Share Improve this answer Follow answered Oct 5, 2017 at 16:27 The 2nd NCCE/CS pair seems redundant with the first NCCE/CS pair. 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. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. You're in a company-managed project. Even if the object is null in this case, it will not give an exception and will print ' null ' to the output stream. Is null check needed before calling instanceof? What is generic pointer? Asking for help, clarification, or responding to other answers. attacker to bypass security measures. Also, the term 'pointer' is bad (but maybe it comes from the FindBugs tool): Java doesn't have pointers, it has references. Find null smart pointer dereferences with the Clang Static Analyzer 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 . context.RaiseException , (/) 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). Asking for help, clarification, or responding to other answers. (In contrast, the case of passing 0 bytes to malloc is addressed in C11.) On many platforms, dereferencing a null pointer results in abnormal program termination, but this is not required by the standard. This solution also ensures that theuser_data pointer is not null. There are other problems with this code, as is noted in the rule. A reference to null should never be dereferenced/accessed. 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. 11 Sep, 2006. Connect and share knowledge within a single location that is structured and easy to search. New replies are no longer allowed. Seems the analizer don't recognice the logic with the funcional object Optional. I added an assertion to that compliant code example. Does Java have support for multiline strings? name result . Please direct comments on this JSR to the Spec Lead (s) Team. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. You can compare a pointer with NULL to test for the special condition. 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. This code also violates ERR33-C. Detect and handle standard library errors. When and how should I use a ThreadLocal variable? isEmpty(Map map) Thanks, David! What can a lawyer do if the client wants him to be acquitted of everything despite serious evidence? Good question! 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 */ What is pointed to should only be deleted if it was created with new. Java Specification Participation Agreement version in use: 2.0. Sonar false-positive on rule: Null pointers should not be dereferenced It could be non-null the first time but not the second time, sonar does not know this. Null pointer - Wikipedia Write a semantic patch to nd cases where the result of calling kmalloc is dereferenced with no previous NULL pointer test. IDE extension that lets you fix coding issues before they exist! What does it mean that a reference must refer to an object, not a dereferenced null pointer? In C, dereferencing a null pointer is undefined behavior. Obviously the value of that pointer could have changed since the . Making statements based on opinion; back them up with references or personal experience. 2008-2023 SonarSource S.A., Switzerland. At worst, it could expose debugging information that would be useful to an attacker, or How can I check before my flight that the cloud separation requirements in VFR flight rules are met? Mutually exclusive execution using std::atomic? That noncompliant code example (it's currently the 3rd) came from the Linux kernel, whose source is publicly available. 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. NULL POINTERS SHOULD NOT BE DEREFERENCED - jobhuntley.com It is still a pointer though, to use it you just have to cast it to another kind of pointer first. 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. 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. Believing that dereferencing NULL shouldn't crash the system doesn't make it true. That makes sense. Essentially, this code and the previous dereference disagree as to whether this value is allowed to be null. What methods/tools can be used to determine the cause so that you stop the exception from causing the progra. Powered by Discourse, best viewed with JavaScript enabled. And the compliant solution guarantees that the pointer will be valid if the code calls memcpy(). I am a student implementing stack with singly linked list using C, following a book called Fundamentals of Data Structures in C.. So the SIZE_MAX check was unnecessary. 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. Pittsburgh, PA 15213-2612 res.getBody() == null || res.getBody().getServiceResult() == null). 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. Since you cannot have a variable of type void, the pointer will not point to any data and therefore cannot be dereferenced. SonarJava Version 5.9.2 (build 16552). Status: Dormant. 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>. [4] Why does Mister Mxyzptlk need to have a weakness in the comics? Trying to understand how to get this basic Fourier Series. Not the answer you're looking for? When should pointers be checked for NULL in C? 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. Removing the check "exception != null" raises S2259 "Null pointers should not be dereferenced" on "throw exception". I feel my situation is not as complicated. The solution that I recommend is not work with null returns or variables on Java, try to avoid it. Which version of SonarJava plugin do you have? positive S2637 in SonarQube 6.7.1 LTS, Sonar false positive, "change condition so that it does not always evaluate to true. The expected result here is solve the issue with sonarqube. 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. Explain about call by reference with an . It's a modular system with the . [PATCH] drm_edid-load: Fix a missing-check bug in drivers/gpu/drm/drm It's still illegal. Ticket opened : Thanks a lot for the minimalized reproducer ! EXP01-J. Do not use a null in a case where an object is required isEmpty(Collection collection) A pointer to null (the 0 memory address) should never be dereferenced/accessed. assert(!invalid(p)); // or whatever, bool invalid(const void *p) { Just a few words about the rule now. SonarJava. 4500 Fifth Avenue This is a feature that we are currently heavily working on to be able to switch off such kind of false positives. 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. 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.) It does not point to any area of memory. The solution that I recommend is not work with null returns or variables on Java, try to avoid it. [PATCH 1/3] usb: ucsi: Fix NULL pointer deref in ucsi_connector_change() 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. This sounds indeed like a bug in the flow when an exception is raised. 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]. Avoid Returning null from Methods. Sonar violation: Null pointers should not be dereferenced #7459 - GitHub EXP34-C is a common consequence of ignoring function return values, but it is a distinct error, and can occur in other scenarios too. 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. How to use Slater Type Orbitals as a basis functions in matrix method correctly? PDF Fourth Coccinelle Workshop { Exercises @Tibor SonarQube version 5.6.6, IntelliJ SonarLint plugin 3.0.0.2041, Sonar: Null pointers should not be dereferenced, How Intuit democratizes AI development across teams through reusability. Analysis of Haiku Operating System (BeOS Family) by PVS-Studio. Part 1 In particular, ROSE ensures that any pointer returned by malloc(), calloc(), or realloc() is first checked for NULL before being used (otherwise, it is free()-ed). CWE - CWE-476: NULL Pointer Dereference (4.10) - Mitre Corporation At worst, it could expose debugging information that would be useful to an attacker or it could allow an The issue arises when dereferenced pointers are used. That is only true if possibleNumbers contains no element.. BTW: none of these warnings are shown by . Note that it doesn't know how to check for non-heap, non-stack. Thanks for the feedback. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. . Why are Suriname, Belize, and Guinea-Bissau classified as "Small Island Developing States"? io.NotSerializableException : java. When B is null, The control reaches inside the main if block only when length of A is 1. sonarlint complains that You need to benchmark. strongSwan - strongSwan Vulnerability (CVE-2023-26463) Find centralized, trusted content and collaborate around the technologies you use most. S2259: Null pointers should not be dereferenced - Sonar Community 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. return p == NULL || (char *)p < &_etext; The libpng library implements its own wrapper to malloc() that returns a null pointer on error or on being passed a 0-byte-length argument. 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).