Difficulties with estimation of epsilon-delta limit proof, Minimising the environmental effects of my dyson brain. Depending on whether the pointer is valid (i.e. Void pointers cannot be dereferenced as any other pointer. And if there is no pointer_default declaration, then the default default is ref. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Dereferencing a null pointer results in undefined behavior. 4. Report False-positive / False-negative [LTS] The new SonarQube LTS is here: SONARQUBE 9.9 LTS, SonarQube - Null Pointer Dereference Issue. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. We can see that at obj.run(), obj can not be null, but is pointed out by Sonar. Privacy Policy, Detect issues in your GitHub, Azure DevOps Services, Bitbucket Cloud, GitLab repositories. The libpng library implements its own wrapper to malloc() that returns a null pointer on error or on being passed a 0-byte-length argument. Since SIZE_MAX represents the largest possible object, the largest possible string would then be SIZE_MAX-1 characters long (excluding '\0'). How handle the initialization of "responseDto" without "null" because is throwing the issue on sonar. At best, such an exception will cause abrupt program termination. Connect and share knowledge within a single location that is structured and easy to search. Software project. Perhaps this could be done with a special constraint that will notify the SE engine that we learned from a Debug.Assert call. Because null pointer dereferencing is UB, the if (!tun) check can be elided entirely by the optimizer (since the tun->sk implies that tun must be non-null). 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. If you preorder a special airline meal (e.g. 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. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. So let me be more precise in my wording: I assert that a platform whose memcpy() did anything besides copy zero bytes when given n=0 and valid src and dest pointers was not C-standards-compliant. (from res.getBody().getServiceResult() ). But passing 0 to memcpy() is not one of them. 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. Using platform-specific means (e.g. I suppose we can check that that is not null, but we cannot check that it is valid (in any portable way). Thanks for contributing an answer to Stack Overflow! Is it possible to rotate a window 90 degrees if it has the same length and width? NULL vs Uninitialized pointer - An uninitialized pointer stores an undefined value. Can I tell police to wait and call a lawyer when served with a search warrant? It does not point to any area of memory. Sonar is ok. It also uses the unsigned type size_t to pass the length parameter, ensuring that negative values are not passed to func(). Whoops, you're right. Asking for help, clarification, or responding to other answers. To learn more, see our tips on writing great answers. Are there tables of wastage rates for different fruit and veg? res.getBody() == null || res.getBody().getServiceResult() == null). Not the answer you're looking for? A bug can cause them never to be reassigned. I suggest that this topic needs to include calloc() and realloc() Refer to Linux man pages online for more enlightenment about malloc(), and friends. The Clang Static Analyzer already has a checker to find the null pointer dereference in code, however it is not sufficient for higher abstractions such as C++ smart pointers or optionals. The chunkdata pointer is later used as a destination argument in a call to memcpy(), resulting in user-defined data overwriting memory starting at address 0. 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. Put a new ResponseEntity is wrong because I won't know what will be the answer for the status of http. EXP34-C is a common consequence of ignoring function return values, but it is a distinct error, and can occur in other scenarios too. The final NCCE is actually more insidious than it seems at first. Im currently using SonarQube version 5.6.6. better way to handle this is to store the result of method invocation in a variable. . 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.) 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). vegan) just to try it, does this inconvenience the caterers and staff? 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. I would also guess that pointers that point to the one-past-the-end of an array are also invalid. In C, dereferencing a null pointer is undefined behavior. The article easily misleads the reader into believeing that ensuring pointer validity boils down to checking for pointer being not equal to NULL. it could allow an attacker to bypass security measures. 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 Do not dereference null pointers Created by Jeffrey Gennari, last modified by Jill Britton on Jan 18, 2023 Dereferencing a null pointer is undefined behavior. Please explain: Without this, we wont be able to help you. In the first compliant example it's useless to do allocation if the essential pointer user_data is NULL. To be precise, once length is changed to a size_t and cannot take negative values, it cannot have an invalid value. sometimes FP occurs. However, memory allocation > functions such as kstrdup() may fail and returns NULL. 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. C static code analysis: Null pointers should not be dereferenced C static code analysis Unique rules to find Bugs, Vulnerabilities, Security Hotspots, and Code Smells in your C code All rules 311 Vulnerability 13 Bug 74 Security Hotspot 18 Code Smell 206 Quick Fix 14 Tags "memset" should not be used to delete sensitive data Vulnerability 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. 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 you can declare a string t and then add characters to the string with a plus sign : t += 'a'; The code you are having issue with is just moving the pointer to the next character which the foreach is already doing. in above code, Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. You're in a company-managed project. Trying to understand how to get this basic Fourier Series. Avoid Returning null from Methods. Appropriate typecasting is necessary. It looks like a logic bug, which can cause a memory leaking. In the complaint version, I like to make source code checking a little quicker by putting parenthesizes around arguments to |= or &= as. Hello. Believing that dereferencing NULL shouldn't crash the system doesn't make it true. When a variable is declared as being a pointer to type void, it is known as a generic pointer. Thanks, David! Consider the following scenario: you are asked to create a Java class MetaDisplay that contains a static void printTable(String r) method. I suppose there is a question of "Is a pointer that points to 0 bytes valid?"
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