Mercurial > dropbear
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 |
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#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; }