null pointers should not be dereferenced

And the compliant solution guarantees that the pointer will be valid if the code calls memcpy(). In C/C++ speak, 'dereferencing' simply means getting the object that a pointer . Im having trouble understanding your problem. The problem is, I hope this code's result to be <5,3> and <9,6> BUT the console only shows me <5,3> and <9,3>. Alternate Terms Relationships At best, such an exception will cause abrupt program termination. IMHO, the rule title should be changed to something less general. Batch split images vertically in half, sequentially numbering the output files, Recovering from a blunder I made while emailing a professor. Software project. It also adds assertions to document that certain other pointers must not be null. What can a lawyer do if the client wants him to be acquitted of everything despite serious evidence? My below code where I'm calling a stored procedure is giving a null pointer exception. 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. Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2. 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. S2259: Null pointers should not be dereferenced java tsubasa (Jiaoyang Ma) January 11, 2019, 6:57am 1 versions used (SonarQube, Scanner, language analyzer) SonarQube Version 6.7.2 (build 37468) SonarJava Version 5.9.2 (build 16552) minimal code sample to reproduce (with analysis parameter, and potential instructions to compile). Does Counterspell prevent from any further spells being cast on a given turn? Removing the check "exception != null" raises S2259 "Null pointers should not be dereferenced" on "throw exception". points to memory allocated to the process) and what exactly was allocated there after the public key was freed, this may cause a segmentation fault or even execute code, which could again cause a segmentation fault, but might potentially be under the attacker's control. SonarQube - Null Pointer Dereference Issue java simonsirak (Simon Sirak) June 14, 2018, 1:18pm 1 Hi! Dereferencing a null pointer can lead to a denial of service. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. 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. How can we prove that the supernatural or paranormal doesn't exist? Obviously the value of that pointer could have changed since the . This compliant solution eliminates the null pointer deference by initializing sk to tun->sk following the null pointer check. Connect and share knowledge within a single location that is structured and easy to search. Thanks for contributing an answer to Stack Overflow! Seems the analizer don't recognice the logic with the funcional object Optional. How can we let this pass? Find centralized, trusted content and collaborate around the technologies you use most. EXP34-C is a common consequence of ignoring function return values, but it is a distinct error, and can occur in other scenarios too. 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. Thanks, David! The result of calling such a helper function should be . In this noncompliant code example, input_str is copied into dynamically allocated memory referenced by c_str. sonarLint (3.2.) Is there a single-word adjective for "having exceptionally strong moral principles"? Pointer members in structs are not checked. rev2023.3.3.43278. If you preorder a special airline meal (e.g. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. 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. But the problem also exists in the compliant version, so I'm not so sure that it's really compliant. That makes sense. 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. it could allow an attacker to bypass security measures. positive S2637 in SonarQube 6.7.1 LTS, SonarQube for MSBuild not reporting quality issues, getTextContent() through "Null pointers should not be dereferenced". Please direct comments on this JSR to the Spec Lead (s) Team. 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. return p == NULL || (char *)p < &_etext; This code also violates ERR33-C. Detect and handle standard library errors. name result . Appropriate typecasting is necessary. 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]. At worst, it could expose debugging information that would be useful to an attacker or it could allow an Java Specification Participation Agreement version in use: 2.0. Not the answer you're looking for? When you have a variable of non-primitive type, it is a reference to an object. Thank you for clarifying your assertion until I understood it properly. , RemoteContext new ExceptionType() RemoteContext , SonarLintJava (), java - sonarLint "Null pointers should not be dereferenced (squid:S2259)"Stack Overflow 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. 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. I have a sonar alert on this call minRating.getRatgCaam(). What is null pointer exception in android. Additionally, if input_str is a null pointer, the call to strlen() dereferences a null pointer, also resulting in undefined behavior. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. The same problem we will have with "Add at least one assertion to this test case." All content is copyright protected. 2008-2023 SonarSource S.A., Switzerland. 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 (?,?,?,?,?,?,?,? Not the answer you're looking for? One could argue that all code examples would be redundant with the first pair. 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 . "After the incident", I started to be more careful not to trip over things. What does "Could not find or load main class" mean? But when length of A is 1, the control never reaches the else block. Such long getter chains can also be replaced with Optional + map + ifPresent lambda style. Goal 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. Not the answer you're looking for? , . Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. But passing 0 to memcpy() is not one of them. 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. util.regex.Matcher, java - Swing .getParent() . Sonar is ok. Sonar can't determine that the helper method did the null validation. Making statements based on opinion; back them up with references or personal experience. An awesome tip to avoid NPE is to return empty strings or empty collections rather than null. Note that it doesn't know how to check for non-heap, non-stack. Recovering from a blunder I made while emailing a professor. Can I tell police to wait and call a lawyer when served with a search warrant? 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. Ticket opened : Thanks a lot for the minimalized reproducer ! It's still illegal. My main problem is because I'm doing a restTemplate.exchange with try-catch and declaring a variable with null value before the clause try and then using it inside the try. 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. When B is null, The control reaches inside the main if block only when length of A is 1. Find centralized, trusted content and collaborate around the technologies you use most. I suggest that this topic needs to include calloc() and realloc() Refer to Linux man pages online for more enlightenment about malloc(), and friends. sonarqube A reference to null should never be dereferenced/accessed. 3.Null pointers should not be derefer enced/accessed. The solution that I recommend is not work with null returns or variables on Java, try to avoid it. So we have to check all the arguments before performing any actions. Is it plausible for constructed languages to be used to affect thought and control or mold people towards desired outcomes? ), NPD.CHECK.CALL.MIGHTNPD.CHECK.CALL.MUSTNPD.CHECK.MIGHTNPD.CHECK.MUSTNPD.CONST.CALLNPD.CONST.DEREFNPD.FUNC.CALL.MIGHTNPD.FUNC.CALL.MUSTNPD.FUNC.MIGHTNPD.FUNC.MUSTNPD.GEN.CALL.MIGHTNPD.GEN.CALL.MUSTNPD.GEN.MIGHTNPD.GEN.MUSTRNPD.CALLRNPD.DEREF, 45 D, 123 D, 128 D, 129 D, 130 D, 131 D, 652 S, Checks for use of null pointers (rule partially covered). To learn more, see our tips on writing great answers. After that, you call res.getBody() again. very old code or C code being worked into c++ may have functions that expect the user to delete the data. The approximation of the try catch flow is such that we consider an exception can be thrown just after the curly brace of the try. static-code-analysis 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 */ What is a NullPointerException, and how do I fix it?,What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them? I added a comment to explain that SIZE_MAX is the limit of size_t. Carnegie Mellon University (/). To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Find centralized, trusted content and collaborate around the technologies you use most. validated for null in your method declaration with it: 2008-2023 SonarSource S.A., Switzerland. "After the incident", I started to be more careful not to trip over things. rev2023.3.3.43278. What is the point of Thrower's Bandolier? Since you cannot have a variable of type void, the pointer will not point to any data and therefore cannot be dereferenced. Asking for help, clarification, or responding to other answers. How can this new ban on drag possibly be considered constitutional? Connect and share knowledge within a single location that is structured and easy to search. Reports. Then we hit memcpy with length 0. 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" Believing that dereferencing NULL shouldn't crash the system doesn't make it true. Do "superinfinite" sets exist? PS: I also tried the code in android studio which uses Lint and got no warnings. It is generally accepted that zeroing a pointer is a good way to mark it as invalid and dereferencing an invalid pointer is a bug. Much like dereferencing a dangling (or wild) pointer leads to undefined behavior, dereferencing a null pointer also leads to undefined behavior. CWE-476: NULL Pointer Dereference: 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. This issues is displayed by SonarQube. Note that 7.1.4 explicitly states that a null pointer is not a valid pointer argument.