SonarQube - Null Pointer Dereference Issue - Sonar Community As a result, this noncompliant code example is vulnerable to a null pointer dereference exploit, because null pointer dereferencing can be permitted on several platforms, for example, by using mmap(2) with the MAP_FIXED flag on Linux and Mac OS X, or by using the shmat() POSIX function with the SHM_RND flag [Liu 2009]. 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. 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. [4] CWE - CWE-476: NULL Pointer Dereference (4.10) - Mitre Corporation 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 Search for vulnerabilities resulting from the violation of this rule on the CERT website. This sounds indeed like a bug in the flow when an exception is raised. False fault 'Null pointers should not be dereferenced' using Optional )}"); This rule applies to all null pointers, regardless of which function returned them. The user_data pointer could be invalid in other ways, such as pointing to freed memory. If not, this might be a bug. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. 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?) Is there a solution to add special characters from software and how to do it, Acidity of alcohols and basicity of amines. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Rule squid:S2259 is based on a Symbolic Execution (SE) engine. ", 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". (In contrast, the case of passing 0 bytes to malloc is addressed in C11.) I would also guess that pointers that point to the one-past-the-end of an array are also invalid. how to handle Sonarlint java:S2259 (Null pointers should not be There are other problems with this code, as is noted in the rule. You need to benchmark. I suppose we can check that that is not null, but we cannot check that it is valid (in any portable way). Software project. sonar_etReines-CSDN The expected result here is solve the issue with sonarqube. NULL vs Void Pointer - Null pointer is a value, while void pointer is a type. 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. The libpng library allows applications to read, create, and manipulate PNG (Portable Network Graphics) raster image files. So Bar might not be initialized but then the last line of your example should not be evaluated in this case. At worst, it could expose debugging information that would be useful to an attacker, or it could allow an attacker to . 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. It is useful to have a function with portable interface but platform-dependent implementation: extern bool invalid(const void *); Making statements based on opinion; back them up with references or personal experience. We really appreciate your help. 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. (from res.getBody().getServiceResult() ). 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. can have the value zero on a call to that function. Please explain: Without this, we wont be able to help you. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. At worst, it could expose debugging information that would be useful to an attacker, or it could allow an attacker to bypass security measures. 1 Answer Sorted by: 1 Your code is ok. 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. Then the reading of the buffer via bstr_printf() will then look at the pointer to process the final output. 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. . Now, you can find the list of whitelisted methods here. Null pointers should not be dereferenced #1155 - GitHub , RemoteContext new ExceptionType() RemoteContext , SonarLintJava (), java - sonarLint "Null pointers should not be dereferenced (squid:S2259)"Stack Overflow The issue of passing n=0 to memcpy() is distinct from null or invalid pointers. Im very new to sonar, is there a way to add methods to the whitelist? 3.Null pointers should not be derefer enced/accessed. Which version of SonarJava plugin do you have? How do I align things in the following tabular environment? Not the answer you're looking for? Null Dereference | OWASP Foundation Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. 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. U1 merged - It is a great text book for learning about linux devices. I added an assertion to that compliant code example. 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. I suggest that this topic needs to include calloc() and realloc() Refer to Linux man pages online for more enlightenment about malloc(), and friends. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. void *pointerVariableName = NULL; Since they are very general in nature, they are also known as generic pointers. The value 0 for the number of bytes to copy is not what causes the UB, it's the null pointer value which triggers it. Since you cannot have a variable of type void, the pointer will not point to any data and therefore cannot be dereferenced. That's true. 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]. How do you ensure that a red herring doesn't violate Chekhov's gun? Hi @Michael! ncdu: What's going on with this second size column? The only potential null is the return value of list(). 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. Some Interesting Facts: 1) void pointers cannot be dereferenced. When a variable is declared as being a pointer to type void, it is known as a generic pointer. LANG.MEM.NPDLANG.STRUCT.NTADLANG.STRUCT.UPD, Null pointer dereferenceNull test after dereferenceUnchecked parameter dereference, Can detect violations of this rule. Recovering from a blunder I made while emailing a professor. To learn more, see our tips on writing great answers. When B is null, The control reaches inside the main if block only when length of A is 1. But passing 0 to memcpy() is not one of them. Do not dereference null pointers Created by Jeffrey Gennari, last modified by Jill Britton on Jan 18, 2023 Dereferencing a null pointer is undefined behavior. This is a feature that we are currently heavily working on to be able to switch off such kind of false positives. static-code-analysis Is a PhD visitor considered as a visiting scholar? 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. On many platforms, dereferencing a null pointer results inabnormal program termination, but this is not required by the standard. 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. That makes sense. This topic was automatically closed 7 days after the last reply. 5.2 Part 2 Sometimes a helper function is de ned to perform the memory allocation. rev2023.3.3.43278. 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 Whats the grammar of "For those whose stories they are"? How can I check before my flight that the cloud separation requirements in VFR flight rules are met? I believe in this case, either expression would work. The final NCCE is actually more insidious than it seems at first. 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.) 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. Hi Andreas, Thanks for the feedback. Finally my method is returning a response with value of restTemplate. 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! What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? Made code more compliant with other rules. Original Java Specification Request (JSR) - Java Community Process Powered by Discourse, best viewed with JavaScript enabled. In C# and Java, all reference types can point to null. The issue is: memcpy() and friends do not explicitly state that a null pointer is a valid pointer value, even if the number of bytes to copy is 0. What is null pointer exception in android. Aaron:I suspect we are talking past each other. 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. At best, such an exception will cause abrupt program termination. This compliant solution ensures that both input_str andthe pointer returned by malloc() are not null: This noncompliant code example is from a version of drivers/net/tun.c and affects Linux kernel 2.6.30 [Goodin 2009]: The sk pointer is initialized to tun->sk before checking if tun is a null pointer. . Avoid Returning null from Methods. The issue arises when dereferenced pointers are used. Maybe one of these methods is already doing what your methods is doing, and could be considered as replacement. What is a NullPointerException, and how do I fix it? Can I tell police to wait and call a lawyer when served with a search warrant? Is the God of a monotheism necessarily omnipotent? SonarQube - Null Pointer Dereference Issue java simonsirak (Simon Sirak) June 14, 2018, 1:18pm 1 Hi! 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. Connect and share knowledge within a single location that is structured and easy to search. Unlike reference types, pointer types are not tracked by the default garbage . Share Improve this answer Follow answered Oct 5, 2017 at 16:27 Small typo nit: "such as if i t pointed to freed memory" meant to say "if it" instead (removing whitespace). Using platform-specific means (e.g. - the incident has nothing to do with me; can I use this this way? Doing so will cause a NullPointerException to be thrown. Isn't easier just to check valid range of length? I don't need to do this validation again. Your code needs to do something about the possible NullPointerException when some exception is caught, because in this scenario the responseDto will be null. I reordered that code example to do all the checks before allocations. 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 And the semantics, as I said, are different. Ah, gotcha. Is there a single-word adjective for "having exceptionally strong moral principles"? 2008-2023 SonarSource S.A., Switzerland. attacker to bypass security measures. This will normally lead to an unhandled error, resulting in a segmentation fault. IDE extension that lets you fix coding issues before they exist! What is a serialVersionUID and why should I use it? Iflengthhas the value1, the addition yields 0, and png_malloc() subsequently returns a null pointer, which is assigned to chunkdata. Im currently using SonarQube version 5.6.6. better way to handle this is to store the result of method invocation in a variable. isEmpty(Collection collection) What is null pointer exception in android Smartadm.ru 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. Java Specification Participation Agreement version in use: 2.0. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Null Pointer Im having trouble understanding your problem. Batch split images vertically in half, sequentially numbering the output files, Recovering from a blunder I made while emailing a professor. You're in a company-managed project. Doing so will cause a NullReferenceException to be thrown. Find centralized, trusted content and collaborate around the technologies you use most. Why does the second compliant example permit using possibly-null pointers? How can I check before my flight that the cloud separation requirements in VFR flight rules are met? When should pointers be checked for NULL in C? java What should you do if somebody passes a null pointer for a parameter Then we hit memcpy with length 0. Write a semantic patch to nd cases where the result of calling kmalloc is dereferenced with no previous NULL pointer test. uninitialized reference-type class members. Issues Components. To learn more, see our tips on writing great answers. ncdu: What's going on with this second size column? At Did any DOS compatibility layers exist for any UNIX-like systems before DOS started to become outmoded? And the compliant solution guarantees that the pointer will be valid if the code calls memcpy(). https://stackoverflow.com/questions/47534436/, https://stackoverflow.com/questions/47534436/, java - Jenkins groovy : Error: java. IDE extension that lets you fix coding issues before they exist! Can I tell police to wait and call a lawyer when served with a search warrant? which would allow us to systematically observe what you are having. There is no guarantee that subsequent invocations are returning the same value, thats why issue is raised. Setup is effortless and analysis is automatic for most languages, Fast, accurate analysis; enterprise scalability. Making statements based on opinion; back them up with references or personal experience. A pointer to null (the 0 memory address) should never be dereferenced/accessed. To create a custom null validation method declare an attribute with name ValidatedNotNullAttribute and mark the parameter that is Sonar detects that res.getBody() can be null when you do the check res.getBody()==null. Why is there a voltage on my HDMI and coaxial cables? 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 . Report False-positive / False-negative [LTS] The new SonarQube LTS is here: SONARQUBE 9.9 LTS, SonarQube - Null Pointer Dereference Issue. C static code analysis: Null pointers should not be dereferenced Instead use String.valueOf (object). 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. Because null pointer dereferencing is undefined behavior, the compiler (GCC in this case) can optimize away the if (!tun) check because it is performed after tun->sk is accessed, implying that tun is non-null. Making statements based on opinion; back them up with references or personal experience. To learn more, see our tips on writing great answers. What is generic pointer? (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). Is null check needed before calling instanceof? How to avoid dereferencing null pointers in Java - Quora [PATCH v2] vsprintf: Do not have bprintf dereference pointers Thanks for contributing an answer to Stack Overflow! My code is GPL licensed, can I issue a license to have my code be distributed in a specific MIT licensed project? (/). SonarJava Version 5.9.2 (build 16552). Using Kolmogorov complexity to measure difficulty of problems? But no where in that particular idiom would a NULL pointer necessarily be deferenced. Does a summoned creature play immediately after being summoned by a ready action? This compliant solution eliminates the null pointer deference by initializing sk to tun->sk following the null pointer check. [JAVA] 3.9 - FP for S2259 Null pointers should not be dereferenced 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. The fact that you can't pass a null (no object) with a reference parameter can be a reason to use a pointer instead. "After the incident", I started to be more careful not to trip over things. [RSPEC-2259] - Jira As for today, the SE engine is able to explore non-overridable methods (static, for instance), when declared in the same file being analyzed. C# static code analysis: HTTP responses should not be vulnerable to Is it possible to create a concave light? context.RaiseException . Clearly the standard enumerates 1 case of undefined behavior, but makes no special mention of n=0. A null pointer stores a defined value, but one that is defined by the environment to not be a valid address for any member or object. 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 is generally accepted that zeroing a pointer is a good way to mark it as invalid and dereferencing an invalid pointer is a bug. Find null smart pointer dereferences with the Clang Static Analyzer Dereferencing a null pointer can lead to a denial of service. 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. Null pointers should not be dereferenced (#42) Issues - GitLab Reports. I've changed it to say null pointer instead of invalid pointer. Why void pointer cannot be dereferenced? Explained by Sharing Culture . Interactions/interfaces with C can't use references. COMP-PROG-MODULE-5-6-REVIEWER.pdf - Pointers to string How to fix int cannot be dereferenced? Explained by Sharing Culture I'd guess null pointers are not valid, even though they point to 0 bytes.