proot: Properly handle relocated embedded loader

The _binary_loader_exe_size variable can be relocated by Android linker
which makes it unusable, rely instead on end-start which can be
relocated

Also don't reject binaries with linker having it's own DT_INTERP section
(like /system/bin/linker on ARM Android)
This commit is contained in:
michalbednarski 2016-03-20 12:18:58 +01:00
parent ab9c603c48
commit 788935ae8d

View File

@ -0,0 +1,42 @@
--- PRoot-5.1.0/src/execve/enter.c 2014-12-15 15:18:11.000000000 +0100
+++ src/src/execve/enter.c 2016-03-20 12:05:08.013426156 +0100
@@ -454,10 +454,10 @@
}
extern unsigned char _binary_loader_exe_start;
-extern unsigned char _binary_loader_exe_size;
+extern unsigned char _binary_loader_exe_end;
extern unsigned char WEAK _binary_loader_m32_exe_start;
-extern unsigned char WEAK _binary_loader_m32_exe_size;
+extern unsigned char WEAK _binary_loader_m32_exe_end;
/**
* Extract the built-in loader. This function returns NULL if an
@@ -483,11 +483,11 @@
if (wants_32bit_version) {
start = (void *) &_binary_loader_m32_exe_start;
- size = (size_t) &_binary_loader_m32_exe_size;
+ size = (size_t) (&_binary_loader_m32_exe_end - &_binary_loader_m32_exe_start);
}
else {
start = (void *) &_binary_loader_exe_start;
- size = (size_t) &_binary_loader_exe_size;
+ size = (size_t) (&_binary_loader_exe_end - &_binary_loader_exe_start);
}
status2 = write(fd, start, size);
@@ -645,8 +645,10 @@
/* An ELF interpreter is supposed to be
* standalone. */
- if (tracee->load_info->interp->interp != NULL)
- return -EINVAL;
+ if (tracee->load_info->interp->interp != NULL) {
+ TALLOC_FREE(tracee->load_info->interp->interp);
+ // TODO: Print warning?
+ }
}
compute_load_addresses(tracee);