Making statements based on opinion; back them up with references or personal experience. 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 . 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 method isNR(minRating) is a helper method that validate among other things, if the object minRating is null. On the command prompt, the same arguments work and the record is added in db but not when I call the stored procedure from inside java program CallableStatement insertStat = db_conn.prepareCall (" {call InsertCourses (?,?,?,?,?,?,?,? 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.) Thanks, David! 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. Trying to understand how to get this basic Fourier Series. This topic was automatically closed 7 days after the last reply. Automated Detection Null pointer dereferences can happen in path-dependent ways. I suppose there is a question of "Is a pointer that points to 0 bytes valid?" 5.2 Part 2 Sometimes a helper function is de ned to perform the memory allocation. Why do academics stay as adjuncts for years rather than move around? Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2. http://blog.llvm.org/2011/05/what-every-c-programmer-should-know_14.html. A value is checked here to see whether it is null, but this value can't be null because it was previously dereferenced and if it were null a null pointer exception would have occurred at the earlier dereference. Why are physically impossible and logically impossible concepts considered separate in terms of probability? To be precise, once length is changed to a size_t and cannot take negative values, it cannot have an invalid value. But when length of A is 1, the control never reaches the else block. 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. 11 Sep, 2006. This is a feature that we are currently heavily working on to be able to switch off such kind of false positives. The libpng library allows applications to read, create, and manipulate PNG (Portable Network Graphics) raster image files. Hi Andreas, Thanks for the feedback. This rule applies to all null pointers, regardless of which function returned them. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. null(java.lang.NullPointerException) . Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2. In my experience, there are reasons to check for a NULL pointer other than dereferencing it. You need to benchmark. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. When I scan with sonar-lint in idea, it seams white list is useful, but when use sonar-scanner, always FP, org.springframework.util.CollectionUtils#isEmpty Is there a single-word adjective for "having exceptionally strong moral principles"? Is there a proper earth ground point in this switch box? What methods/tools can be used to determine the cause so that you stop the exception from causing the progra. Unfortunately, its actual state also has some limitations, like the one you are hitting here. How can I check before my flight that the cloud separation requirements in VFR flight rules are met? (I think you cover that in a different rule.) The solution that I recommend is not work with null returns or variables on Java, try to avoid it. The problem is that something like %*pbl which reads a bitmask, will save the pointer to the bitmask in the buffer. EXP34-C is a common consequence of ignoring function return values, but it is a distinct error, and can occur in other scenarios too. We have a false positive with the " Null pointers should not be dereferenced -squid:S2259" rule : We have a "NullPointerException" false positive for which we do not know how to solve it. Thanks for the feedback. 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. I added an assertion to that compliant code example. Please direct comments on this JSR to the Spec Lead (s) Team. But even with this, the concerned object it tagged as a possible NullPointerException problem. - the incident has nothing to do with me; can I use this this way? 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 Calls to extension methods are not reported because they can still operate on null values. Instead use String.valueOf (object). In multithreaded programs, null pointer dereferences can violate cache coherency policies and can cause resource leaks. SIZE_MAX is the largest possible value that a size_t could take, so it is not possible to have anything larger than SIZE_MAX. Why are Suriname, Belize, and Guinea-Bissau classified as "Small Island Developing States"? uninitialized reference-type class members. 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. Explain about call by reference with an . return p == NULL || (char *)p < &_etext; On many platforms, dereferencing a null pointer results in abnormal program termination, but this is not required by the standard. Accessing or modifying a null object's field. This solution also ensures that theuser_data pointer is not null. ), 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. Your code needs to do something about the possible NullPointerException when some exception is caught, because in this scenario the responseDto will be null. Is there a solution to add special characters from software and how to do it, Acidity of alcohols and basicity of amines. Thanks for contributing an answer to Stack Overflow! 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). 0 is a valid value as far as memcpy() is concerned, and malloc() has special language concerning malloc(0). 412-268-5800, If an argument to a function has an invalid value (such as a value outside the domain of the function, or a pointer outside the address space of the program, or a null pointer, or a pointer. That is only true if possibleNumbers contains no element.. BTW: none of these warnings are shown by . Possible fix: Assign a valid address to the pointer in all branches of the conditional statement.. Pointer can point to dynamically allocated memory. Appropriate typecasting is necessary. Is the God of a monotheism necessarily omnipotent? Share Improve this answer Follow answered Oct 5, 2017 at 16:27 Good question! How to deal with "java.lang.OutOfMemoryError: Java heap space" error? 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. rev2023.3.3.43278. )}"); Two null pointers will always be equal to each other. Small typo nit: "such as if i t pointed to freed memory" meant to say "if it" instead (removing whitespace). We really appreciate your help. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Basically, yes. which version of SonarQube are you using? isEmpty(Collection collection) @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. That is, sets equivalent to a proper subset via an all-structure-preserving bijection. I believe that dereferencing NULL should not crash the system, should not allow a write to a NULL pointer area, but should always set errno, If I am a hacker, could I trap a null failure that would force a memory dump. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. False-positives are pointed out in other SO posts (1 & 2), where nulls are involved across functions and procedures. (In contrast, the case of passing 0 bytes to malloc is addressed in C11.) Privacy Policy, Detect issues in your GitHub, Azure DevOps Services, Bitbucket Cloud, GitLab repositories. Much like dereferencing a dangling (or wild) pointer leads to undefined behavior, dereferencing a null pointer also leads to undefined behavior. Now (sonarqube java analyzer version 4.3.0.7717) it's supported and works fine. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Not the answer you're looking for? Why is there a voltage on my HDMI and coaxial cables? IDE extension that lets you fix coding issues before they exist! Asking for help, clarification, or responding to other answers. This sounds indeed like a bug in the flow when an exception is raised. ncdu: What's going on with this second size column? NULL vs Void Pointer - Null pointer is a value, while void pointer is a type. This cross-file approach analysis can be quite resource-consuming, and we are not ready to openly enable the feature. Believing that dereferencing NULL shouldn't crash the system doesn't make it true. 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. There are many ways to resolve this. In the complaint version, I like to make source code checking a little quicker by putting parenthesizes around arguments to |= or &= as. At best, such an exception will cause abrupt program termination. Depending on whether the pointer is valid (i.e. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Is it suspicious or odd to stand by the gate of a GA airport watching the planes? If you call connect() function, it better do the connection, but failing simply because some ptr is NULL is not good behaviour -- failures should . I would also guess that pointers that point to the one-past-the-end of an array are also invalid. What does "Could not find or load main class" mean? See the "Null pointer checks may be optimized away more aggressively" section inhttps://gcc.gnu.org/gcc-4.9/porting_to.htmlas an example with one common implementation. IMHO, the rule title should be changed to something less general. https://stackoverflow.com/questions/47534436/, https://stackoverflow.com/questions/47534436/, java - Jenkins groovy : Error: java. Did any DOS compatibility layers exist for any UNIX-like systems before DOS started to become outmoded? You're in a company-managed project. The 2nd NCCE/CS pair seems redundant with the first NCCE/CS pair. 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. Using Kolmogorov complexity to measure difficulty of problems? I think "res.getBody() == null" checks null first so it should go to return line, not reach to next if condition. That interpretation of the standard is not supported universally. This compliant solution ensures that the pointer returned by png_malloc() is not null. 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. If malloc() fails, it returns a null pointer that is assigned to c_str. . At 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. 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 */ Null pointers should not be dereferenced. What sort of strategies would a medieval military use against a fantasy giant? Identify where the allocation occurs. On many platforms, dereferencing a null pointer results inabnormal program termination, but this is not required by the standard. Dereferencing > this null pointer may cause the kernel go wrong. Agreed. However there is no portable way to verify that the pointer is valid, other than checking for null. 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. NULL vs Uninitialized pointer - An uninitialized pointer stores an undefined value. Just because something is a pointer does not mean you should call delete . SonarQube Version 6.7.2 (build 37468) At this point we define size as strlen(input_str) + 1. Ah, gotcha. Software Engineering Institute
In some situations, however, dereferencing a null pointer can lead to the execution of arbitrary code [Jack 2007,van Sprundel 2006]. Setup is effortless and analysis is automatic for most languages, Fast, accurate analysis; enterprise scalability. Is it possible to rotate a window 90 degrees if it has the same length and width? Please explain: Without this, we wont be able to help you. 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. But when length of A is 1, the control never reaches the else block. My code is GPL licensed, can I issue a license to have my code be distributed in a specific MIT licensed project? That is why I explicitly check for this in my attempted solution. Recovering from a blunder I made while emailing a professor. I suppose we can check that that is not null, but we cannot check that it is valid (in any portable way). To learn more, see our tips on writing great answers. sonar-java. See C17 7.1.4p1, which says, in part: Each of the following statements applies unless explicitly stated otherwise in the detailed descriptions that follow: If an argument to a function has an invalid value (such as a value outside the domain of the function, or a pointer outside the address space of the program, or a null pointer, or a pointerto 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. It could be non-null the first time but not the second time, sonar does not know this. So we have to check all the arguments before performing any actions. You're in a company-managed project. I already tried to put ResponseEntity
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