Can I tell police to wait and call a lawyer when served with a search warrant? Depending on whether the pointer is valid (i.e. 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). You're in a company-managed project. New replies are no longer allowed. Passing ownership of something also requires pointers. Accessing or modifying a null object's field. Asking for help, clarification, or responding to other answers. that we haven't considered here: I'd guess null pointers are not valid, even though they point to 0 bytes. All rights are expressly reserved. specifies the length of the array for a function. A reference to null should never be dereferenced/accessed. Find centralized, trusted content and collaborate around the technologies you use most. 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. https://stackoverflow.com/questions/47534436/, https://stackoverflow.com/questions/47534436/, java - Jenkins groovy : Error: java. Iflengthhas the value1, the addition yields 0, and png_malloc() subsequently returns a null pointer, which is assigned to chunkdata. 3.7. If the pointer is not NULL, see if the assignment occurs only in a branch of a conditional statement.Investigate when that branch does not execute. 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. In C, dereferencing a null pointer is undefined behavior. Privacy Policy, Detect issues in your GitHub, Azure DevOps Services, Bitbucket Cloud, GitLab repositories. 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. 2008-2023 SonarSource S.A., Switzerland. 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. But what exactly does it mean to "dereference a null pointer"? 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. return p == NULL || (char *)p < &_etext; Carnegie Mellon University
How can we prove that the supernatural or paranormal doesn't exist? In the code, we check the not nullity with java.util.Objects.nonNull(). 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. 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 My below code where I'm calling a stored procedure is giving a null pointer exception. 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. Why is there a voltage on my HDMI and coaxial cables? sonar-java. All rights are expressly reserved. which version of SonarQube are you using? However, memory allocation > functions such as kstrdup() may fail and returns NULL. What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? 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. It looks like a logic bug, which can cause a memory leaking. Is there a proper earth ground point in this switch box? 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 You need to benchmark. How to use Slater Type Orbitals as a basis functions in matrix method correctly? That noncompliant code example (it's currently the 3rd) came from the Linux kernel, whose source is publicly available. Coverity Prevent cannot discover all violations of this rule, so further verification is necessary, Detects when NULL is dereferenced (Array of pointers is not checked. Unfortunately, its actual state also has some limitations, like the one you are hitting here. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. public boolean isNameEmpty() { return getName().length() == 0; // Noncompliant; the result of getName() could be null, but isn't null-checked } . Issues Components. sonarqube Batch split images vertically in half, sequentially numbering the output files, Difficulties with estimation of epsilon-delta limit proof, Minimising the environmental effects of my dyson brain. One could argue that all code examples would be redundant with the first pair. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Using platform-specific means (e.g. vegan) just to try it, does this inconvenience the caterers and staff? 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. Thanks, David! 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! 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?) Even if the object is null in this case, it will not give an exception and will print ' null ' to the output stream. SonarJava. Shouldn't the function check all pointers before dereferencing them or passing them to another function? In Java, a special null value can be assigned to an object reference. Making statements based on opinion; back them up with references or personal experience. isEmpty(Collection> collection) Java Specification Participation Agreement version in use: 2.0. I have a sonar alert on this call minRating.getRatgCaam(). parsing /proc/self/maps under linux) one might find out whether the pointer points into mapped memory, but this is still not a guarantee of validity because it is very coarse-grained see again the above example. rev2023.3.3.43278. When I added the not null validation as sonar suggest. This code also violates ERR33-C. Detect and handle standard library errors. The correct idiom is to only allocate storage if the pointer is currently 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). 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. 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. These can be: Invoking a method from a null object. At best, such an exception will cause abrupt program termination. Which ensures that the chunkdata pointer is valid, but makes no such check to the user_data pointer. Interactions/interfaces with C can't use references. What does it mean that a reference must refer to an object, not a dereferenced null pointer? 1 Answer Sorted by: 2 Your code needs to do something about the possible NullPointerException when some exception is caught, because in this scenario the responseDto will be null. Null pointer should not be dereferenced . Alternate Terms Relationships Such long getter chains can also be replaced with Optional + map + ifPresent lambda style. 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. IMHO, the rule title should be changed to something less general. 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. 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. ), 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). 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). That is why I explicitly check for this in my attempted solution. Is it plausible for constructed languages to be used to affect thought and control or mold people towards desired outcomes? How to deal with "java.lang.OutOfMemoryError: Java heap space" error? If you call connect() function, it better do the connection, but failing simply because some ptr is NULL is not good behaviour -- failures should . Find centralized, trusted content and collaborate around the technologies you use most. At worst, it could expose debugging information that would be useful to an attacker or it could allow an Is it possible to rotate a window 90 degrees if it has the same length and width? With their flexibility, void pointers also bring some constraints. How can this new ban on drag possibly be considered constitutional? Did any DOS compatibility layers exist for any UNIX-like systems before DOS started to become outmoded? Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, It is a false positive, but it might be a good idea not to do the, Sonar false-positive on rule: Null pointers should not be dereferenced, How Intuit democratizes AI development across teams through reusability. Thered be huge value in jumping onto the latest version of the ecosystem (notably SonarQube), and benefit from all latest analyzers (e.g. It's a modular system with the . Can you please start a new thread and be more explicit about the issue you are observing. raiseException() return, Sonar 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. The null pointer check for writing or dereferencing should be a compiler flag or library setting. I suppose we can check that that is not null, but we cannot check that it is valid (in any portable way). 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. Using Kolmogorov complexity to measure difficulty of problems? It is useful to have a function with portable interface but platform-dependent implementation: extern bool invalid(const void *); Check whether a String is not Null and not Empty. Is a PhD visitor considered as a visiting scholar? Dereferencing a null pointer is undefined behavior. The article easily misleads the reader into believeing that ensuring pointer validity boils down to checking for pointer being not equal to NULL. But when length of A is 1, the control never reaches the else block. , NPE : null-, . [4] To learn more, see our tips on writing great answers. Is there a single-word adjective for "having exceptionally strong moral principles"? There can be a null pointer type for each pointer type, such as a pointer to a character or a pointer to an integer, although this is . rev2023.3.3.43278. java I added an assertion to that compliant code example. 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? To learn more, see our tips on writing great answers. Write a semantic patch to nd cases where the result of calling kmalloc is dereferenced with no previous NULL pointer test. rev2023.3.3.43278. 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. Report False-positive / False-negative [LTS] The new SonarQube LTS is here: SONARQUBE 9.9 LTS, SonarQube - Null Pointer Dereference Issue. Connect and share knowledge within a single location that is structured and easy to search. 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. What is pointed to should only be deleted if it was created with new. What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? Key here (explains table format and definitions), EXP34-C = Union( CWE-690, list) where list =. Replacing broken pins/legs on a DIP IC package, Bulk update symbol size units from mm to map units in rule-based symbology, How do you get out of a corner when plotting yourself into a corner. You're in a company-managed project. 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. sonarlint complains that Why do academics stay as adjuncts for years rather than move around? I believe in this case, either expression would work. res.getBody() == null || res.getBody().getServiceResult() == null). So you can declare a string t and then add characters to the string with a plus sign : t += 'a'; The code you are having issue with is just moving the pointer to the next character which the foreach is already doing. Is there a single-word adjective for "having exceptionally strong moral principles"? In the complaint version, I like to make source code checking a little quicker by putting parenthesizes around arguments to |= or &= as. What sort of strategies would a medieval military use against a fantasy giant? Powered by Discourse, best viewed with JavaScript enabled. Seems the analizer don't recognice the logic with the funcional object Optional. In my experience, there are reasons to check for a NULL pointer other than dereferencing it. We have a false positive with the " Null pointers should not be dereferenced -squid:S2259" rule : We have a "NullPointerException" false positive for which we do not know how to solve it. Im currently using SonarQube version 5.6.6. better way to handle this is to store the result of method invocation in a variable. {"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. 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. Software Engineering Institute
How can we prove that the supernatural or paranormal doesn't exist? versions used (SonarQube, Scanner, language analyzer) All content is copyright protected. Calls to extension methods are not reported because they can still operate on null values. What is generic pointer? This compliant solution eliminates the null pointer deference by initializing sk to tun->sk following the null pointer check. Extended Description NULL pointer dereference issues can occur through a number of flaws, including race conditions, and simple programming omissions. Find centralized, trusted content and collaborate around the technologies you use most. At worst, it could expose debugging information that would be useful to an attacker, or ii. SONAR, SONARSOURCE, SONARLINT, SONARQUBE and SONARCLOUD are trademarks of SonarSource S.A. All other trademarks and copyrights are the property of their respective owners. Off by one error: It is the third example. rev2023.3.3.43278. Find centralized, trusted content and collaborate around the technologies you use most. . It's even called out explicitly in C17 7.24.1p2: Where an argument declared as size_t n specifies the length of the array for a function, n can have the value zero on a call to that function. }. 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>. Thanks for the feedback. At this point we define size as strlen(input_str) + 1. A common memory-leak idiom, is reallocating storage and assigning its address to a pointer that already points to allocated storage. Then the reading of the buffer via bstr_printf() will then look at the pointer to process the final output. It could be non-null the first time but not the second time, sonar does not know this. PS: I also tried the code in android studio which uses Lint and got no warnings. Void pointers cannot be dereferenced as any other pointer. Batch split images vertically in half, sequentially numbering the output files, Recovering from a blunder I made while emailing a professor. Currently I'm working with SonarQube solving issues but I'm facing a trouble to how handle null pointers that shouldn't be dereferenced. Here is our source code: Sign in to download full-size image And if there is no pointer_default declaration, then the default default is ref. - the incident has nothing to do with me; can I use this this way? Reports. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. It also adds assertions to document that certain other pointers must not be null. This is a matter of style, and also following code walkthrough. This engine is validating execution paths and checking for non-null values or null-check along the way, exploring all the possibilities. uninitialized reference-type class members. At worst, it could expose debugging information that would be useful to an attacker, or it could allow an attacker to bypass security measures. Doing so will at best cause abrupt program termination, without the The purpose of a NULL pointer is not to cause a processor exception when it is dereferenced (although that is nice to have for debugging.) . By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. 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]. ", 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". Trying to understand how to get this basic Fourier Series. (from res.getBody().getServiceResult() ). 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. (C11, S7.24.2.1). which would allow us to systematically observe what you are having. Solution 1, it looks like, today's solution tomorrow's problem. Is it suspicious or odd to stand by the gate of a GA airport watching the planes? In the meantime, Im locking this thread. 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. "After the incident", I started to be more careful not to trip over things. There are many ways to resolve this. (I think you cover that in a different rule.) Setup is effortless and analysis is automatic for most languages, Fast, accurate analysis; enterprise scalability. 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. 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. 1 Null pointers should not be dereferenced @CheckForNull String getName(){.} 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.. it could allow an attacker to bypass security measures. If not, this might be a bug. We really appreciate your help. If you write [ref], then a null pointer is not allowed, but if you write [unique], then a null pointer is permitted.
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