it could allow an attacker to bypass security measures. sonarqube On many platforms, dereferencing a null pointer results in abnormal program termination, but this is not required by the standard. Carnegie Mellon University To subscribe to this RSS feed, copy and paste this URL into your RSS reader. That's true. 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. 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. Im having trouble understanding your problem. Fixed by #1156 Contributor 94cb5f8 boris-unckel on Jul 28, 2021 9e62550 boris-unckel mentioned this issue on Jul 28, 2021 Closes #1155 - Null pointers should not be dereferenced #1156 Merged I suggest that this topic needs to include calloc() and realloc() Refer to Linux man pages online for more enlightenment about malloc(), and friends. Please explain: Without this, we wont be able to help you. sonar-java. However, memory allocation > functions such as kstrdup() may fail and returns NULL. Connect and share knowledge within a single location that is structured and easy to search. This code also violates ERR33-C. Detect and handle standard library errors. return p == NULL || (char *)p < &_etext; In Java, a special null value can be assigned to an object reference. The null concept refers to the idea that a pointer can hold a special value that is not equal to another pointer. Depending on whether the pointer is valid (i.e. Since you cannot have a variable of type void, the pointer will not point to any data and therefore cannot be dereferenced. Status: Dormant. I would therefore assert that a platform whose memcpy() did anything besides a no-op when given n=0 and valid source/destination pointers was not C-standards-compliant. We can see that at obj.run(), obj can not be null, but is pointed out by Sonar. validated for null in your method declaration with it: 2008-2023 SonarSource S.A., Switzerland. 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]. Null pointer should not be dereferenced . 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. Hello. Doing so will cause a NullReferenceException to be thrown. Alternate Terms Relationships The same problem we will have with "Add at least one assertion to this test case." SonarQube Version 6.7.2 (build 37468) 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. Can you please start a new thread and be more explicit about the issue you are observing. Do "superinfinite" sets exist? However there is no portable way to verify that the pointer is valid, other than checking for null. 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 SONAR, SONARSOURCE, SONARLINT, SONARQUBE and SONARCLOUD are trademarks of SonarSource S.A. All other trademarks and copyrights are the property of their respective owners. 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. As for today, the SE engine is able to explore non-overridable methods (static, for instance), when declared in the same file being analyzed. 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. You need to benchmark. What is a serialVersionUID and why should I use it? 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. But even with this, the concerned object it tagged as a possible NullPointerException problem. I would also guess that pointers that point to the one-past-the-end of an array are also invalid. Made code more compliant with other rules. Some Interesting Facts: 1) void pointers cannot be dereferenced. ), 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. 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. What is null pointer exception in android. My below code where I'm calling a stored procedure is giving a null pointer exception. To learn more, see our tips on writing great answers. In layman's terms, a null pointer is a pointer to an address in the memory space that does not have a meaningful value and cannot be referenced by the calling program, for whatever reason. 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. False-positives are pointed out in other SO posts (1 & 2), where nulls are involved across functions and procedures. What does "Could not find or load main class" mean? 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. But when length of A is 1, the control never reaches the else block. Why do academics stay as adjuncts for years rather than move around? Minimising the environmental effects of my dyson brain. {"serverDuration": 214, "requestCorrelationId": "084acdc104f21c51"}, EXP34-C. Do not dereference null pointers, Clever Attack Exploits Fully-Patched Linux Kernel, ERR33-C. Detect and handle standard library errors, one compliant and one non-compliant example, CERT Oracle Secure Coding Standard for Java, EXP01-J. java That is, sets equivalent to a proper subset via an all-structure-preserving bijection. Whats the grammar of "For those whose stories they are"? 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. At worst, it could expose debugging information that would be useful to an attacker, or it could allow an attacker to . Currently I'm working with SonarQube solving issues but I'm facing a trouble to how handle null pointers that shouldn't be dereferenced. But the problem also exists in the compliant version, so I'm not so sure that it's really compliant. To be precise, once length is changed to a size_t and cannot take negative values, it cannot have an invalid value. Thank you for clarifying your assertion until I understood it properly. Key here (explains table format and definitions), EXP34-C = Union( CWE-690, list) where list =. I am a student implementing stack with singly linked list using C, following a book called Fundamentals of Data Structures in C.. Haiku is a free and open-source operating system for PC designed to be binary compatible with the BeOS operating system and embodying the basic ideas of BeOS. Doing so will cause a NullPointerException to be thrown. There is no legitimate reason to dereference a null pointer unless you on a rare system that maps page zero (or you intend your program to crash). I don't need to do this validation again. 3.Null pointers should not be derefer enced/accessed. This is a feature that we are currently heavily working on to be able to switch off such kind of false positives. Software Engineering Institute Optimizers are optimizing based on this latitude and have been for years. Asking for help, clarification, or responding to other answers. 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. Is it possible to create a concave light? Im currently using SonarQube version 5.6.6. better way to handle this is to store the result of method invocation in a variable. We can get a reference to point to null in the following ways: "uninitialized" reference type variables variables which are initialized with nulls and are assigned their real value afterward. (/). Because null pointer dereferencing is undefined behavior, the compiler (GCC in this case) can optimize away the if (!tun) check because it is performed after tun->sk is accessed, implying that tun is non-null. The 2nd NCCE/CS pair seems redundant with the first NCCE/CS pair. 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. 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. Setup is effortless and analysis is automatic for most languages, Fast, accurate analysis; enterprise scalability. When B is null, The control reaches inside the main if block only when length of A is 1. 5.2 Part 2 Sometimes a helper function is de ned to perform the memory allocation. 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. Is it plausible for constructed languages to be used to affect thought and control or mold people towards desired outcomes? Not the answer you're looking for? 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. This issues is displayed by SonarQube. There is no guarantee that subsequent invocations are returning the same value, thats why issue is raised. I have checked on multiple . ability to run any cleanup processes. But when length of A is 1, the control never reaches the else block. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Believing that dereferencing NULL shouldn't crash the system doesn't make it true. Report False-positive / False-negative [LTS] The new SonarQube LTS is here: SONARQUBE 9.9 LTS, SonarQube - Null Pointer Dereference Issue. Why are physically impossible and logically impossible concepts considered separate in terms of probability? 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. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. To create a custom null validation method declare an attribute with name ValidatedNotNullAttribute and mark the parameter that is Such long getter chains can also be replaced with Optional + map + ifPresent lambda style. 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. 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. This sounds indeed like a bug in the flow when an exception is raised. The SonarJava SE engine is however, by default, not configured to explore methods declared in other files (in your case, your utility class CheckUtils). Dereferencing > this null pointer may cause the kernel go wrong. IMHO, the rule title should be changed to something less general. Your code needs to do something about the possible NullPointerException when some exception is caught, because in this scenario the responseDto will be null. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. which version of SonarQube are you using? Dereferencing a null pointer results in undefined behavior.
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