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. 2008-2023 SonarSource S.A., Switzerland. It does not point to any area of memory. When and how should I use a ThreadLocal variable? You need to benchmark. Linear regulator thermal information missing in datasheet, Identify those arcade games from a 1983 Brazilian music video. Recovering from a blunder I made while emailing a professor. What methods/tools can be used to determine the cause so that you stop the exception from causing the progra. HTTP request redirections should not be open to forging attacks Deserialization should not be vulnerable to injection attacks Endpoints should not be vulnerable to reflected cross-site scripting (XSS) attacks "CoSetProxyBlanket" and "CoInitializeSecurity" should not be used Database queries should not be vulnerable to injection attacks 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. Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2. The standard will simply copy 0 byteswhich is essentially a no-op. Why does Mister Mxyzptlk need to have a weakness in the comics? An awesome tip to avoid NPE is to return empty strings or empty collections rather than null. Calls to extension methods are not reported because they can still operate on null values. How can we prove that the supernatural or paranormal doesn't exist? 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. sonarLint (3.2.) 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". Depending on whether the pointer is valid (i.e. If copying takes place between objects that overlap, the behavior is undefined. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. to 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. Sonar is ok. sonarlint complains that Is it plausible for constructed languages to be used to affect thought and control or mold people towards desired outcomes? How do I align things in the following tabular environment? JCP version in use: 2.6. A pointer is simply a variable that contains a memory address. Please direct comments on this JSR to the Spec Lead (s) Team. We resolved it by adding our tools path in the white list, and repackaging it. Believing that dereferencing NULL shouldn't crash the system doesn't make it true. A NULL pointer can be dereferenced when signatures are being verified on PKCS7 signed or signedAndEnveloped data. 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). When a variable is declared as being a pointer to type void, it is known as a generic pointer. Find centralized, trusted content and collaborate around the technologies you use most. 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 feel my situation is not as complicated. As for copy vs pointer/reference - it depends. The issue arises when dereferenced pointers are used. I reordered that code example to do all the checks before allocations. In this case, the difference is the assumption thatmalloc() always returns non-nullfor the second NCCE, whereas the first NCCE has themalloc() abstracted away. What does it mean that a reference must refer to an object, not a dereferenced null pointer? Setup is effortless and analysis is automatic for most languages, Fast, accurate analysis; enterprise scalability. It also reinforces the notion to the reader that any time you see arithmetic in an allocation expression, you need to think about corner-cases. Is there a proper earth ground point in this switch box? ncdu: What's going on with this second size column? That is, sets equivalent to a proper subset via an all-structure-preserving bijection. Minimising the environmental effects of my dyson brain. Are there tables of wastage rates for different fruit and veg? 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. 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. 5.2 Part 2 Sometimes a helper function is de ned to perform the memory allocation. Is there a proper earth ground point in this switch box? 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. 1 Answer Sorted by: 1 Your code is ok. This sounds indeed like a bug in the flow when an exception is raised. Is the God of a monotheism necessarily omnipotent? Which @NotNull Java annotation should I use? Appropriate typecasting is necessary. Why are Suriname, Belize, and Guinea-Bissau classified as "Small Island Developing States"? When c_str is dereferenced in memcpy(), the program exhibits undefined behavior. It is useful to have a function with portable interface but platform-dependent implementation: extern bool invalid(const void *); http://blog.llvm.org/2011/05/what-every-c-programmer-should-know_14.html. Shouldn't the function check all pointers before dereferencing them or passing them to another function? very old code or C code being worked into c++ may have functions that expect the user to delete the data. Just because something is a pointer does not mean you should call delete . Optimizers are optimizing based on this latitude and have been for years. Privacy Policy, Detect issues in your GitHub, Azure DevOps Services, Bitbucket Cloud, GitLab repositories. 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.. Two null pointers will always be equal to each other. Such long getter chains can also be replaced with Optional + map + ifPresent lambda style. 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]. 4500 Fifth Avenue
Does Counterspell prevent from any further spells being cast on a given turn? https://www.yammer.com/ http://feeds.feedburner.com/office/fmNx 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. rev2023.3.3.43278. Not the answer you're looking for? Because null pointer dereferencing is UB, the if (!tun) check can be elided entirely by the optimizer (since the tun->sk implies that tun must be non-null). public boolean isNameEmpty() { return getName().length() == 0; // Noncompliant; the result of getName() could be null, but isn't null-checked } . sonarqube I'd guess WG14 has considered these questions, but I haven't until now :). In C# and Java, all reference types can point to null. How can we let this pass? If not, this might be a bug. Setup is effortless and analysis is automatic for most languages, Fast, accurate analysis; enterprise scalability. Does Java have support for multiline strings? If the project is not compiled, and without sonar.java.binaries whether the white list takes effect? This likely means that youre on an ancient version of the Java analyzer. attacker to bypass security measures. Put a new ResponseEntity is wrong because I won't know what will be the answer for the status of http. This cross-file approach analysis can be quite resource-consuming, and we are not ready to openly enable the feature. name result . The user_data pointer could be invalid in other ways, such as pointing to freed memory. You can use Optional instead. This rule applies to all null pointers, regardless of which function returned 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. Void pointers cannot be dereferenced as any other pointer. which version of SonarQube are you using? Connect and share knowledge within a single location that is structured and easy to search. You're in a company-managed project. - the incident has nothing to do with me; can I use this this way? Unlike reference types, pointer types are not tracked by the default garbage . All rights are expressly reserved. 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 */ False-positives are pointed out in other SO posts (1 & 2), where nulls are involved across functions and procedures. In the meantime, Im locking this thread. I would also guess that pointers that point to the one-past-the-end of an array are also invalid. Goal But no where in that particular idiom would a NULL pointer necessarily be deferenced. Iflengthhas the value1, the addition yields 0, and png_malloc() subsequently returns a null pointer, which is assigned to chunkdata. Removing the check "exception != null" raises S2259 "Null pointers should not be dereferenced" on "throw exception". 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. )}"); Dereferencing a null pointer is undefined behavior. Check whether a String is not Null and not Empty. In C, dereferencing a null pointer is undefined behavior. It looks like a logic bug, which can cause a memory leaking. The article easily misleads the reader into believeing that ensuring pointer validity boils down to checking for pointer being not equal to NULL. The fact that you can't pass a null (no object) with a reference parameter can be a reason to use a pointer instead. Which version of SonarJava plugin do you have? Ticket opened : Thanks a lot for the minimalized reproducer ! 3.Null pointers should not be derefer enced/accessed. 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. Thered be huge value in jumping onto the latest version of the ecosystem (notably SonarQube), and benefit from all latest analyzers (e.g. In case the hash algorithm used for the signature is known to the OpenSSL library but the implementation of the hash algorithm is not available the digest initialization will fail. It also uses the unsigned type size_t to pass the length parameter, ensuring that negative values are not passed to func(). "After the incident", I started to be more careful not to trip over things. Carnegie Mellon University
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. To learn more, see our tips on writing great answers. Thanks, David! 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. How handle the initialization of "responseDto" without "null" because is throwing the issue on sonar. IDE extension that lets you fix coding issues before they exist! Privacy Policy, Detect issues in your GitHub, Azure DevOps Services, Bitbucket Cloud, GitLab repositories. In the first compliant example it's useless to do allocation if the essential pointer user_data is NULL. What is a serialVersionUID and why should I use it? Why is there a voltage on my HDMI and coaxial cables? Then the reading of the buffer via bstr_printf() will then look at the pointer to process the final output. So no checking of the length is necessary (besides preventing integer overflow, which the compliant solution does). But when length of A is 1, the control never reaches the else block. We. 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. When B is null, The control reaches inside the main if block only when length of A is 1. With their flexibility, void pointers also bring some constraints. And fwstr > is dereferenced in the following codes. https://stackoverflow.com/questions/47534436/, https://stackoverflow.com/questions/47534436/, java - Jenkins groovy : Error: java. ), 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). But even with this, the concerned object it tagged as a possible NullPointerException problem. Does it just mean failing to correctly check if a value is null? 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. The null pointer check for writing or dereferencing should be a compiler flag or library setting. assert(!invalid(p)); // or whatever, bool invalid(const void *p) { This engine is validating execution paths and checking for non-null values or null-check along the way, exploring all the possibilities.