Key here (explains table format and definitions), EXP34-C = Union( CWE-690, list) where list =. It means this is illegal: T* p = nullptr; T& r = *p; // illegal NOTE: Please do not email us saying the above works on your particular version of your particular compiler. Note that 7.1.4 explicitly states that a null pointer is not a valid pointer argument. This sounds indeed like a bug in the flow when an exception is raised. Passing ownership of something also requires pointers. SonarJava Version 5.9.2 (build 16552). This noncompliant code example is derived from a real-world example taken from a vulnerable version of the libpng library as deployed on a popular ARM-based cell phone [Jack 2007]. The method takes a relation name r as input, executes the query "select * from r," and prints the result out in tabular format with the attribute names displayed in the table's header; the attribute names are displayed in the table's header. You're in a company-managed project. sonarlint, sonarLint (3.2.) I have a sonar alert on this call minRating.getRatgCaam(). How can we prove that the supernatural or paranormal doesn't exist? A pointer is simply a variable that contains a memory address. In some situations, however, dereferencing a null pointer can lead to the execution of arbitrary code [Jack 2007,van Sprundel 2006]. You do not have permission to delete messages in this group, Either email addresses are anonymous for this group or you need the view member email addresses permission to view the original message. This cross-file approach analysis can be quite resource-consuming, and we are not ready to openly enable the feature. An awesome tip to avoid NPE is to return empty strings or empty collections rather than null. The final NCCE is actually more insidious than it seems at first. int changed to size_t and if size_t parameter's is zero, allocate one word. Null pointer should not be dereferenced , Search for vulnerabilities resulting from the violation of this rule on the CERT website. It also uses the unsigned type size_t to pass the length parameter, ensuring that negative values are not passed to func(). res.getBody() == null || res.getBody().getServiceResult() == null). Find centralized, trusted content and collaborate around the technologies you use most. Asking for help, clarification, or responding to other answers. Explain about call by reference with an . You're in a company-managed project. Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2. Making statements based on opinion; back them up with references or personal experience. 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. minimal code sample to reproduce (with analysis parameter, and potential instructions to compile). SonarJava. Dereferencing a null pointer results in undefined behavior. Alternate Terms Relationships My question is; is my solution incorrect? Pittsburgh, PA 15213-2612 What is a NullPointerException, and how do I fix it?,What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them? 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. The SonarJava SE engine is however, by default, not configured to explore methods declared in other files (in your case, your utility class CheckUtils). When B is null, The control reaches inside the main if block only when length of A is 1. In the simplest case, this function just returns the result of calling kmalloc. vegan) just to try it, does this inconvenience the caterers and staff? Identify where the allocation occurs. 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. On many platforms, dereferencing a null pointer results in abnormal program termination, but this is not required by the standard. I suppose we can check that that is not null, but we cannot check that it is valid (in any portable way). Here is our source code: Sign in to download full-size image The user_data pointer could be invalid in other ways, such as pointing to freed memory. I could've fixed this by changing else to else if (B != null && B.length == 1), but doing so rewards me with warning "condition(B != null && B.length == 1) is always true". A null pointer in this position causes the read system call to fail with -EINVAL ("Invalid argument"). Pointer members in structs are not checked. NullPointerException is a RuntimeException. This is a matter of style, and also following code walkthrough. All content is copyright protected. This code also violates ERR33-C. Detect and handle standard library errors. Iflengthhas the value1, the addition yields 0, and png_malloc() subsequently returns a null pointer, which is assigned to chunkdata. 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, This error was found in the following code: else if (foo.list().length > 0) { }, I attempted to resolve this by rewriting as: else if (null != foo.list() && foo.list().length > 0) { }, foo is an instance of the File class in Java, and is directly instantiated through new File(). 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). isEmpty(Map map) There are other problems with this code, as is noted in the rule. I've changed it to say null pointer instead of invalid pointer. Depending on whether the pointer is valid (i.e. }. 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. Not the answer you're looking for? 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. On many platforms, dereferencing a null pointer results inabnormal program termination, but this is not required by the standard. But passing 0 to memcpy() is not one of them. Trying to understand how to get this basic Fourier Series. , NPE : null-, . The standard will simply copy 0 byteswhich is essentially a no-op. JCP version in use: 2.6. Recovering from a blunder I made while emailing a professor. Much like dereferencing a dangling (or wild) pointer leads to undefined behavior, dereferencing a null pointer also leads to undefined behavior. Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2, Sonar: Null pointers should not be dereferenced, Why should Java 8's Optional not be used in arguments, Sonar alert : "private" methods that don't access instance data should be "static", sonarLint complains "Null pointers should not be dereferenced (squid:S2259)" despite that possibility being handled, Java: (false?) Please explain: Without this, we wont be able to help you. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Small typo nit: "such as if i t pointed to freed memory" meant to say "if it" instead (removing whitespace). Setup is effortless and analysis is automatic for most languages, Fast, accurate analysis; enterprise scalability. Connect and share knowledge within a single location that is structured and easy to search. Can you please start a new thread and be more explicit about the issue you are observing. So no checking of the length is necessary (besides preventing integer overflow, which the compliant solution does). To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Making statements based on opinion; back them up with references or personal experience. Privacy Policy, Detect issues in your GitHub, Azure DevOps Services, Bitbucket Cloud, GitLab repositories. 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. I reordered that code example to do all the checks before allocations. Which @NotNull Java annotation should I use? positive S2637 in SonarQube 6.7.1 LTS, SonarQube for MSBuild not reporting quality issues, getTextContent() through "Null pointers should not be dereferenced". rev2023.3.3.43278. which would allow us to systematically observe what you are having. Since you cannot have a variable of type void, the pointer will not point to any data and therefore cannot be dereferenced. And if there is no pointer_default declaration, then the default default is ref. I would also guess that pointers that point to the one-past-the-end of an array are also invalid. Cause we need throw our own Runtime Exception, well-known methods wont help. ", Eclipse - Sonar S2629 possible false positive with new String, SonarQube null pointers should not be dereferenced on try/catch, getTextContent() through "Null pointers should not be dereferenced". NULL vs Void Pointer - Null pointer is a value, while void pointer is a type. The return value from strchr() is often NULL, but the dev might know that a specific strchr() function call will not return NULL. After that, you call res.getBody() again. I have checked on multiple . Batch split images vertically in half, sequentially numbering the output files, Recovering from a blunder I made while emailing a professor. SONAR, SONARSOURCE, SONARLINT, SONARQUBE and SONARCLOUD are trademarks of SonarSource S.A. All other trademarks and copyrights are the property of their respective owners. Obviously the value of that pointer could have changed since the . The expected result here is solve the issue with sonarqube. This sounds indeed like a bug in the flow when an exception is raised. Do not use a null in a case where an object is required, https://gcc.gnu.org/gcc-4.9/porting_to.html, Prior to 2018-01-12: CERT: Unspecified Relationship, Pointer Casting and Pointer Type Changes [HFC], Dereferencing an out-of-domain pointer [nullref], Section 5.2.18, "Null-Pointer Dereference", Dereferencing null pointers that were not returned by a function. context.RaiseException , (/) If you say [in] or [out] without a modifier, then the modifier defaults to the pointer_default for the enclosing class. If the project is not compiled, and without sonar.java.binaries whether the white list takes effect? Not the answer you're looking for? By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. My code is GPL licensed, can I issue a license to have my code be distributed in a specific MIT licensed project? Issues Components. Description The program can potentially dereference a null pointer, thereby raising a NullPointerException. Solution 1, it looks like, today's solution tomorrow's problem. Not the answer you're looking for? Asking for help, clarification, or responding to other answers. Thanks for contributing an answer to Stack Overflow! Thus we should check > this kstrdup() operation. Revert Update S2259: "Null pointer dereference" CFG should ignore expressions in Debug.Assert #397 Introduce means to not raise "Expression always true/false" on values that were checked with Debug.Assert. 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). ), 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). Accessing or modifying a null object's field. Dereferencing > this null pointer may cause the kernel go wrong. Finally, there is the matter of the compliant solution. There is a missing check for the return value from . When exploring such methods, the engine then deduces behaviors regarding null-checking (among other things). Passing a null pointer tomemcpy() would produce undefined behavior, even if the number of bytes to copy were 0. 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. One could argue that all code examples would be redundant with the first pair. The only potential null is the return value of list(). Can I tell police to wait and call a lawyer when served with a search warrant? Removing the check "exception != null" raises S2259 "Null pointers should not be dereferenced" on "throw exception". Consider the following scenario: you are asked to create a Java class MetaDisplay that contains a static void printTable(String r) method. How can I check before my flight that the cloud separation requirements in VFR flight rules are met? Extended Description NULL pointer dereference issues can occur through a number of flaws, including race conditions, and simple programming omissions. That's true. Software project. A reference to null should never be dereferenced/accessed. That makes sense. Ah, gotcha. , . What is a serialVersionUID and why should I use it? Phew, we're agreed here. ), 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. Instead use String.valueOf (object). This topic was automatically closed 7 days after the last reply. I am a student implementing stack with singly linked list using C, following a book called Fundamentals of Data Structures in C.. Using Kolmogorov complexity to measure difficulty of problems? . - the incident has nothing to do with me; can I use this this way? And fwstr > is dereferenced in the following codes. 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. Minimising the environmental effects of my dyson brain. This is indeed an obvious False Positive from the rule. The 2nd NCCE/CS pair seems redundant with the first NCCE/CS pair. Is it possible to create a concave light? LANG.MEM.NPDLANG.STRUCT.NTADLANG.STRUCT.UPD, Null pointer dereferenceNull test after dereferenceUnchecked parameter dereference, Can detect violations of this rule. Not the answer you're looking for? context.RaiseException . To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Is a PhD visitor considered as a visiting scholar? Also, the term 'pointer' is bad (but maybe it comes from the FindBugs tool): Java doesn't have pointers, it has references. Reports. If you try to access any member variables or methods with that variable, you are trying to dereference it.
