which would allow us to systematically observe what you are having. Obviously the value of that pointer could have changed since the . And the semantics, as I said, are different. New replies are no longer allowed. 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. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Since you cannot have a variable of type void, the pointer will not point to any data and therefore cannot be dereferenced. > Further, if kstrdup() returns NULL, we should return ERR_PTR(-ENOMEM) to > the caller site. Void pointers cannot be dereferenced as any other pointer. NullPointerException is thrown when program attempts to use an object reference that has the null value. We really appreciate your help. I think "res.getBody() == null" checks null first so it should go to return line, not reach to next if condition. Correct; a null pointer is not a valid pointer for the C library functions. ssize_t (*aio_read)(struct kiocb *, char __user *, size_t . the Java one). In this case, the difference is the assumption thatmalloc() always returns non-nullfor the second NCCE, whereas the first NCCE has themalloc() abstracted away. It is useful to have a function with portable interface but platform-dependent implementation: extern bool invalid(const void *); Please explain: Without this, we wont be able to help you. C static code analysis: Null pointers should not be dereferenced C static code analysis Unique rules to find Bugs, Vulnerabilities, Security Hotspots, and Code Smells in your C code All rules 311 Vulnerability 13 Bug 74 Security Hotspot 18 Code Smell 206 Quick Fix 14 Tags "memset" should not be used to delete sensitive data Vulnerability Thanks for the feedback. If not, this might be a bug. Just because something is a pointer does not mean you should call delete . 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. This rule applies to all null pointers, regardless of which function returned them. How to use Slater Type Orbitals as a basis functions in matrix method correctly? 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. But the problem also exists in the compliant version, so I'm not so sure that it's really compliant. Using Kolmogorov complexity to measure difficulty of problems? What is a serialVersionUID and why should I use it? (C11, S7.24.2.1). 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. Which ensures that the chunkdata pointer is valid, but makes no such check to the user_data pointer. Software project. name result . Clearly the standard enumerates 1 case of undefined behavior, but makes no special mention of n=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. When c_str is dereferenced in memcpy(), the program exhibits undefined behavior. Cause we need throw our own Runtime Exception, well-known methods wont help. This sounds indeed like a bug in the flow when an exception is raised. In this noncompliant code example, input_str is copied into dynamically allocated memory referenced by c_str. To be precise, once length is changed to a size_t and cannot take negative values, it cannot have an invalid value. Java Specification Participation Agreement version in use: 2.0. 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 think that checking for user_data being NULL would be an improvement to the CS so long as there is an explicit mention that user_data being NULL is invalid even if length == 0. Asking for help, clarification, or responding to other answers. Sonar detects that res.getBody() can be null when you do the check res.getBody()==null. The return value from strchr() is often NULL, but the dev might know that a specific strchr() function call will not return NULL. Consider the following scenario: you are asked to create a Java class MetaDisplay that contains a static void printTable(String r) method. How handle the initialization of "responseDto" without "null" because is throwing the issue on sonar. Im having trouble understanding your problem. Removing the check "exception != null" raises S2259 "Null pointers should not be dereferenced" on "throw exception". It also uses the unsigned type size_t to pass the length parameter, ensuring that negative values are not passed to func(). 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. Passing a null pointer tomemcpy() would produce undefined behavior, even if the number of bytes to copy were 0. In C, dereferencing a null pointer is undefined behavior. If malloc() fails, it returns a null pointer that is assigned to c_str. Automated Detection Null pointer dereferences can happen in path-dependent ways. But no where in that particular idiom would a NULL pointer necessarily be deferenced. Maybe one of these methods is already doing what your methods is doing, and could be considered as replacement. We seem to have a false positive for "Null pointers should not be dereferenced" - squid:S2259. All rights are expressly reserved. Pittsburgh, PA 15213-2612
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. Thanks, David! positive S2637 in SonarQube 6.7.1 LTS, SonarQube for MSBuild not reporting quality issues, getTextContent() through "Null pointers should not be dereferenced". After that, you call res.getBody() again. It's a modular system with the . A common memory-leak idiom, is reallocating storage and assigning its address to a pointer that already points to allocated storage. If you try to access any member variables or methods with that variable, you are trying to dereference it. 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 Seems the analizer don't recognice the logic with the funcional object Optional. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. The solution that I recommend is not work with null returns or variables on Java, try to avoid it. IDE extension that lets you fix coding issues before they exist! 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). Additionally, if input_str is a null pointer, the call to strlen() dereferences a null pointer, also resulting in undefined behavior. Why does the second compliant example permit using possibly-null pointers? 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. )}"); 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. can have the value zero on a call to that function. which version of SonarQube are you using? 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. I reordered that code example to do all the checks before allocations. Your assertion is not backed by the wording in the standard, nor by common implementer understanding. LANG.MEM.NPDLANG.STRUCT.NTADLANG.STRUCT.UPD, Null pointer dereferenceNull test after dereferenceUnchecked parameter dereference, Can detect violations of this rule. Connect and share knowledge within a single location that is structured and easy to search. How can I check before my flight that the cloud separation requirements in VFR flight rules are met? On many platforms, dereferencing a null pointer results inabnormal program termination, but this is not required by the standard. In the first compliant example it's useless to do allocation if the essential pointer user_data is NULL. The libpng library allows applications to read, create, and manipulate PNG (Portable Network Graphics) raster image files. That interpretation of the standard is not supported universally. All content is copyright protected. Passing ownership of something also requires pointers. 4. MSBuild SonarQube Runner Resharper Plugin receives skipping info errors File not in sonarqube, SonarQube jenkins plugin returns "Server returned HTTP response code: -1, message: 'null' for URL: https://api.github.com/user", SonarQube: Ignore issues in blocks not working with regex, sonarLint complains "Null pointers should not be dereferenced (squid:S2259)" despite that possibility being handled, Java: (false?) Not the answer you're looking for? However, memory allocation > functions such as kstrdup() may fail and returns NULL. The result of calling such a helper function should be . I suppose we can check that that is not null, but we cannot check that it is valid (in any portable way). Your code needs to do something about the possible NullPointerException when some exception is caught, because in this scenario the responseDto will be null. 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. Im very new to sonar, is there a way to add methods to the whitelist? 1 Null pointers should not be dereferenced @CheckForNull String getName(){.} Find centralized, trusted content and collaborate around the technologies you use most. Are there tables of wastage rates for different fruit and veg? My code is GPL licensed, can I issue a license to have my code be distributed in a specific MIT licensed 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. Here is our source code: Sign in to download full-size image res.getBody() == null || res.getBody().getServiceResult() == null). Dereferencing a null pointer is undefined behavior, typically abnormal program termination. What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? 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. 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. Find centralized, trusted content and collaborate around the technologies you use most. util.regex.Matcher, java - Swing .getParent() . In my experience, there are reasons to check for a NULL pointer other than dereferencing it. sonarlint complains that PS: I also tried the code in android studio which uses Lint and got no warnings. What sort of strategies would a medieval military use against a fantasy giant? Small typo nit: "such as if i t pointed to freed memory" meant to say "if it" instead (removing whitespace). isEmpty(Collection collection) Please direct comments on this JSR to the Spec Lead (s) Team. Interactions/interfaces with C can't use references. Explain about call by reference with an . 11 Sep, 2006. 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. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. To create a custom null validation method declare an attribute with name ValidatedNotNullAttribute and mark the parameter that is (in the meantime, in case of any other false-positive suspicion, make sure to check those latest versions as bunch of improvements are regularly released). Haiku is a free and open-source operating system for PC designed to be binary compatible with the BeOS operating system and embodying the basic ideas of BeOS. (I think you cover that in a different rule.) By explicitly teaching the C++ standard class behaviors we can make the Analyzer to find more bugs related to modern C++ code. ability to run any cleanup processes. Whats the grammar of "For those whose stories they are"? Trying to understand how to get this basic Fourier Series. This topic was automatically closed 7 days after the last reply. The test was added to catch the possibly theoretical situation where the length of input_str was somehow the maximum size for size_t, and adding one to this size in the malloc expression (to allocated space for the trailing null byte) results in an integer overflow. In some situations, however, dereferencing a null pointer can lead to the execution of arbitrary code [Jack 2007,van Sprundel 2006]. You're in a company-managed project. sonarqube Report False-positive / False-negative [LTS] The new SonarQube LTS is here: SONARQUBE 9.9 LTS, SonarQube - Null Pointer Dereference Issue. . Believing that dereferencing NULL shouldn't crash the system doesn't make it true. What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? [4] Agreed. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. I believe in this case, either expression would work.