Why are Suriname, Belize, and Guinea-Bissau classified as "Small Island Developing States"? Software project. The final NCCE is actually more insidious than it seems at first. The null pointer check for writing or dereferencing should be a compiler flag or library setting. As for copy vs pointer/reference - it depends. This is a feature that we are currently heavily working on to be able to switch off such kind of false positives. Note that it doesn't know how to check for non-heap, non-stack. You do not have permission to delete messages in this group, Either email addresses are anonymous for this group or you need the view member email addresses permission to view the original message. https://stackoverflow.com/questions/47534436/, https://stackoverflow.com/questions/47534436/, java - Jenkins groovy : Error: java. It looks like a logic bug, which can cause a memory leaking. Provide a self-contained reproducer (zipped project?) SIZE_MAX is the largest possible value that a size_t could take, so it is not possible to have anything larger than SIZE_MAX. Essentially, this code and the previous dereference disagree as to whether this value is allowed to be null. NULL vs Void Pointer - Null pointer is a value, while void pointer is a type. Using Kolmogorov complexity to measure difficulty of problems? What is null pointer exception in android. Please direct comments on this JSR to the Spec Lead (s) Team. Issues Components. When I added the not null validation as sonar suggest. sonarLint (3.2.) A bug can cause them never to be reassigned. Carnegie Mellon University [4] We seem to have a false positive for "Null pointers should not be dereferenced" - squid:S2259. Passing ownership of something also requires pointers. Is it possible to create a concave light? Does it just mean failing to correctly check if a value is null? Null pointer should not be dereferenced , In layman's terms, a null pointer is a pointer to an address in the memory space that does not have a meaningful value and cannot be referenced by the calling program, for whatever reason. "After the incident", I started to be more careful not to trip over things. SonarLint: A "NullPointerException" could be thrown; "getBody()" can return null. Shouldn't the function check all pointers before dereferencing them or passing them to another function? By 'valid pointers' I mean that both src and dest pointers are not null and they both point to non-overlapping arrays containing at least n bytes each. Not the answer you're looking for? which version of SonarQube are you using? in above code, Reports. . We resolved it by adding our tools path in the white list, and repackaging it. As for today, the SE engine is able to explore non-overridable methods (static, for instance), when declared in the same file being analyzed. If not, this might be a bug. isEmpty(Map map) Making statements based on opinion; back them up with references or personal experience. In C/C++ speak, 'dereferencing' simply means getting the object that a pointer . On many platforms, dereferencing a null pointer results in abnormal program termination, but this is not required by the standard. Best to cite C11 s7.24.2.1 here: The memcpy function copies n characters from the object pointed to by s2 into the object pointed to by s1. Connect and share knowledge within a single location that is structured and easy to search. 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. Doing so will cause a NullReferenceException to be thrown. Much like dereferencing a dangling (or wild) pointer leads to undefined behavior, dereferencing a null pointer also leads to undefined behavior. Find centralized, trusted content and collaborate around the technologies you use most. What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? This issues is displayed by SonarQube. Sonar is ok. Made code more compliant with other rules. So no checking of the length is necessary (besides preventing integer overflow, which the compliant solution does). All content is copyright protected. Off by one error: It is the third example. 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). SonarJava. 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. Seems the analizer don't recognice the logic with the funcional object Optional. ii. 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. http://blog.llvm.org/2011/05/what-every-c-programmer-should-know_14.html. The SonarJava SE engine is however, by default, not configured to explore methods declared in other files (in your case, your utility class CheckUtils). 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 */ By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. How can I check before my flight that the cloud separation requirements in VFR flight rules are met? Void pointers cannot be dereferenced as any other pointer. {"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. If malloc() fails, it returns a null pointer that is assigned to c_str. 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. Software project. 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. Can you please start a new thread and be more explicit about the issue you are observing. I have checked on multiple . Agreed. isEmpty(Collection collection) The issue of passing n=0 to memcpy() is distinct from null or invalid pointers. SONAR, SONARSOURCE, SONARLINT, SONARQUBE and SONARCLOUD are trademarks of SonarSource S.A. All other trademarks and copyrights are the property of their respective owners. LANG.MEM.NPDLANG.STRUCT.NTADLANG.STRUCT.UPD, Null pointer dereferenceNull test after dereferenceUnchecked parameter dereference, Can detect violations of this rule. 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. Linear regulator thermal information missing in datasheet, Identify those arcade games from a 1983 Brazilian music video. One could argue that all code examples would be redundant with the first pair. What can a lawyer do if the client wants him to be acquitted of everything despite serious evidence? Appropriate typecasting is necessary. Dereferencing a null pointer results in undefined behavior. But no where in that particular idiom would a NULL pointer necessarily be deferenced. It is still a pointer though, to use it you just have to cast it to another kind of pointer first. context.RaiseException . rev2023.3.3.43278. With their flexibility, void pointers also bring some constraints. Trying to understand how to get this basic Fourier Series. 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. Its purpose is to serve as a special value for a pointer that could indicate a special condition in your program. name result . I reordered that code example to do all the checks before allocations. attacker to bypass security measures. Ah, gotcha. It also uses the unsigned type size_t to pass the length parameter, ensuring that negative values are not passed to func(). Goal Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. When c_str is dereferenced in memcpy(), the program exhibits undefined behavior. 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. Unfortunately, its actual state also has some limitations, like the one you are hitting here. At worst, it could expose debugging information that would be useful to an attacker, or it could allow an attacker to bypass security measures. Is it suspicious or odd to stand by the gate of a GA airport watching the planes? Is there a single-word adjective for "having exceptionally strong moral principles"? Phew, we're agreed here. In C# and Java, all reference types can point to null. Isn't easier just to check valid range of length? Doing so will at best cause abrupt program termination, without the I doubt that "length" of zero is a valid parameter, and although there no copy, but we see memory allocation. 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. That is, sets equivalent to a proper subset via an all-structure-preserving bijection. Powered by Discourse, best viewed with JavaScript enabled. Not the answer you're looking for? Search for vulnerabilities resulting from the violation of this rule on the CERT website. 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. 0 is certainly within the 'domain of the function' (a phrase defined by mathematics but not by C11), as copying 0 bytes is well-understood (although silly). 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. How to deal with "java.lang.OutOfMemoryError: Java heap space" error? 1 Null pointers should not be dereferenced @CheckForNull String getName(){.} "After the incident", I started to be more careful not to trip over things. . Sonar detects that res.getBody() can be null when you do the check res.getBody()==null. We really appreciate your help. 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. If the project is not compiled, and without sonar.java.binaries whether the white list takes effect? 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 can we let this pass? I was fixing some issues gathered by SonarQube when I stumbled upon the following issue: "SonarQube violation: Possible null pointer dereference in ___ due to return value of called method" When and how should I use a ThreadLocal variable? Obviously the value of that pointer could have changed since the . What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? 2008-2023 SonarSource S.A., Switzerland. Sonar is ok. Sonar can't determine that the helper method did the null validation. 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. 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. In this noncompliant code example, input_str is copied into dynamically allocated memory referenced by c_str. Whoops, you're right. 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 It could be non-null the first time but not the second time, sonar does not know this. Im currently using SonarQube version 5.6.6. better way to handle this is to store the result of method invocation in a variable. See C17 7.1.4p1, which says, in part: Each of the following statements applies unless explicitly stated otherwise in the detailed descriptions that follow: 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 pointerto 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. ncdu: What's going on with this second size column? 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". Asking for help, clarification, or responding to other answers. io.NotSerializableException : java. Depending on whether the pointer is valid (i.e. util.regex.Matcher, java - Swing .getParent() . A reference to null should never be dereferenced/accessed. - the incident has nothing to do with me; can I use this this way?