1 Answer Sorted by: 2 Your code needs to do something about the possible NullPointerException when some exception is caught, because in this scenario the responseDto will be null. ii. Now, you can find the list of whitelisted methods here. 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. Made code more compliant with other rules. The solution that I recommend is not work with null returns or variables on Java, try to avoid it. ucsi->connector gets dereferenced by both ucsi_connector_change() and ucsi_resume(), both check for ucsi->connector being NULL in case ucsi_init() has not finished yet; or in case ucsi_init() has failed. I suggest that this topic needs to include calloc() and realloc() Refer to Linux man pages online for more enlightenment about malloc(), and friends. Asking for help, clarification, or responding to other answers. That is, sets equivalent to a proper subset via an all-structure-preserving bijection. What does "Could not find or load main class" mean? In C/C++ speak, 'dereferencing' simply means getting the object that a pointer . Im very new to sonar, is there a way to add methods to the whitelist? uninitialized reference-type class members. And if there is no pointer_default declaration, then the default default is ref. Because a null pointer does not point to a meaningful object, an attempt to dereference(i.e., access the data stored at that memory location) a null pointer usually (but not always) causes a run-time error or immediate program crash. Is it plausible for constructed languages to be used to affect thought and control or mold people towards desired outcomes? We might set a pointer to null even if we are not freeing a object, simply to dissociate one object from another: tty_driver->tty = NULL; /* detach low level driver from the tty device */ sonarLint (3.2.) These can be: Invoking a method from a null object. This is a feature that we are currently heavily working on to be able to switch off such kind of false positives. Note that 7.1.4 explicitly states that a null pointer is not a valid pointer argument. At Connect and share knowledge within a single location that is structured and easy to search. I have checked on multiple . validated for null in your method declaration with it: 2008-2023 SonarSource S.A., Switzerland. When and how should I use a ThreadLocal variable? The expected result here is solve the issue with sonarqube. raiseException() return, Sonar 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. public boolean isNameEmpty() { return getName().length() == 0; // Noncompliant; the result of getName() could be null, but isn't null-checked } . Do "superinfinite" sets exist? On such a call, a function that locates a character finds no occurrence, a function that compares two character sequences returns zero, and a function that copies characters copies zero characters. Find centralized, trusted content and collaborate around the technologies you use most. This solution also ensures that theuser_data pointer is not null. Trying to understand how to get this basic Fourier Series. Optimizers are optimizing based on this latitude and have been for years. The alert is related to the sonar rule : Null pointers should not be dereferenced. I believe in this case, either expression would work. When and how should I use a ThreadLocal variable? Making statements based on opinion; back them up with references or personal experience. Find centralized, trusted content and collaborate around the technologies you use most. Calls to extension methods are not reported because they can still operate on null values. We resolved it by adding our tools path in the white list, and repackaging it. Why do academics stay as adjuncts for years rather than move around? SONAR, SONARSOURCE, SONARLINT, SONARQUBE and SONARCLOUD are trademarks of SonarSource S.A. All other trademarks and copyrights are the property of their respective owners. How do I align things in the following tabular environment? You can use Optional instead. SONAR, SONARSOURCE, SONARLINT, SONARQUBE and SONARCLOUD are trademarks of SonarSource S.A. All other trademarks and copyrights are the property of their respective owners. Can I tell police to wait and call a lawyer when served with a search warrant? 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. Issues Components. Removing the check "exception != null" raises S2259 "Null pointers should not be dereferenced" on "throw exception". I would also guess that pointers that point to the one-past-the-end of an array are also invalid. 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.) It is still a pointer though, to use it you just have to cast it to another kind of pointer first. We. 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. 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. How can this new ban on drag possibly be considered constitutional? This issues is displayed by SonarQube. Correct; a null pointer is not a valid pointer for the C library functions. I've changed it to say null pointer instead of invalid pointer. Whats the grammar of "For those whose stories they are"? Note that it doesn't know how to check for non-heap, non-stack. Trying to understand how to get this basic Fourier Series. Coverity Prevent cannot discover all violations of this rule, so further verification is necessary, Detects when NULL is dereferenced (Array of pointers is not checked. Null pointer should not be dereferenced , How can I check before my flight that the cloud separation requirements in VFR flight rules are met? Reports. Making statements based on opinion; back them up with references or personal experience. What is generic pointer? What is a serialVersionUID and why should I use it? The article easily misleads the reader into believeing that ensuring pointer validity boils down to checking for pointer being not equal to NULL. In this noncompliant code example, input_str is copied into dynamically allocated memory referenced by c_str. But passing 0 to memcpy() is not one of them. It is useful to have a function with portable interface but platform-dependent implementation: extern bool invalid(const void *); On many platforms, dereferencing a null pointer results in abnormal program termination, but this is not required by the standard. Since you cannot have a variable of type void, the pointer will not point to any data and therefore cannot be dereferenced. Thanks, David! Not the answer you're looking for? This compliant solution ensures that both input_str andthe pointer returned by malloc() are not null: This noncompliant code example is from a version of drivers/net/tun.c and affects Linux kernel 2.6.30 [Goodin 2009]: The sk pointer is initialized to tun->sk before checking if tun is a null pointer. To learn more, see our tips on writing great answers. 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. Currently I'm working with SonarQube solving issues but I'm facing a trouble to how handle null pointers that shouldn't be dereferenced. As a result, this noncompliant code example is vulnerable to a null pointer dereference exploit, because null pointer dereferencing can be permitted on several platforms, for example, by using mmap(2) with the MAP_FIXED flag on Linux and Mac OS X, or by using the shmat() POSIX function with the SHM_RND flag [Liu 2009]. 1 Answer Sorted by: 1 Your code is ok. 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. So no checking of the length is necessary (besides preventing integer overflow, which the compliant solution does). In Java, a special null value can be assigned to an object reference. This is a matter of style, and also following code walkthrough. The libpng library allows applications to read, create, and manipulate PNG (Portable Network Graphics) raster image files. Mutually exclusive execution using std::atomic? NullPointerException is a RuntimeException. Minimising the environmental effects of my dyson brain. 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. The problem is that something like %*pbl which reads a bitmask, will save the pointer to the bitmask in the buffer. Much like dereferencing a dangling (or wild) pointer leads to undefined behavior, dereferencing a null pointer also leads to undefined behavior. Please direct comments on this JSR to the Spec Lead (s) Team. extern char _etext; This likely means that youre on an ancient version of the Java analyzer. Unlike reference types, pointer types are not tracked by the default garbage . If the project is not compiled, and without sonar.java.binaries whether the white list takes effect? Then we hit memcpy with length 0. 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. So Bar might not be initialized but then the last line of your example should not be evaluated in this case. void *pointerVariableName = NULL; Since they are very general in nature, they are also known as generic pointers. Alternate Terms Relationships attacker to bypass security measures. Iflengthhas the value1, the addition yields 0, and png_malloc() subsequently returns a null pointer, which is assigned to chunkdata. What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? "After the incident", I started to be more careful not to trip over things. the Java one). name result . Put a new ResponseEntity is wrong because I won't know what will be the answer for the status of http. 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. ssize_t (*aio_read)(struct kiocb *, char __user *, size_t . The idea is not to guarantee validity, but to catch a substantial number of problems that could occur. Software Engineering Institute