Connect and share knowledge within a single location that is structured and easy to search. Shouldn't the function check all pointers before dereferencing them or passing them to another function? In the code, we check the not nullity with java.util.Objects.nonNull(). 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. If not, this might be a bug. 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). points to memory allocated to the process) and what exactly was allocated there after the public key was freed, this may cause a segmentation fault or even execute code, which could again cause a segmentation fault, but might potentially be under the attacker's control. 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.) All content is copyright protected. ability to run any cleanup processes. Is it suspicious or odd to stand by the gate of a GA airport watching the planes? 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. If you write [ref], then a null pointer is not allowed, but if you write [unique], then a null pointer is permitted. I have checked on multiple . We can see that at obj.run(), obj can not be null, but is pointed out by Sonar. So we have to check all the arguments before performing any actions. Correct; a null pointer is not a valid pointer for the C library functions. Whoops, you're right. So no checking of the length is necessary (besides preventing integer overflow, which the compliant solution does). SonarQube - Null Pointer Dereference Issue - Sonar Community null(java.lang.NullPointerException) . Do not use a null in a case where an object is required, https://gcc.gnu.org/gcc-4.9/porting_to.html, Prior to 2018-01-12: CERT: Unspecified Relationship, Pointer Casting and Pointer Type Changes [HFC], Dereferencing an out-of-domain pointer [nullref], Section 5.2.18, "Null-Pointer Dereference", Dereferencing null pointers that were not returned by a function. 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 . https://stackoverflow.com/questions/47534436/, https://stackoverflow.com/questions/47534436/, java - Jenkins groovy : Error: java. I think "res.getBody() == null" checks null first so it should go to return line, not reach to next if condition. Find centralized, trusted content and collaborate around the technologies you use most. This compliant solution eliminates the null pointer deference by initializing sk to tun->sk following the null pointer check. Currently I'm working with SonarQube solving issues but I'm facing a trouble to how handle null pointers that shouldn't be dereferenced. There are many ways to resolve this. 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. The problem is that something like %*pbl which reads a bitmask, will save the pointer to the bitmask in the buffer. return p == NULL || (char *)p < &_etext; name result . NullPointerException is a RuntimeException. At worst, it could expose debugging information that would be useful to an attacker, or it could allow an attacker to bypass security measures. how to handle Sonarlint java:S2259 (Null pointers should not be The expected result here is solve the issue with sonarqube. assert(!invalid(p)); // or whatever, bool invalid(const void *p) { There is a missing check for the return value from . You can use Optional instead. At best, such an exception will cause abrupt program termination. . the Java one). Trying to understand how to get this basic Fourier Series. We resolved it by adding our tools path in the white list, and repackaging it. How do you ensure that a red herring doesn't violate Chekhov's gun? In the simplest case, this function just returns the result of calling kmalloc. Whats the grammar of "For those whose stories they are"? Styling contours by colour and by line thickness in QGIS. When B is null, The control reaches inside the main if block only when length of A is 1. Is it plausible for constructed languages to be used to affect thought and control or mold people towards desired outcomes? 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. This is a matter of style, and also following code walkthrough. There is no guarantee that subsequent invocations are returning the same value, thats why issue is raised. Pointer members in structs are not checked. Also, the term 'pointer' is bad (but maybe it comes from the FindBugs tool): Java doesn't have pointers, it has references. 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. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Im very new to sonar, is there a way to add methods to the whitelist? it could allow an attacker to bypass security measures. Null Pointer Doing so will cause a NullPointerException to be thrown. On many platforms, dereferencing a null pointer results inabnormal program termination, but this is not required by the standard. positive S2637 in SonarQube 6.7.1 LTS, Sonar false positive, "change condition so that it does not always evaluate to true. Find centralized, trusted content and collaborate around the technologies you use most. Much like dereferencing a dangling (or wild) pointer leads to undefined behavior, dereferencing a null pointer also leads to undefined behavior. Many platforms can support testing for those also. > Further, if kstrdup() returns NULL, we should return ERR_PTR(-ENOMEM) to > the caller site. How to convert the address of a dereferenced pointer from C to C# ncdu: What's going on with this second size column? sonar_etReines-CSDN 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. Dereferencing a null pointer results in undefined behavior. I believe in this case, either expression would work. 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. Trying to understand how to get this basic Fourier Series. What is the point of Thrower's Bandolier? When and how should I use a ThreadLocal variable? References, C++ FAQ 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. 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. uninitialized reference-type class members. isEmpty(Collection collection) please explain null pointer dereference [Solved] (Java in General forum One could argue that all code examples would be redundant with the first pair. Passing a null pointer tomemcpy() would produce undefined behavior, even if the number of bytes to copy were 0. 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 Asking for help, clarification, or responding to other answers. Removing the check "exception != null" raises S2259 "Null pointers should not be dereferenced" on "throw exception". https://www.yammer.com/ http://feeds.feedburner.com/office/fmNx Why does the second compliant example permit using possibly-null pointers? My below code where I'm calling a stored procedure is giving a null pointer exception. It is still a pointer though, to use it you just have to cast it to another kind of pointer first. 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. which would allow us to systematically observe what you are having. sonarLint (3.2.) The method isNR(minRating) is a helper method that validate among other things, if the object minRating is null. I've changed it to say null pointer instead of invalid pointer. By explicitly teaching the C++ standard class behaviors we can make the Analyzer to find more bugs related to modern C++ code. 1 Answer Sorted by: 1 Your code is ok. In C++, does dereferencing a nullptr itself cause undefined behaviour We seem to have a false positive for "Null pointers should not be dereferenced" - squid:S2259. . Reports. Dereferencing a null pointer can lead to a denial of service. We really appreciate your help. Just a few words about the rule now. Null pointer should not be dereferenced . Automated Detection Null pointer dereferences can happen in path-dependent ways. ncdu: What's going on with this second size column? It looks like a logic bug, which can cause a memory leaking. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. ssize_t (*aio_read)(struct kiocb *, char __user *, size_t . EXP34-C. Do not dereference null pointers - Confluence Callable statement giving Null Pointer Exception - Oracle Forums "After the incident", I started to be more careful not to trip over things. )}"); 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. I believe that dereferencing NULL should not crash the system, should not allow a write to a NULL pointer area, but should always set errno, If I am a hacker, could I trap a null failure that would force a memory dump. However there is no portable way to verify that the pointer is valid, other than checking for null. Your code needs to do something about the possible NullPointerException when some exception is caught, because in this scenario the responseDto will be null. 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. , . To learn more, see our tips on writing great answers. Instead use String.valueOf (object). Does it just mean failing to correctly check if a value is null? 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. Is there a single-word adjective for "having exceptionally strong moral principles"? Please direct comments on this JSR to the Spec Lead (s) Team. 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. For the time being, I would unfortunately recommend to mark as False Positive the issue. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. A common memory-leak idiom, is reallocating storage and assigning its address to a pointer that already points to allocated storage. The correct idiom is to only allocate storage if the pointer is currently NULL.

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