In the code, we check the not nullity with java.util.Objects.nonNull(). That is only true if possibleNumbers contains no element.. BTW: none of these warnings are shown by . My below code where I'm calling a stored procedure is giving a null pointer exception. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Please direct comments on this JSR to the Spec Lead (s) Team. There are other problems with this code, as is noted in the rule. Small typo nit: "such as if i t pointed to freed memory" meant to say "if it" instead (removing whitespace). I think "res.getBody() == null" checks null first so it should go to return line, not reach to next if condition. 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. Null pointer should not be dereferenced , Sonar detects that res.getBody() can be null when you do the check res.getBody()==null. ability to run any cleanup processes. Things go fine now. The expected result here is solve the issue with sonarqube. So no checking of the length is necessary (besides preventing integer overflow, which the compliant solution does). To learn more, see our tips on writing great answers. Made code more compliant with other rules. [4] 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. LANG.MEM.NPDLANG.STRUCT.NTADLANG.STRUCT.UPD, Null pointer dereferenceNull test after dereferenceUnchecked parameter dereference, Can detect violations of this rule. 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. Issues Components. 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. Now (sonarqube java analyzer version 4.3.0.7717) it's supported and works fine. ), 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). It is still a pointer though, to use it you just have to cast it to another kind of pointer first. Should trycatch go inside or outside a loop? validated for null in your method declaration with it: 2008-2023 SonarSource S.A., Switzerland. Even if the object is null in this case, it will not give an exception and will print ' null ' to the output stream. {"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. Discover SonarLint SaaS Setup is effortless and analysis is automatic for most languages Discover SonarCloud Self-Hosted Fast, accurate analysis; enterprise scalability Discover SonarQube Secrets ABAP 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. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. In the first compliant example it's useless to do allocation if the essential pointer user_data is NULL. . 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. null(java.lang.NullPointerException) . This sounds indeed like a bug in the flow when an exception is raised. On many platforms, dereferencing a null pointer results inabnormal program termination, but this is not required by the standard. The only potential null is the return value of list(). Please explain: Without this, we wont be able to help you. How do I align things in the following tabular environment? This sounds indeed like a bug in the flow when an exception is raised. At worst, it could expose debugging information that would be useful to an attacker, or it could allow an attacker to bypass security measures. Is it possible to rotate a window 90 degrees if it has the same length and width? Privacy Policy, Detect issues in your GitHub, Azure DevOps Services, Bitbucket Cloud, GitLab repositories. False-positives are pointed out in other SO posts (1 & 2), where nulls are involved across functions and procedures. Identify where the allocation occurs. , NPE : null-, . Trying to understand how to get this basic Fourier Series. I suppose there is a question of "Is a pointer that points to 0 bytes valid?" Its purpose is to serve as a special value for a pointer that could indicate a special condition in your program. On many platforms, dereferencing a null pointer results in abnormal program termination, but this is not required by the standard. Not the answer you're looking for? NullPointerException is a RuntimeException. Doing so will cause a NullPointerException to be thrown. That is, sets equivalent to a proper subset via an all-structure-preserving bijection. To learn more, see our tips on writing great answers. 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). 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. 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 . In the meantime, Im locking this thread. I have a sonar alert on this call minRating.getRatgCaam(). This topic was automatically closed 7 days after the last reply. I reordered that code example to do all the checks before allocations. How do I align things in the following tabular environment? Cause we need throw our own Runtime Exception, well-known methods wont help. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. in above code, Optimizers are optimizing based on this latitude and have been for years. It looks like a logic bug, which can cause a memory leaking. This cross-file approach analysis can be quite resource-consuming, and we are not ready to openly enable the feature. Software Engineering Institute util.regex.Matcher, java - Swing .getParent() . Java Specification Participation Agreement version in use: 2.0. 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 How do you ensure that a red herring doesn't violate Chekhov's gun? 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. 1 Null pointers should not be dereferenced @CheckForNull String getName(){.} int changed to size_t and if size_t parameter's is zero, allocate one word. best, such an exception will cause abrupt program termination. ), 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. Why is there a voltage on my HDMI and coaxial cables? Thanks for the feedback. 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. Alternate Terms Relationships I've changed it to say null pointer instead of invalid pointer. How can we prove that the supernatural or paranormal doesn't exist? Provide a self-contained reproducer (zipped project?) 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. Agreed. http://blog.llvm.org/2011/05/what-every-c-programmer-should-know_14.html. the Java one). That's true. 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). Maybe one of these methods is already doing what your methods is doing, and could be considered as replacement. Ah, gotcha. isEmpty(Map map) IMHO, the rule title should be changed to something less general. This issues is displayed by SonarQube. . Find centralized, trusted content and collaborate around the technologies you use most. 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 method isNR(minRating) is a helper method that validate among other things, if the object minRating is null. Which ensures that the chunkdata pointer is valid, but makes no such check to the user_data pointer. , . 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. Using Kolmogorov complexity to measure difficulty of problems? 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(). 3.Null pointers should not be derefer enced/accessed. // <------- 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. If you preorder a special airline meal (e.g. In C, dereferencing a null pointer is undefined behavior. If you try to access any member variables or methods with that variable, you are trying to dereference it. Unfortunately, its actual state also has some limitations, like the one you are hitting here. Explain about call by reference with an . These can be: Invoking a method from a null object. Aaron:I suspect we are talking past each other. 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. Making statements based on opinion; back them up with references or personal experience. We can see that at obj.run(), obj can not be null, but is pointed out by Sonar. Using platform-specific means (e.g. A common memory-leak idiom, is reallocating storage and assigning its address to a pointer that already points to allocated storage. SONAR, SONARSOURCE, SONARLINT, SONARQUBE and SONARCLOUD are trademarks of SonarSource S.A. All other trademarks and copyrights are the property of their respective owners. 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. 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. uninitialized reference-type class members. 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>. Recovering from a blunder I made while emailing a professor. I am a student implementing stack with singly linked list using C, following a book called Fundamentals of Data Structures in C.. How to use java.net.URLConnection to fire and handle HTTP requests, Why should Java 8's Optional not be used in arguments, sonarLint complains "Null pointers should not be dereferenced (squid:S2259)" despite that possibility being handled. Thered be huge value in jumping onto the latest version of the ecosystem (notably SonarQube), and benefit from all latest analyzers (e.g. () New replies are no longer allowed. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. How can we let this pass? Search for vulnerabilities resulting from the violation of this rule on the CERT website. I suggest that this topic needs to include calloc() and realloc() Refer to Linux man pages online for more enlightenment about malloc(), and friends. Is there a proper earth ground point in this switch box? . Thanks for your relpy. Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2, Sonar false-positive on rule: Null pointers should not be dereferenced, Null Pointer Dereference issue not detected when the pointer is returned by another function. - the incident has nothing to do with me; can I use this this way? 1 Answer Sorted by: 1 Your code is ok. Is it suspicious or odd to stand by the gate of a GA airport watching the planes? SonarLint: A "NullPointerException" could be thrown; "getBody()" can return null. 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. raiseException() return, Sonar Many platforms can support testing for those also. Software project. 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. IDE extension that lets you fix coding issues before they exist! Which @NotNull Java annotation should I use? Isn't easier just to check valid range of length? , RemoteContext new ExceptionType() RemoteContext , SonarLintJava (), java - sonarLint "Null pointers should not be dereferenced (squid:S2259)"Stack Overflow 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 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. (In contrast, the case of passing 0 bytes to malloc is addressed in C11.) Sonar is ok. Sonar can't determine that the helper method did the null validation. 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. Thus we should check > this kstrdup() operation. That is why I explicitly check for this in my attempted solution. Perhaps this could be done with a special constraint that will notify the SE engine that we learned from a Debug.Assert call. How do you ensure that a red herring doesn't violate Chekhov's gun? We. Is it possible to create a concave light? 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.. When and how should I use a ThreadLocal variable? "After the incident", I started to be more careful not to trip over things. 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". This rule applies to all null pointers, regardless of which function returned them. 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. IDE extension that lets you fix coding issues before they exist! The null concept refers to the idea that a pointer can hold a special value that is not equal to another pointer. Unlike reference types, pointer types are not tracked by the default garbage . 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. Then the reading of the buffer via bstr_printf() will then look at the pointer to process the final output. 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. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. All content is copyright protected. 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. Why are physically impossible and logically impossible concepts considered separate in terms of probability? Is null check needed before calling instanceof? When B is null, The control reaches inside the main if block only when length of A is 1. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. 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. And the semantics, as I said, are different. Not the answer you're looking for? If you write [ref], then a null pointer is not allowed, but if you write [unique], then a null pointer is permitted. 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. How to tell which packages are held back due to phased updates. The article easily misleads the reader into believeing that ensuring pointer validity boils down to checking for pointer being not equal to NULL. https://www.yammer.com/ http://feeds.feedburner.com/office/fmNx Just because something is a pointer does not mean you should call delete . I'd guess WG14 has considered these questions, but I haven't until now :). By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. This is a matter of style, and also following code walkthrough. Null pointers should not be dereferenced. it could allow an attacker to bypass security measures. It does not point to any area of memory. 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 At worst, it could expose debugging information that would be useful to an attacker, or it could allow an attacker to . - the incident has nothing to do with me; can I use this this way? This compliant solution eliminates the null pointer deference by initializing sk to tun->sk following the null pointer check. There are many ways to resolve this. This is indeed a false positive because, at time of writing, the sonarqube java analyzer (version 4.2.1 at time of writing) does not support cross procedural analysis and so it is not able to determine that indeed, for the condition to be true, the value of minRating has to be non null. A reference to null should never be dereferenced/accessed. Some Interesting Facts: 1) void pointers cannot be dereferenced. When you have a variable of non-primitive type, it is a reference to an object. 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. A pointer to null (the 0 memory address) should never be dereferenced/accessed. 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. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Dereferencing > this null pointer may cause the kernel go wrong. One could argue that all code examples would be redundant with the first pair. Basically, yes. So we have to check all the arguments before performing any actions. sonarqube The issue arises when dereferenced pointers are used. Also, the term 'pointer' is bad (but maybe it comes from the FindBugs tool): Java doesn't have pointers, it has references. Sonar is ok. This code also violates ERR33-C. Detect and handle standard library errors. In my experience, there are reasons to check for a NULL pointer other than dereferencing it. res.getBody() == null || res.getBody().getServiceResult() == null). "After the incident", I started to be more careful not to trip over things. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Im very new to sonar, is there a way to add methods to the whitelist? Appropriate typecasting is necessary. Extended Description NULL pointer dereference issues can occur through a number of flaws, including race conditions, and simple programming omissions. In the simplest case, this function just returns the result of calling kmalloc. PS: I also tried the code in android studio which uses Lint and got no warnings. In the complaint version, I like to make source code checking a little quicker by putting parenthesizes around arguments to |= or &= as. Is there a single-word adjective for "having exceptionally strong moral principles"? A reference to null should never be dereferenced/accessed. Just a few words about the rule now. Making statements based on opinion; back them up with references or personal experience. sonarLint (3.2.) The same problem we will have with "Add at least one assertion to this test case." NULL vs Uninitialized pointer - An uninitialized pointer stores an undefined value. The SonarJava SE engine is however, by default, not configured to explore methods declared in other files (in your case, your utility class CheckUtils). ", 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". If copying takes place between objects that overlap, the behavior is undefined. Connect and share knowledge within a single location that is structured and easy to search. This is indeed an obvious False Positive from the rule. name result . 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. Check whether a String is not Null and not Empty. The indicated severity is for this more severe case; on platforms where it is not possible to exploit a null pointer dereference to execute arbitrary code, the actual severity is low. Is a PhD visitor considered as a visiting scholar? positive S2637 in SonarQube 6.7.1 LTS, SonarQube for MSBuild not reporting quality issues, getTextContent() through "Null pointers should not be dereferenced". 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). The fact that you can't pass a null (no object) with a reference parameter can be a reason to use a pointer instead. Carnegie Mellon University In the case of the ARM and XScale architectures, the 0x0 address is mapped in memory and serves as the exception vector table; consequently, dereferencing 0x0 did not cause an abnormal program termination. Trying to understand how to get this basic Fourier Series. When c_str is dereferenced in memcpy(), the program exhibits undefined behavior. Pittsburgh, PA 15213-2612 I believe in this case, either expression would work. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, SonarQube null pointers should not be dereferenced on try/catch, How Intuit democratizes AI development across teams through reusability. SONAR, SONARSOURCE, SONARLINT, SONARQUBE and SONARCLOUD are trademarks of SonarSource S.A. All other trademarks and copyrights are the property of their respective owners. Thank you for clarifying your assertion until I understood it properly. Is the God of a monotheism necessarily omnipotent? 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. Are there tables of wastage rates for different fruit and veg? We seem to have a false positive for "Null pointers should not be dereferenced" - squid:S2259. Thanks for contributing an answer to Stack Overflow! Connect and share knowledge within a single location that is structured and easy to search. SonarJava. So, this code should address the Sonar problem: You can also eliminate the null check using Optional>, like: Even I don't recommend this, you can just check the null responseDto without any use of Optional: Thanks for contributing an answer to Stack Overflow! Since SIZE_MAX represents the largest possible object, the largest possible string would then be SIZE_MAX-1 characters long (excluding '\0'). Issues Components. ii. }. java Automated Detection Null pointer dereferences can happen in path-dependent ways. Dereferencing a null pointer is undefined behavior, typically abnormal program termination. My question is; is my solution incorrect? 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. 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" 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. We can not disable any rule, sonar do validation in "Sonar way" (actual name of profile :) ), so we will need to mark them "Wont fix" each time it appear again in new code.
Tropicalia 2021 Lineup, Binkley's Funeral Home Obituaries, Articles N