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This page is automatically generated from the "Automated Detection" sections in the individual guidelines. Do not modify this page directly. |
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Checker | Guideline | ||
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| DCL31-C. Declare identifiers before using them | |||
| DCL37-C. Do not declare or define a reserved identifier | |||
| EXP32-C. Do not access a volatile object through a nonvolatile reference | |||
| EXP44-C. Do not rely on side effects in operands to sizeof, _Alignof, or _Generic | |||
| INT36-C. Converting a pointer to integer or integer to pointer | |||
| FLP30-C. Do not use floating-point variables as loop counters | |||
| ARR37-C. Do not add or subtract an integer to a pointer to a non-array object MEM30 | |||
| ARR38-C. Guarantee that library functions do not form invalid pointers | |||
| MEM30-C. Do Do not access freed memory | |||
| MEM31-C. Free dynamically allocated memory when no longer needed | |||
| FIO30-C. Exclude user input from format strings | |||
| FIO34-C. Distinguish between characters read from a file and EOF or WEOF | |||
| FIO42-C. Close files when they are no longer needed | |||
| FIO46-C. Do not access a closed file | |||
| ENV31-C. Do not rely on an environment pointer following an operation that may invalidate it | |||
| ENV33-C. Do not call system() | |||
| ENV34-C. Do not store pointers returned by certain functions | |||
| MSC30-C. Do not use the rand() function for generating pseudorandom numbers | |||
| POS30-C. Use the readlink() function properly POS33-C. Do not use vfork() | |||
| POS34-C. Do not call putenv() with a pointer to an automatic variable as the argument | |||
| ARR02-C. Explicitly specify array bounds, even if implicitly defined by an initializer | |||
| DCL00-C. Const-qualify immutable objects | |||
| DCL01-C. Do not reuse variable names in subscopes | |||
| DCL02-C. Use visually distinct identifiers | |||
| DCL05-C. Use typedefs of non-pointer types only | |||
| ENV02-C. Beware of multiple environment variables with the same effective name | |||
| EXP05-C. Do not cast away a const qualification | |||
| EXP12-C. Do not ignore values returned by functions | |||
| EXP14-C. Beware of integer promotion when performing bitwise operations on integer types smaller than int | |||
| FIO08-C. Take care when calling remove() on an open file | |||
| FIO11-C. Take care when specifying the mode parameter of fopen() | |||
| FIO22-C. Close files before spawning processes | |||
| INT09-C. Ensure enumeration constants map to unique values | |||
| INT12-C. Do not make assumptions about the type of a plain int bit-field when used in an expression | |||
| MEM01-C. Store a new value in pointers immediately after free() | |||
| MEM07-C. Ensure that the arguments to calloc(), when multiplied, do not wrap | |||
| MSC17-C. Finish every set of statements associated with a case label with a break statement | |||
| MSC21-C. Use robust loop termination conditions | |||
| STR04-C. Use plain char for characters in the basic character set | |||
| STR05-C. Use pointers to const when referring to string literals | |||
| STR06-C. Do not assume that strtok() leaves the parse string unchanged | |||
| STR11-C. Do not specify the bound of a character array initialized with a string literal | |||
| Automatically detects simple violations of this rule, although it may return some false positives. It may not catch more complex violations, such as initialization within functions taking uninitialized variables as arguments. It does catch the second noncompliant code example, and can be extended to catch the first as well | EXP33-C. Do not read uninitialized memory | ||
| A module written in Compass/ROSE can detect violations of this rule | CON33-C. Avoid race conditions when using library functions | ||
| Can catch violations of this rule by scanning the printf() and scanf() family of functions. For each such function, any variable that corresponds to a %d qualifier (or any qualifier besides %j) and that is not one of the built-in types (char, short, int, long, long long) indicates a violation of this rule. To catch violations, ROSE would also have to recognize derived types in expressions, such as size_t | INT15-C. Use intmax_t or uintmax_t for formatted IO on programmer-defined integer types | ||
| Can detect all of these | MEM33-C. Allocate and copy structures containing a flexible array member dynamically | ||
| Can detect common violations of this rule. However, it cannot handle cases in which the value returned by fgetpos() is copied between several variables before being passed to fsetpos() | FIO44-C. Only use values for fsetpos() that are returned from fgetpos() | ||
| Can detect simple violations of this recommendation. In particular, it warns when two calls to ungetc() on the same stream are not interspersed with a file-positioning or file-read function. It cannot handle cases where ungetc() is called from inside a loop | FIO13-C. Never push back anything other than one read character | ||
| Can detect simple violations of this rule | STR30-C. Do not attempt to modify string literals | ||
| Can detect simple violations of this rule | FIO38-C. Do not copy a FILE object | ||
| Can detect simple violations of this rule | FIO39-C. Do not alternately input and output from a stream without an intervening flush or positioning call | ||
| Can detect simple violations of this rule. It needs to examine each expression and make sure that no variable is modified twice in the expression. It also must check that no variable is modified once, then read elsewhere, with the single exception that a variable may appear on both the left and right of an assignment operator | EXP30-C. Do not depend on the order of evaluation for side effects | ||
| Can detect some violations of this recommendation when checking EXP36-C. Do not cast pointers into more strictly aligned pointer types | MEM02-C. Immediately cast the result of a memory allocation function call into a pointer to the allocated type | ||
| Can detect some violations of this recommendation. In particular, it flags switch statements that do not have a default clause. ROSE should detect "fake switches" as well (that is, a chain of if statements each checking the value of the same variable). These if statements should always end in an else clause, or they should mathematically cover every possibility. For instance, consider the following: if (x > 0) { /* ... */ } else if (x < 0) { /* ... */ } else if (x == 0) { /* ... */ } | MSC01-C. Strive for logical completeness | ||
| Can detect some violations of this recommendation. In particular, it warns when chown(), stat(), or chmod() are called on an open file | FIO01-C. Be careful using functions that use file names for identification | ||
| Can detect some violations of this rule | STR32-C. Do not pass a non-null-terminated character sequence to a library function that expects a string | ||
| Can detect some violations of this rule | MEM34-C. Only free memory allocated dynamically | ||
| Can detect some violations of this rule (In particular, it ensures that all operations involving division or modulo are preceded by a check ensuring that the second operand is nonzero.) | INT33-C. Ensure that division and remainder operations do not result in divide-by-zero errors | ||
| Can detect some violations of this rule but cannot flag violations involving universal names | DCL23-C. Guarantee that mutually visible identifiers are unique | ||
| Can detect some violations of this rule. However, it can only detect violations involving abort() because assert() is implemented as a macro | ERR06-C. Understand the termination behavior of assert() and abort() | ||
| Can detect some violations of this rule. However, it does not flag implicit casts, only explicit ones | FLP34-C. Ensure that floating-point conversions are within range of the new type | ||
| Can detect some violations of this rule. In particular, it ensures that all calls to open() supply exactly two arguments if the second argument does not involve O_CREAT, and exactly three arguments if the second argument does involve O_CREAT | EXP37-C. Call functions with the correct number and type of arguments | ||
| Can detect some violations of this rule. In particular, it ensures that calls to open() that are preceded by a call to lstat() are also followed by a call to fstat(). | POS35-C. Avoid race conditions while checking for the existence of a symbolic link | ||
| Can detect some violations of this rule. In particular, it warns if the last element of a struct is an array with a small index (0 or 1) | DCL38-C. Use the correct syntax when declaring a flexible array member | ||
| Can detect some violations of this rule. In particular, it warns when calls to setgid() are immediately preceded by a call to setuid() | POS36-C. Observe correct revocation order while relinquishing privileges | ||
| Can detect some violations of this rule. In particular, it warns when the argument to malloc() is a variable that has not been compared against 0 or that is known at compile time to be 0 | MEM04-C. Beware of zero-length allocations | ||
| Can detect violations of the recommendation but cannot distinguish between incomplete array declarations and pointer declarations | ARR01-C. Do not apply the sizeof operator to a pointer when taking the size of an array | ||
| Can detect violations of the rule by using the same method as STR31-C. Guarantee that storage for strings has sufficient space for character data and the null terminator | ENV01-C. Do not make assumptions about the size of an environment variable | ||
| Can detect violations of the rule for single-file programs | SIG30-C. Call only asynchronous-safe functions within signal handlers | ||
| Can detect violations of this recommendationthe rule. However, it is unable to handle cases involving strcpy_s() or manual string copies such as the one in the first example | STR31-C. Guarantee that storage for strings has sufficient space for character data and the null terminator | ||
| Can detect violations of this recommendation | MSC05-C. Do not manipulate time_t typed values directly | ||
| MSC05-C. Do not manipulate time_t typed values directly | Can detect violations of this recommendation by flagging invocations of the following functions:atoi()scanf(), fscanf(), sscanf()Others? | ERR34-C. Detect errors when converting a string to a number | |
| Can detect violations of this recommendation when checking for violations of EXP12-C. Do not ignore values returned by functions and EXP34-C. Do not dereference null pointers | ERR33-C. Detect and handle standard library errors | ||
| Can detect violations of this recommendation when checking for violations of EXP12-C. Do not ignore values returned by functions and EXP34-C. Do not dereference null pointers | POS54-C. Detect and handle POSIX library errors | ||
| Can detect violations of this recommendation while checking for violations of recommendation DCL00-C. Const-qualify immutable objects | DCL13-C. Declare function parameters that are pointers to values not changed by the function as const | ||
| Can detect violations of this recommendation. However, it can detect only those violations where both bitwise and arithmetic operators are used in the same expression | INT14-C. Avoid performing bitwise and arithmetic operations on the same data | ||
| Can detect violations of this recommendation. In particular, it catches comparisons and operations where one operand is of type size_t or rsize_t and the other is not | INT01-C. Use rsize_t or size_t for all integer values representing the size of an object | ||
| Can detect violations of this recommendation. In particular, it checks to see if the arguments to an equality operator are of a floating-point type | FLP02-C. Avoid using floating-point numbers when precise computation is needed | ||
| Can detect violations of this recommendation. In particular, it flags any instance of a variable of type char (without a signed or unsigned qualifier) that appears in an arithmetic expression | INT07-C. Use only explicitly signed or unsigned char type for numeric values | ||
| Can detect violations of this recommendation. In particular, it looks for the size argument of malloc(), calloc(), or realloc() and flags when it does not find a sizeof operator in the argument expression. It does not flag if the return value is assigned to a char *; in this case a string is being allocated, and sizeof is unnecessary because sizeof(char) == 1 | EXP09-C. Use sizeof to determine the size of a type or variable | ||
| Can detect violations of this recommendation. In particular, it notes uses of the scanf() family of functions where on the type specifier is a floating-point or integer type | INT05-C. Do not use input functions to convert character data if they cannot handle all possible inputs | ||
| Can detect violations of this recommendation. Specifically, it reports violations ifA pointer to one object is type cast to the pointer of a different objectThe pointed-to object of the (type cast) pointer is then modified arithmetically | EXP11-C. Do not make assumptions regarding the layout of structures with bit-fields | ||
| Can detect violations of this recommendation. Specifically, Rose reports use of tmpnam(), tmpnam_s() Rose reports use of tmpnam(), tmpnam_s(), tmpfile(), and mktemp() | FIO21-C. Do not create temporary files in shared directories | ||
| Can detect violations of this recommendation. Specifically, it reports violations ifA pointer to one object is type cast to the pointer of a different objectThe pointed-to object of the (type cast) pointer is then modified arithmetically | EXP11-C. Do not make assumptions regarding the layout of structures with bit-fields | Can detect violations of this rule by ensuring that operations are checked for overflow before being performed (Be mindful of exception INT30-EX2 because it excuses many operations from rule by ensuring that operations are checked for overflow before being performed (Be mindful of exception INT30-EX2 because it excuses many operations from requiring validation, including all the operations that would validate a potentially dangerous operation. For instance, adding two unsigned ints together requires validation involving subtracting one of the numbers from UINT_MAX, which itself requires no validation because it cannot wrap.) | INT30-C. Ensure that unsigned integer operations do not wrap |
| Can detect violations of this rule for single-file programs | SIG31-C. Do not access shared objects in signal handlers | ||
| Can detect violations of this rule when checking for violations of INT07-C. Use only explicitly signed or unsigned char type for numeric values | STR34-C. Cast characters to unsigned char before converting to larger integer sizes | ||
| Can detect violations of this rule. Any assignment operation where the type of the assigned-to value is float or double, but all the expressions to the right of the assignment are integral, is a violation of this rule | FLP06-C. Convert integers to floating point for floating-point operations | ||
| Can detect violations of this rule. However, false positives may occur on systems with persistent handlers | SIG34-C. Do not call signal() from within interruptible signal handlers | ||
| Can detect violations of this rule. However, false warnings may be raised if limits.h is included | INT31-C. Ensure that integer conversions do not result in lost or misinterpreted data | Can detect violations of this rule. However, it does not flag explicit casts to void * and then back to another pointer type | EXP36-C. Do not cast pointers into more strictly aligned pointer typesnot result in lost or misinterpreted data |
| Can detect violations of this rule. 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). ROSE does not handle cases where an allocation is assigned to an lvalue that is not a variable (such as a struct member or C++ function call returning a reference)However, it does not flag explicit casts to void * and then back to another pointer type | EXP36EXP34-C. Do not dereference null pointerscast pointers into more strictly aligned pointer types | ||
| Can detect violations of this rule. In particular, it ensures that all functions registered with atexit() do not call functions such as exit() | ENV32-C. All exit handlers must return normally | ||
| Can detect violations of this rule. In particular, it ensures that the result of getenv() is stored in a const variable | ENV30-C. Do not modify the object referenced by the return value of certain functionsof certain functions | ||
| Can detect violations of this rule. In particular, it flags bitwise operations that involved variables not declared with unsigned type | INT13-C. Use bitwise operators only on unsigned operands | ||
| Can detect violations of this rule. In particular, it flags bitwise operations that involved variables not declared with unsigned type, ROSE ensures that any pointer returned by malloc(), calloc(), or realloc() is first checked for NULL before being used (otherwise, it is free()-ed). ROSE does not handle cases where an allocation is assigned to an lvalue that is not a variable (such as a struct member or C++ function call returning a reference) | EXP34-C. Do not dereference null pointers INT13-C. Use bitwise operators only on unsigned operands | ||
| Can detect violations of this rule. It automatically detects returning pointers to local variables. Detecting more general cases, such as examples where static pointers are set to local variables which then go out of scope, would be difficult | DCL30-C. Declare objects with appropriate storage durations | ||
| Can detect violations of this rule. It should look for patterns of (a op1 b) op2 c wherec has a bigger type than a or bNeither a nor b is typecast to c's typeop2 is assignment or comparison | INT18-C. Evaluate integer expressions in a larger size before comparing or assigning to that size | ||
| Can detect violations of this rule. Unsigned operands are detected when checking for INT13-C. Use bitwise operators only on unsigned operands | INT34-C. Do not shift an expression by a negative number of bits or by greater than or equal to the number of bits that exist in the operand | ||
| Could be configured to catch violations of this rule. The way to catch the noncompliant code example is to first hunt for example code that follows this pattern: for (LPWSTR pwszTemp = pwszPath + 2; *pwszTemp != L'\\'; *pwszTemp++;) In particular, the iteration variable is a pointer, it gets incremented, and the loop condition does not set an upper bound on the pointer. Once this case is handled, ROSE can handle cases like the real noncompliant code example, which is effectively the same semantics, just different syntax | ARR30-C. Do not form or use out-of-bounds pointers or array subscripts | ||
| Could catch violations of this rule by enforcing that any call to open() or fopen() is preceded by a canonicalization routine—that is, a call to realpath() or canonicalize_file_name(). This call will catch some false positives, as ROSE cannot tell when canonicalization is warranted. False positives can be reduced (but not eliminated) by only reporting instances of fopen() or open() where the file name string has some other processing done to it. This reflects the fact that canonicalization is only necessary for doing verification based on the file name string | FIO02-C. Canonicalize path names originating from tainted sources | ||
| Could check violations of this rule by examining the size expression to malloc() or memcpy() functions. Specifically, the size argument should be bounded by 0, SIZE_MAX, and, unless it is a variable of type size_t or rsize_t, it should be bounds-checked before the malloc() call. If the argument is of the expression a*b, then an appropriate check is if (a < < SIZE_MAX / b && amp; a > > 0) ... | MEM35-C. Allocate sufficient memory for an object | ||
| Could detect possible violations by flagging any signal handler that calls signal() to (re)assert itself as the handler for its signal | SIG01-C. Understand implementation-specific details regarding signal handler persistence | ||
| Could detect possible violations by reporting any function that has malloc() or free() but not both. This would catch some false positives, as there would be no way to tell if malloc() and free() are at the same level of abstraction if they are in different functions | MEM00-C. Allocate and free memory in the same module, at the same level of abstraction | ||
| Could detect possible violations of this recommendation by reporting expressions with side effects, including function calls, that appear on the right-hand side of an && or || operator | EXP02-C. Be aware of the short-circuit behavior of the logical AND and OR operators | ||
| Could detect possible violations of this rule by first flagging any usage of realloc(). Also, it could flag any usage of free that is not preceded by code to clear out the preceding memory, using memset. This heuristic is imperfect because it flags all possible data leaks, not just leaks of "sensitive" data, because ROSE cannot tell which data is sensitive | MEM03-C. Clear sensitive information stored in reusable resources | ||
| Could detect some violations of this rule (In particular, it could detect the noncompliant code example by searching for fgets(), followed by strlen() - 1, which could be −1. The crux of this rule is that a string returned by fgets() could still be empty, because the first char is '\0'. There are probably other code examples that violate this guideline; they would need to be enumerated before ROSE could detect them.) | FIO37-C. Do not assume that fgets() or fgetws() returns a nonempty string when successful | ||
| Could detect some violations of this rule. This rule applies only to untrusted file name strings, and ROSE cannot tell which strings are trusted and which are not. The best heuristic is to note if there is any verification of the file name before or after the fopen() call. If there is any verification, then the file opening should be preceded by an lstat() call and succeeded by an fstat() call. Although that does not enforce the rule completely, it does indicate that the coder is aware of the lstat-fopen-fstat idiom | FIO32-C. Do not perform operations on devices that are only appropriate for files | ||
| Could detect the specific noncompliant code example. It could identify when the result of a % operation might be negative and flag usage of that result in an array index. It could conceivably flag usage of any such result without first checking that the result is positive, but it would likely introduce many false positives | INT10-C. Do not assume a positive remainder when using the % operator | ||
| Could detect violations in the following manner: all calls to strncpy() and the other functions should be followed by an assignment of a terminating character to null-terminate the string | STR03-C. Do not inadvertently truncate a string | ||
| Could detect violations of this recommendation by flagging any comparison expression involving addition that could potentially overflow. For example, instead of comparing a + b < c (where b and c are compile-time constants) and b > c, the code should compare a < c - b. (This assumes a, b, c are unsigned ints. Usually b is small and c is an upper bound such as INT_MAX.) | INT08-C. Verify that all integer values are in range | ||
| Could detect violations of this recommendation by identifying any assignment expression as the top-level expression in an if or while statement | EXP45-C. Do not perform assignments in selection statements | ||
| Could detect violations of this recommendation by searching for the following pattern:Any expression that calls two functions between the same sequence pointsThose two functions both modify the value of a static variableThat static variable's value is referenced by code following the expression | EXP10-C. Do not depend on the order of evaluation of subexpressions or the order in which side effects take place | ||
| Could detect violations of this recommendation merely by searching for the use of "magic numbers" and magic strings in the code itself. That is, any number (except a few canonical numbers: −1, 0, 1, 2) that appears in the code anywhere besides where assigned to a variable is a magic number and should instead be assigned to a const integer, enum, or macro. Likewise, any string literal (except "" and individual characters) that appears in the code anywhere besides where assigned to a char* or char[] is a magic string | DCL06-C. Use meaningful symbolic constants to represent literal values | ||
| Could detect violations of this rule by ensuring that each library function is accompanied by the proper treatment of errno | ERR30-C. Set errno to zero before calling a library function known to set errno, and check errno only after the function returns a value indicating failureTake care when reading errno | ||
| Could detect violations of this rule by ensuring that floating-point operations are surrounded by feclearexcept() and fetestexcept(). It would need to look for type conversions to float or double, divisions (by a number not known to be nonzero), and multiplication. It may be wisest to apply this to all floating-point operations in general | FLP03-C. Detect and handle floating-point errors | ||
| Could detect violations of this rule by looking for signal handlers that themselves call signal(). A violation is reported if the call fails and the handler therefore checks errno. A violation also exists if the signal handler modifies errno without first copying its value elsewhere | ERR32-C. Do not rely on indeterminate values of errno | ||
| Could detect violations of this rule by seeing if the argument to a character handling function (listed above) is not an unsigned char | STR37-C. Arguments to character-handling functions must be representable as an unsigned char | ||
| Could detect violations of this rule merely by looking for calls to assert(), and if it can evaluate the assertion (due to all values being known at compile time), then the code should use static-assert instead; this assumes ROSE can recognize macro invocation | DCL03-C. Use a static assertion to test the value of a constant expression | ||
| Could detect violations of this rule merely by reporting functions that call abort(), exit(), or _Exit() inside an if or switch statement.This would also catch many false positives, as ROSE could not distinguish a library function from an application function | ERR05-C. Application-independent code should provide error detection without dictating error handling | ||
| Could flag possible violations of this rule by noting any pointer to struct that is passed to fread(), as the noncompliant code example demonstrates | FIO09-C. Be careful with binary data when transferring data across systems | ||
| Could report possible violations of this rule by flagging calls to open() that do not have an O_NOFOLLOW flag and that are not preceded by a call to lstat() and succeeded by a call to fstat | POS01-C. Check for the existence of links when dealing with files | ||
| Could report possible violations of this rule merely by reporting any open() or fopen() call that did not have a subsequent call to fstat() | FIO05-C. Identify files using multiple file attributes | ||
| Does not currently detect violations of this recommendation. Although the recommendation in general cannot be automated, because of the difficulty in enforcing contracts between a variadic function and its invokers, it would be fairly easy to enforce type correctness on arguments to the printf() family of functions | DCL11-C. Understand the type issues associated with variadic functions |