New: It should be documented that using fexecve on a file opened in O_CLOEXEC that is a script cannot possibly work.

https://bugzilla.kernel.org/show_bug.cgi?id=74481

Bug ID: 74481
Summary: It should be documented that using fexecve on a file
opened in O_CLOEXEC that is a script cannot possibly
work.
Product: Documentation
Version: unspecified
Hardware: All
OS: Linux
Status: NEW
Severity: normal
Priority: P1
Component: man-pages
Assignee: documentation_man-pages-ztI5WcYan/[email protected]
Reporter: [email protected]
Regression: No

Consider the following program:

#include <errno.h>
#include <fcntl.h>
#include <unistd.h>

int main()

{
    int test = open("./test.sh", O_RDONLY | O_CLOEXEC);
    if (-1 == test) {
        perror("open");
    }

    char * const argv[] = {
        (char *) "./test.sh",
        NULL
    };
    char * const env[] = { NULL };
    fexecve(test, argv, env);
    perror("fexecve");

    return 0;
}

and the following script:

#! /usr/bin/env dash

echo 'hello world!'

When the C program is run, it cannot work because by the time the interpreter has the passed in file name "/proc/self/fd/${FD}" it has already been closed. This is a strange corner case that should be documented.

https://bugzilla.kernel.org/show_bug.cgi?id=74481

Bug ID: 74481
Summary: It should be documented that using fexecve on a file
opened in O_CLOEXEC that is a script cannot possibly
work.
Product: Documentation
Version: unspecified
Hardware: All
OS: Linux
Status: NEW
Severity: normal
Priority: P1
Component: man-pages
Assignee: documentation_man-pages-ztI5WcYan/[email protected]
Reporter: [email protected]
Regression: No

Consider the following program:

#include <errno.h>
#include <fcntl.h>
#include <unistd.h>

int main()

{
    int test = open("./test.sh", O_RDONLY | O_CLOEXEC);
    if (-1 == test) {
        perror("open");
    }

    char * const argv[] = {
        (char *) "./test.sh",
        NULL
    };
    char * const env[] = { NULL };
    fexecve(test, argv, env);
    perror("fexecve");

    return 0;
}

and the following script:

#! /usr/bin/env dash

echo 'hello world!'

When the C program is run, it cannot work because by the time the interpreter has the passed in file name "/proc/self/fd/${FD}" it has already been closed. This is a strange corner case that should be documented.