Attachment 179980 Details for Bug 217062 – Minimal test

Minimal test

test_noexec.c (text/plain), 1.27 KB, created by shamaz.mazum on 2017-02-14 10:42:23 UTC

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Creator: shamaz.mazum

Created: 2017-02-14 10:42:23 UTC

Size: 1.27 KB

patch

obsolete

>#include <fcntl.h>
>#include <unistd.h>
>#include <sys/mman.h>
>#include <stdlib.h>
>#include <stdio.h>
>
>int main (int argc, char *argv[])
>{
>    if (argc != 2)
>    {
>        fprintf (stderr, "Usage: test <path-to-file-in-noexec-fs>\n");
>        return 1;
>    }
>
>    int fd = open (argv[1], O_RDONLY);
>    if (fd == -1)
>    {
>        perror ("Cannot open the file");
>        return 1;
>    }
>
>    /*
>     * Here is the interesting part. The file associated with fd lies on no-exec file system,
>     * Is it correct behaviour to allow PROT_EXEC protection here?
>     */
>
>    void *area = mmap (NULL, 4096, PROT_READ | PROT_EXEC, MAP_PRIVATE, fd, 0);
>    if (area == MAP_FAILED)
>    {
>        perror ("mmap test OK. Cannot map a file with PROT_EXEC");
>        goto done;
>    }
>
>    /*
>     * Here is the trick. You can set PROT_EXEC in mmap but cannot in mprotect.
>     */
>
>    printf ("mmap test failure. Mapped a no-exec file with PROT_EXEC\n");
>    int res;
>    mprotect (area, 4096, PROT_NONE);
>    res = mprotect (area, 4096, PROT_READ|PROT_EXEC);
>    if (res == -1)
>    {
>        perror ("mprotect test OK.");
>        goto done;
>    }
>    printf ("mprotect test failure. Mapped a no-exec file with PROT_EXEC\n");
>
>done:
>
>    if (area != MAP_FAILED) munmap (area, 4096);
>    close (fd);
>    return 0;
>}

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Attachments on bug 217062: 179941 | 179980 | 179995