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 4500 Fifth Avenue isEmpty(Collection collection) 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). Are there tables of wastage rates for different fruit and veg? It could be non-null the first time but not the second time, sonar does not know this. . 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. As for copy vs pointer/reference - it depends. Thank you for clarifying your assertion until I understood it properly. 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 A null pointer in this position causes the read system call to fail with -EINVAL ("Invalid argument"). Connect and share knowledge within a single location that is structured and easy to search. Connect and share knowledge within a single location that is structured and easy to search. [4] When B is null, The control reaches inside the main if block only when length of A is 1. Mutually exclusive execution using std::atomic? Hello. which version of SonarQube are you using? Aaron:I suspect we are talking past each other. Thanks for contributing an answer to Stack Overflow! https://www.yammer.com/ http://feeds.feedburner.com/office/fmNx I would also guess that pointers that point to the one-past-the-end of an array are also invalid. null(java.lang.NullPointerException) . This code also violates ERR33-C. Detect and handle standard library errors. So the SIZE_MAX check was unnecessary. Can you please start a new thread and be more explicit about the issue you are observing. 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. The value 0 for the number of bytes to copy is not what causes the UB, it's the null pointer value which triggers it. In Java, a special null value can be assigned to an object reference. HTTP request redirections should not be open to forging attacks Deserialization should not be vulnerable to injection attacks Endpoints should not be vulnerable to reflected cross-site scripting (XSS) attacks "CoSetProxyBlanket" and "CoInitializeSecurity" should not be used Database queries should not be vulnerable to injection attacks 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. In C# and Java, all reference types can point to null. Is there a proper earth ground point in this switch box? java Is null check needed before calling instanceof? So Bar might not be initialized but then the last line of your example should not be evaluated in this case. The standard will simply copy 0 byteswhich is essentially a no-op. So Bar might not be initialized but then the last line of your example should not be evaluated in this case. 2008-2023 SonarSource S.A., Switzerland. My below code where I'm calling a stored procedure is giving a null pointer exception. Write a semantic patch to nd cases where the result of calling kmalloc is dereferenced with no previous NULL pointer test. 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 . To learn more, see our tips on writing great answers. I have a sonar alert on this call minRating.getRatgCaam(). Dereferencing a null pointer results in undefined behavior. Thanks for the feedback. This sounds indeed like a bug in the flow when an exception is raised. . Find centralized, trusted content and collaborate around the technologies you use most. To be precise, once length is changed to a size_t and cannot take negative values, it cannot have an invalid value. Unlike reference types, pointer types are not tracked by the default garbage . 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. Trying to understand how to get this basic Fourier Series. 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. What are the effects of exceptions on performance in Java? ncdu: What's going on with this second size column? A non-null but invalid pointer passed to memcpy() can indeed cause undefined behavior, but that is not the issue in the noncompliant codethe pointer will either be valid or null. How do you ensure that a red herring doesn't violate Chekhov's gun? If you preorder a special airline meal (e.g. Which version of SonarJava plugin do you have? SonarQube Version 6.7.2 (build 37468) The above check can't hurt, as I guess you could have a system with a 32-bit size_t that had a ton of memory and had some crazy banking/selector scheme with pointers. IMHO, the rule title should be changed to something less general. ii. Now, you can find the list of whitelisted methods here. (/). Currently I'm working with SonarQube solving issues but I'm facing a trouble to how handle null pointers that shouldn't be dereferenced. At worst, it could expose debugging information that would be useful to an attacker, or it could allow an attacker to bypass security measures. 1 Answer Sorted by: 1 Your code is ok. 11 Sep, 2006. It is still a pointer though, to use it you just have to cast it to another kind of pointer first. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. If not, this might be a bug. By 'valid pointers' I mean that both src and dest pointers are not null and they both point to non-overlapping arrays containing at least n bytes each. Perhaps this could be done with a special constraint that will notify the SE engine that we learned from a Debug.Assert call. There are many ways to resolve this. Provide a self-contained reproducer (zipped project?) SonarLint: A "NullPointerException" could be thrown; "getBody()" can return null. IDE extension that lets you fix coding issues before they exist! @Tibor SonarQube version 5.6.6, IntelliJ SonarLint plugin 3.0.0.2041, Sonar: Null pointers should not be dereferenced, How Intuit democratizes AI development across teams through reusability. Trying to understand how to get this basic Fourier Series. the Java one). "After the incident", I started to be more careful not to trip over things. int changed to size_t and if size_t parameter's is zero, allocate one word. Doing so will at best cause abrupt program termination, without the This cross-file approach analysis can be quite resource-consuming, and we are not ready to openly enable the feature. How can I check before my flight that the cloud separation requirements in VFR flight rules are met? In C, dereferencing a null pointer is undefined behavior. ), 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. Phew, we're agreed here. Powered by Discourse, best viewed with JavaScript enabled. rev2023.3.3.43278. http://blog.llvm.org/2011/05/what-every-c-programmer-should-know_14.html. How to deal with "java.lang.OutOfMemoryError: Java heap space" error? 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. Is there a proper earth ground point in this switch box? Unfortunately, its actual state also has some limitations, like the one you are hitting here. How can we prove that the supernatural or paranormal doesn't exist? In the simplest case, this function just returns the result of calling kmalloc. Status: Dormant. See "Clever Attack Exploits Fully-Patched Linux Kernel" [Goodin 2009] for an example of a code execution exploit that resulted from a null pointer dereference. Rule squid:S2259 is based on a Symbolic Execution (SE) engine. That makes sense. SonarQube - Null Pointer Dereference Issue java simonsirak (Simon Sirak) June 14, 2018, 1:18pm 1 Hi! Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2. The final NCCE is actually more insidious than it seems at first. validated for null in your method declaration with it: 2008-2023 SonarSource S.A., Switzerland. What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? 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. EXP34-C is a common consequence of ignoring function return values, but it is a distinct error, and can occur in other scenarios too. Is there a single-word adjective for "having exceptionally strong moral principles"? Is there a proper earth ground point in this switch box? How do I align things in the following tabular environment? context.RaiseException , (/) 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. What is the point of Thrower's Bandolier? Null pointer should not be dereferenced , MSBuild SonarQube Runner Resharper Plugin receives skipping info errors File not in sonarqube, SonarQube jenkins plugin returns "Server returned HTTP response code: -1, message: 'null' for URL: https://api.github.com/user", SonarQube: Ignore issues in blocks not working with regex, sonarLint complains "Null pointers should not be dereferenced (squid:S2259)" despite that possibility being handled, Java: (false?) The only potential null is the return value of list(). ", 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". So the first execution of ValidateNumber inside the foreach works fine and valid is set to true.The second execution throws the exception and exception is set in the catch-Block.. At worst, it could expose debugging information that would be useful to an attacker, or it could allow an attacker to . 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. Iflengthhas the value1, the addition yields 0, and png_malloc() subsequently returns a null pointer, which is assigned to chunkdata. Small typo nit: "such as if i t pointed to freed memory" meant to say "if it" instead (removing whitespace). The expected result here is solve the issue with sonarqube. SonarJava Version 5.9.2 (build 16552). Why does the second compliant example permit using possibly-null pointers? Why is there a voltage on my HDMI and coaxial cables? By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. This rule applies to all null pointers, regardless of which function returned them. 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. Thanks, David! "After the incident", I started to be more careful not to trip over things. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. If that variable hasn't had a reference assigned, it's a null reference, which (for internal/historical reasons) is referred to as a null pointer. You're in a company-managed project. It also adds assertions to document that certain other pointers must not be null.
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