view fuzz/fuzz-harness.c @ 1930:299f4f19ba19

Add /usr/sbin and /sbin to default root PATH When dropbear is used in a very restricted environment (such as in a initrd), the default user shell is often also very restricted and doesn't take care of setting the PATH so the user ends up with the PATH set by dropbear. Unfortunately, dropbear always sets "/usr/bin:/bin" as default PATH even for the root user which should have /usr/sbin and /sbin too. For a concrete instance of this problem, see the "Remote Unlocking" section in this tutorial: https://paxswill.com/blog/2013/11/04/encrypted-raspberry-pi/ It speaks of a bug in the initramfs script because it's written "blkid" instead of "/sbin/blkid"... this is just because the scripts from the initramfs do not expect to have a PATH without the sbin directories and because dropbear is not setting the PATH appropriately for the root user. I'm thus suggesting to use the attached patch to fix this misbehaviour (I did not test it, but it's easy enough). It might seem anecdotic but multiple Kali users have been bitten by this. From https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=903403
author Raphael Hertzog <hertzog@debian.org>
date Mon, 09 Jul 2018 16:27:53 +0200
parents be236878efcf
children
line wrap: on
line source

#include "includes.h"
#include "buffer.h"
#include "dbutil.h"

extern int LLVMFuzzerTestOneInput(const unsigned char *data, size_t size);

int main(int argc, char ** argv) {
    int i;
    buffer *input = buf_new(100000);
    int quiet = 0;

    for (i = 1; i < argc; i++) {
#if DEBUG_TRACE
        if (strcmp(argv[i], "-v") == 0) {
            debug_trace++;
            fprintf(stderr, "debug level -> %d\n", debug_trace);
        }
#endif
        if (strcmp(argv[i], "-q") == 0) {
            printf("Running quiet\n");
            quiet = 1;
        }
    }

    int old_fuzz_wrapfds = 0;
    for (i = 1; i < argc; i++) {
        if (argv[i][0] == '-') {
            /* ignore arguments */
            continue;
        }

        char* fn = argv[i];
        buf_setlen(input, 0);
        buf_readfile(input, fn);
        buf_setpos(input, 0);

		/* Run twice to catch problems with statefulness */
        fuzz.wrapfds = old_fuzz_wrapfds;
        if (!quiet) {
            printf("Running %s once \n", fn);
        }
        LLVMFuzzerTestOneInput(input->data, input->len);
        if (!quiet) {
            printf("Running %s twice \n", fn);
        }
        LLVMFuzzerTestOneInput(input->data, input->len);
        if (!quiet) {
            printf("Done %s\n", fn);
        }

        /* Disable wrapfd so it won't interfere with buf_readfile() above */
        old_fuzz_wrapfds = fuzz.wrapfds;
        fuzz.wrapfds = 0;
    }

    printf("Finished\n");

    return 0;
}

// Just to let it link
size_t LLVMFuzzerMutate(uint8_t *UNUSED(Data), size_t UNUSED(Size), size_t UNUSED(MaxSize)) {
    printf("standalone fuzzer harness shouldn't call LLVMFuzzerMutate");
    abort();
    return 0;
}