// <------- 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. Making statements based on opinion; back them up with references or personal experience. The return value from strchr() is often NULL, but the dev might know that a specific strchr() function call will not return NULL. The SonarJava SE engine is however, by default, not configured to explore methods declared in other files (in your case, your utility class CheckUtils). rev2023.3.3.43278. What is a NullPointerException, and how do I fix it? The user_data pointer could be invalid in other ways, such as pointing to freed memory. SONAR, SONARSOURCE, SONARLINT, SONARQUBE and SONARCLOUD are trademarks of SonarSource S.A. All other trademarks and copyrights are the property of their respective owners. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. You're in a company-managed project. extern char _etext; The correct idiom is to only allocate storage if the pointer is currently NULL. It could be non-null the first time but not the second time, sonar does not know this. Not the answer you're looking for? I suggest that this topic needs to include calloc() and realloc() Refer to Linux man pages online for more enlightenment about malloc(), and friends. Privacy Policy, Detect issues in your GitHub, Azure DevOps Services, Bitbucket Cloud, GitLab repositories. rev2023.3.3.43278. IMHO, the rule title should be changed to something less general. very old code or C code being worked into c++ may have functions that expect the user to delete the data. Answered: difference between a void pointer and a | bartleby I doubt that "length" of zero is a valid parameter, and although there no copy, but we see memory allocation. Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2. Pittsburgh, PA 15213-2612 Sonar false-positive on rule: Null pointers should not be dereferenced Styling contours by colour and by line thickness in QGIS. IDE extension that lets you fix coding issues before they exist! 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. SonarLint: A "NullPointerException" could be thrown; "getBody()" can return null. Im having trouble understanding your problem. The solution that I recommend is not work with null returns or variables on Java, try to avoid it. Why are Suriname, Belize, and Guinea-Bissau classified as "Small Island Developing States"? A reference to null should never be dereferenced/accessed. Why pointers are not used in python? Explained by Sharing Culture Mutually exclusive execution using std::atomic? 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. 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. SonarQube null pointers should not be dereferenced on try/catch Connect and share knowledge within a single location that is structured and easy to search. I feel my situation is not as complicated. However, memory allocation > functions such as kstrdup() may fail and returns NULL. Automated Detection Null pointer dereferences can happen in path-dependent ways. When a variable is declared as being a pointer to type void, it is known as a generic pointer. 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 it suspicious or odd to stand by the gate of a GA airport watching the planes? [4] String *x, y; X is a pointer to a string, Y is a string & = address of variable/ operator || referencing operator * = value of address || dereferencing operator Pointers = stores memory address as its variables NULL pointer = a constant with a value of zero defined || assigned to null Void pointer = a pointer that is not associated with any data types New operator = denotes a request for . Good question! Please direct comments on this JSR to the Spec Lead (s) Team. How can we prove that the supernatural or paranormal doesn't exist? To be precise, once length is changed to a size_t and cannot take negative values, it cannot have an invalid value. How can we let this pass? I reordered that code example to do all the checks before allocations. Analysis of Haiku Operating System (BeOS Family) by PVS-Studio. Part 1 I guess you could write a proposal to modify the C Standard, but our coding standard is meant to provide guidance for the existing language. But passing 0 to memcpy() is not one of them. Believing that dereferencing NULL shouldn't crash the system doesn't make it true. What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? (in the meantime, in case of any other false-positive suspicion, make sure to check those latest versions as bunch of improvements are regularly released). 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. SonarJava. The same problem we will have with "Add at least one assertion to this test case." Whoops, you're right. If you call connect() function, it better do the connection, but failing simply because some ptr is NULL is not good behaviour -- failures should . That makes sense. The n=0 is a mildly interesting edge case: Clearly a pointer that points to at least one valid byte could be used as the src or dest pointer to a call to memcpy(, 0). Maybe one of these methods is already doing what your methods is doing, and could be considered as replacement. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. 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. Not the answer you're looking for? At worst, it could expose debugging information that would be useful to an attacker, or it could allow an attacker to . C# static code analysis: HTTP responses should not be vulnerable to Goal Trying to understand how to get this basic Fourier Series. 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. Doing so will cause a NullReferenceException to be thrown. You're in a company-managed project. 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. But no where in that particular idiom would a NULL pointer necessarily be deferenced. You need to benchmark. 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. 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. That noncompliant code example (it's currently the 3rd) came from the Linux kernel, whose source is publicly available. . PDF Fourth Coccinelle Workshop { Exercises () Then the reading of the buffer via bstr_printf() will then look at the pointer to process the final output. Thanks, David! Asking for help, clarification, or responding to other answers. 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. Software project. Pointers in C Explained - They're Not as Difficult - freeCodeCamp.org Carnegie Mellon University 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.. The 2nd NCCE/CS pair seems redundant with the first NCCE/CS pair. which would allow us to systematically observe what you are having. A common memory-leak idiom, is reallocating storage and assigning its address to a pointer that already points to allocated storage. 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 null pointer check for writing or dereferencing should be a compiler flag or library setting. [squid:S2259] False positive - "Null pointers should not be dereferenced" What sort of strategies would a medieval military use against a fantasy giant? At worst, it could expose debugging information that would be useful to an attacker or it could allow an versions used (SonarQube, Scanner, language analyzer) By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. in above code, uninitialized reference-type class members. 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. For the time being, I would unfortunately recommend to mark as False Positive the issue. The issue arises when dereferenced pointers are used. http://blog.llvm.org/2011/05/what-every-c-programmer-should-know_14.html. Since SIZE_MAX represents the largest possible object, the largest possible string would then be SIZE_MAX-1 characters long (excluding '\0'). rev2023.3.3.43278. Find centralized, trusted content and collaborate around the technologies you use most. Pointer Arithmetic in c - Unit - 4 1. Define pointer. Explain about the What is generic pointer? Asking for help, clarification, or responding to other answers. Also, the term 'pointer' is bad (but maybe it comes from the FindBugs tool): Java doesn't have pointers, it has references. It could be non-null the first time but not the second time, sonar does not know this. What is the point of Thrower's Bandolier? Hi Andreas, Thanks for the feedback. Does it just mean failing to correctly check if a value is null? Thanks for contributing an answer to Stack Overflow! Passing a null pointer tomemcpy() would produce undefined behavior, even if the number of bytes to copy were 0. Trying to understand how to get this basic Fourier Series. In some situations, however, dereferencing a null pointer can lead to the execution of arbitrary code [Jack 2007,van Sprundel 2006]. This cross-file approach analysis can be quite resource-consuming, and we are not ready to openly enable the feature. SonarQube Version 6.7.2 (build 37468) Batch split images vertically in half, sequentially numbering the output files, Recovering from a blunder I made while emailing a professor. Two null pointers will always be equal to each other. A NULL pointer can be dereferenced when signatures are being verified on PKCS7 signed or signedAndEnveloped data. When I added the not null validation as sonar suggest. Is it plausible for constructed languages to be used to affect thought and control or mold people towards desired outcomes? Does a summoned creature play immediately after being summoned by a ready action? which version of SonarQube are you using? Setup is effortless and analysis is automatic for most languages, Fast, accurate analysis; enterprise scalability. Why do academics stay as adjuncts for years rather than move around?
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