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.
Null pointers should not be dereferenced #1155 - GitHub 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. sonarqube Ticket opened : Thanks a lot for the minimalized reproducer ! Status: Dormant. Issues Components. The alert is related to the sonar rule : Null pointers should not be dereferenced. Im very new to sonar, is there a way to add methods to the whitelist? But the problem also exists in the compliant version, so I'm not so sure that it's really compliant. The libpng library allows applications to read, create, and manipulate PNG (Portable Network Graphics) raster image files. Unlike reference types, pointer types are not tracked by the default garbage . You're in a company-managed project. 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. static-code-analysis Why is there a voltage on my HDMI and coaxial cables? 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). I would therefore assert that a platform whose memcpy() did anything besides a no-op when given n=0 and valid source/destination pointers was not C-standards-compliant. This latter use of pointers is a combined boolean/satellite: the pointer being non-null indicates "I have this sister object", and it provides that object. The standard will simply copy 0 byteswhich is essentially a no-op. There are other problems with this code, as is noted in the rule. 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. - the incident has nothing to do with me; can I use this this way?
Analysis of Haiku Operating System (BeOS Family) by PVS-Studio. Part 1 SonarQube null pointers should not be dereferenced on try/catch, Sonarcube :Null pointers should not be dereferenced, How do you get out of a corner when plotting yourself into a corner. Thus we should check > this kstrdup() operation. These can be: Invoking a method from a null object. That makes sense. In order to fix this, just do the following: BodyType body=res.getBody (); if (body == null || body.getServiceResult () == null) { return; } You can then even reuse body after that. I suggest that this topic needs to include calloc() and realloc() Refer to Linux man pages online for more enlightenment about malloc(), and friends. Goal And if there is no pointer_default declaration, then the default default is ref.
With their flexibility, void pointers also bring some constraints. When and how should I use a ThreadLocal variable? Thanks for contributing an answer to Stack Overflow! Ah, gotcha. This topic was automatically closed 7 days after the last reply. 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.
FindBugs CORRECTNESS - I added an assertion to that compliant code example. Why do academics stay as adjuncts for years rather than move around? Using Kolmogorov complexity to measure difficulty of problems? 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. A common memory-leak idiom, is reallocating storage and assigning its address to a pointer that already points to allocated storage. Pointer members in structs are not checked. 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>. So no checking of the length is necessary (besides preventing integer overflow, which the compliant solution does). 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, This error was found in the following code: else if (foo.list().length > 0) { }, I attempted to resolve this by rewriting as: else if (null != foo.list() && foo.list().length > 0) { }, foo is an instance of the File class in Java, and is directly instantiated through new File(). public boolean isNameEmpty() { return getName().length() == 0; // Noncompliant; the result of getName() could be null, but isn't null-checked } . In this noncompliant code example, input_str is copied into dynamically allocated memory referenced by c_str. This is a matter of style, and also following code walkthrough. Whats the grammar of "For those whose stories they are"? While the engine is in practice already able to explore code from other files if needed (relying solely on bytecode), we restrain this approach to a limited set of well-known methods from standard libraries, for which we know that behaviors are correctly produced. How can we let this pass? Asking for help, clarification, or responding to other answers. assert(!invalid(p)); // or whatever, bool invalid(const void *p) { Additionally, if input_str is a null pointer, the call to strlen() dereferences a null pointer, also resulting in undefined behavior. 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). So Bar might not be initialized but then the last line of your example should not be evaluated in this case. On the command prompt, the same arguments work and the record is added in db but not when I call the stored procedure from inside java program CallableStatement insertStat = db_conn.prepareCall (" {call InsertCourses (?,?,?,?,?,?,?,? The approximation of the try catch flow is such that we consider an exception can be thrown just after the curly brace of the try. But when length of A is 1, the control never reaches the else block. Whoops, you're right. This sounds indeed like a bug in the flow when an exception is raised. Explain about call by reference with an .
Pointers in C Explained - They're Not as Difficult - freeCodeCamp.org strongSwan - strongSwan Vulnerability (CVE-2023-26463) IDE extension that lets you fix coding issues before they exist! Unfortunately, its actual state also has some limitations, like the one you are hitting here. 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. But when length of A is 1, the control never reaches the else block. Which @NotNull Java annotation should I use? Is it possible to create a concave light? And fwstr > is dereferenced in the following codes. Is there a proper earth ground point in this switch box? This compliant solution ensures that the pointer returned by png_malloc() is not null. When B is null, The control reaches inside the main if block only when length of A is 1. Then we hit memcpy with length 0. uninitialized reference-type class members.
How to avoid dereferencing null pointers in Java - Quora raiseException() return, Sonar Removing the check "exception != null" raises S2259 "Null pointers should not be dereferenced" on "throw exception".
Null Pointer Exception In Java - GeeksforGeeks - A computer science By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy.
CWE - CWE-476: NULL Pointer Dereference (4.10) - Mitre Corporation }. 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. In my experience, there are reasons to check for a NULL pointer other than dereferencing it. SonarQube - Null Pointer Dereference Issue java simonsirak (Simon Sirak) June 14, 2018, 1:18pm 1 Hi! Identify where the allocation occurs.
What should you do if somebody passes a null pointer for a parameter 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. Can you please start a new thread and be more explicit about the issue you are observing. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA.
Null pointer - Wikipedia This engine is validating execution paths and checking for non-null values or null-check along the way, exploring all the possibilities. util.regex.Matcher, java - Swing .getParent() . 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. I am a student implementing stack with singly linked list using C, following a book called Fundamentals of Data Structures in C.. I think "res.getBody() == null" checks null first so it should go to return line, not reach to next if condition. Why are physically impossible and logically impossible concepts considered separate in terms of probability? 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.
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. Is there a proper earth ground point in this switch box? Asking for help, clarification, or responding to other answers. It is useful to have a function with portable interface but platform-dependent implementation: extern bool invalid(const void *); Doing so will cause a NullReferenceException to be thrown.
Depending on whether the pointer is valid (i.e. In the complaint version, I like to make source code checking a little quicker by putting parenthesizes around arguments to |= or &= as. can have the value zero on a call to that function. 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.
Sonar: Null pointers should not be dereferenced - Stack Overflow Is it plausible for constructed languages to be used to affect thought and control or mold people towards desired outcomes? But passing 0 to memcpy() is not one of them. minimal code sample to reproduce (with analysis parameter, and potential instructions to compile). An awesome tip to avoid NPE is to return empty strings or empty collections rather than null. Software project. That is only true if possibleNumbers contains no element.. BTW: none of these warnings are shown by . isEmpty(Map map) The idea is not to guarantee validity, but to catch a substantial number of problems that could occur.
Null Dereference | OWASP Foundation Thank you for clarifying your assertion until I understood it properly. In some situations, however, dereferencing a null pointer can lead to the execution of arbitrary code [Jack 2007,van Sprundel 2006]. Just because something is a pointer does not mean you should call delete . A reference to null should never be dereferenced/accessed. 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. Trying to understand how to get this basic Fourier Series. At worst, it could expose debugging information that would be useful to an attacker, or 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. 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. Note that it doesn't know how to check for non-heap, non-stack. (C11, S7.24.2.1). 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 . There are many ways to resolve this. [4] which version of SonarQube are you using? Is there a single-word adjective for "having exceptionally strong moral principles"? In the meantime, Im locking this thread. All content is copyright protected. ), 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).
OpenSSL Releases Security Update - NHS Digital Find null smart pointer dereferences with the Clang Static Analyzer NULL vs Uninitialized pointer - An uninitialized pointer stores an undefined value.
Null pointers should not be dereferenced (#42) Issues - GitLab please explain null pointer dereference [Solved] (Java in General forum The issue of passing n=0 to memcpy() is distinct from null or invalid pointers. At 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.
Original Java Specification Request (JSR) - Java Community Process This issues is displayed by SonarQube. If you call connect() function, it better do the connection, but failing simply because some ptr is NULL is not good behaviour -- failures should . 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". How do you ensure that a red herring doesn't violate Chekhov's gun? If malloc() fails, it returns a null pointer that is assigned to c_str.
Null Pointer > Further, if kstrdup() returns NULL, we should return ERR_PTR(-ENOMEM) to > the caller site. The method isNR(minRating) is a helper method that validate among other things, if the object minRating is null. What are the effects of exceptions on performance in Java? Dereferencing > this null pointer may cause the kernel go wrong. Thanks for the feedback. Do "superinfinite" sets exist? 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. Im currently using SonarQube version 5.6.6. better way to handle this is to store the result of method invocation in a variable. That's true. So let me be more precise in my wording: I assert that a platform whose memcpy() did anything besides copy zero bytes when given n=0 and valid src and dest pointers was not C-standards-compliant. That noncompliant code example (it's currently the 3rd) came from the Linux kernel, whose source is publicly available. This cross-file approach analysis can be quite resource-consuming, and we are not ready to openly enable the feature. Dereferencing a null pointer can lead to a denial of service. Trying to understand how to get this basic Fourier Series. Not the answer you're looking for? What is generic pointer?
C static code analysis: Null pointers should not be dereferenced Not the answer you're looking for? On many platforms, dereferencing a null pointer results in abnormal program termination, but this is not required by the standard. 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. 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. You need to benchmark. What is a serialVersionUID and why should I use it? Interactions/interfaces with C can't use references.
Shouldn't the function check all pointers before dereferencing them or passing them to another function? Sonar is ok. Sonar can't determine that the helper method did the null validation. 3.7. NullPointerException is a RuntimeException. Should trycatch go inside or outside a loop? A bug can cause them never to be reassigned. All rights are expressly reserved. I feel my situation is not as complicated. Powered by Discourse, best viewed with JavaScript enabled.
PDF Fourth Coccinelle Workshop { Exercises Pointer Arithmetic in c - Unit - 4 1. Define pointer. Explain about the Find centralized, trusted content and collaborate around the technologies you use most. Mutually exclusive execution using std::atomic?
Why void pointer cannot be dereferenced? Explained by Sharing Culture But what exactly does it mean to "dereference a null pointer"? By explicitly teaching the C++ standard class behaviors we can make the Analyzer to find more bugs related to modern C++ code. What methods/tools can be used to determine the cause so that you stop the exception from causing the progra. 4500 Fifth Avenue
Some Interesting Facts: 1) void pointers cannot be dereferenced. Is the God of a monotheism necessarily omnipotent? Is null check needed before calling instanceof? positive S2637 in SonarQube 6.7.1 LTS, Sonar false positive, "change condition so that it does not always evaluate to true. It's even called out explicitly in C17 7.24.1p2: Where an argument declared as size_t n specifies the length of the array for a function, n can have the value zero on a call to that function. Is there a single-word adjective for "having exceptionally strong moral principles"? By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. validated for null in your method declaration with it: 2008-2023 SonarSource S.A., Switzerland. To learn more, see our tips on writing great answers. SONAR, SONARSOURCE, SONARLINT, SONARQUBE and SONARCLOUD are trademarks of SonarSource S.A. All other trademarks and copyrights are the property of their respective owners. IDE extension that lets you fix coding issues before they exist! I'd guess WG14 has considered these questions, but I haven't until now :). When length is zero, it is probably unusable condition for this function. This solution also ensures that theuser_data pointer is not null. To learn more, see our tips on writing great answers. Isn't easier just to check valid range of length? There are many ways to resolve this. ncdu: What's going on with this second size column? Put a new ResponseEntity is wrong because I won't know what will be the answer for the status of http. Recovering from a blunder I made while emailing a professor. attacker to bypass security measures. You can use Optional instead. Privacy Policy, Detect issues in your GitHub, Azure DevOps Services, Bitbucket Cloud, GitLab repositories.
C# static code analysis: Null pointers should not be dereferenced SonarLint: A "NullPointerException" could be thrown; "getBody()" can return null. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. We cannot understand how there could be a null pointer exception at the reported line. Off by one error: It is the third example. 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. Thered be huge value in jumping onto the latest version of the ecosystem (notably SonarQube), and benefit from all latest analyzers (e.g. Even if the object is null in this case, it will not give an exception and will print ' null ' to the output stream. Software Engineering Institute
Dereferencing a null pointer is undefined behavior, typically abnormal program termination. 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 can I check before my flight that the cloud separation requirements in VFR flight rules are met? Perhaps this could be done with a special constraint that will notify the SE engine that we learned from a Debug.Assert call. Appropriate typecasting is necessary. What sort of strategies would a medieval military use against a fantasy giant? SonarJava. 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. So we have to check all the arguments before performing any actions. io.NotSerializableException : java. However, memory allocation > functions such as kstrdup() may fail and returns NULL. 2008-2023 SonarSource S.A., Switzerland. Carnegie Mellon University
To learn more, see our tips on writing great answers. Basically, yes. Asking for help, clarification, or responding to other answers. 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?) Correct; a null pointer is not a valid pointer for the C library functions. Avoid Returning null from Methods. What does it mean that a reference must refer to an object, not a dereferenced null pointer? context.RaiseException .
Sonar violation: Null pointers should not be dereferenced #7459 - GitHub Why does Mister Mxyzptlk need to have a weakness in the comics? 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 also adds assertions to document that certain other pointers must not be null. A reference to null should never be dereferenced/accessed. Minimising the environmental effects of my dyson brain. Made code more compliant with other rules.
False fault 'Null pointers should not be dereferenced' using Optional How to convert the address of a dereferenced pointer from C to C# We.
C# static code analysis: HTTP responses should not be vulnerable to Your assertion is not backed by the wording in the standard, nor by common implementer understanding.
SonarQube - Null Pointer Dereference Issue - Sonar Community In the code, we check the not nullity with java.util.Objects.nonNull(). The SonarJava SE engine is however, by default, not configured to explore methods declared in other files (in your case, your utility class CheckUtils). 1 Answer Sorted by: 1 Your code is ok. 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. 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). So Bar might not be initialized but then the last line of your example should not be evaluated in this case. 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. 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. return p == NULL || (char *)p < &_etext; versions used (SonarQube, Scanner, language analyzer) Extended Description NULL pointer dereference issues can occur through a number of flaws, including race conditions, and simple programming omissions. Essentially, this code and the previous dereference disagree as to whether this value is allowed to be null. There is no legitimate reason to dereference a null pointer unless you on a rare system that maps page zero (or you intend your program to crash). There is no guarantee that subsequent invocations are returning the same value, thats why issue is raised. Finally, there is the matter of the compliant solution. java Aaron:I suspect we are talking past each other. Setup is effortless and analysis is automatic for most languages, Fast, accurate analysis; enterprise scalability. This rule applies to all null pointers, regardless of which function returned them. Now, you can find the list of whitelisted methods here. Maybe one of these methods is already doing what your methods is doing, and could be considered as replacement. (I think you cover that in a different rule.) (In contrast, the case of passing 0 bytes to malloc is addressed in C11.) The same problem we will have with "Add at least one assertion to this test case."
Connect and share knowledge within a single location that is structured and easy to search. Clearly the standard enumerates 1 case of undefined behavior, but makes no special mention of n=0. LANG.MEM.NPDLANG.STRUCT.NTADLANG.STRUCT.UPD, Null pointer dereferenceNull test after dereferenceUnchecked parameter dereference, Can detect violations of this rule. 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.
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