diff options
| author | Mike Frysinger <vapier@chromium.org> | 2016-09-15 12:16:33 +0200 |
|---|---|---|
| committer | Denys Vlasenko <vda.linux@googlemail.com> | 2016-09-15 12:16:33 +0200 |
| commit | 3a45b87ac36f60962d6d19c592813e186a9e82e6 (patch) | |
| tree | 2b3d2249ff2e558bc92a71f91339474a50a0b596 /modutils/modprobe-small.c | |
| parent | 7fa799a97d381902ab27556918722a6e2d138b9e (diff) | |
modutils: support finit_module syscall
On some systems like Chromium OS, loading modules from non-verified
filesystems is denied. Only finit_module is allowed because an open
fd is passed which can be checked against a verified location.
Change the module loading code to first attempt finit_module and if
that fails for whatever reason, fall back to the existing logic.
On x86_64, this adds ~80 bytes to modutils/modutils.o and ~68 bytes
to modutils/modprobe-small.o.
Signed-off-by: Mike Frysinger <vapier@chromium.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'modutils/modprobe-small.c')
| -rw-r--r-- | modutils/modprobe-small.c | 33 |
1 files changed, 30 insertions, 3 deletions
diff --git a/modutils/modprobe-small.c b/modutils/modprobe-small.c index 5936e48cf..a47e52234 100644 --- a/modutils/modprobe-small.c +++ b/modutils/modprobe-small.c @@ -18,9 +18,13 @@ /* After libbb.h, since it needs sys/types.h on some systems */ #include <sys/utsname.h> /* uname() */ #include <fnmatch.h> +#include <sys/syscall.h> extern int init_module(void *module, unsigned long len, const char *options); extern int delete_module(const char *module, unsigned flags); +#ifdef __NR_finit_module +# define finit_module(fd, uargs, flags) syscall(__NR_finit_module, fd, uargs, flags) +#endif /* linux/include/linux/module.h has limit of 64 chars on module names */ #undef MODULE_NAME_LEN #define MODULE_NAME_LEN 64 @@ -209,11 +213,34 @@ static int load_module(const char *fname, const char *options) int r; size_t len = MAXINT(ssize_t); char *module_image; + + if (!options) + options = ""; + dbg1_error_msg("load_module('%s','%s')", fname, options); - module_image = xmalloc_open_zipped_read_close(fname, &len); - r = (!module_image || init_module(module_image, len, options ? options : "") != 0); - free(module_image); + /* + * First we try finit_module if available. Some kernels are configured + * to only allow loading of modules off of secure storage (like a read- + * only rootfs) which needs the finit_module call. If it fails, we fall + * back to normal module loading to support compressed modules. + */ + r = 1; +# ifdef __NR_finit_module + { + int fd = open(fname, O_RDONLY | O_CLOEXEC); + if (fd >= 0) { + r = finit_module(fd, options, 0) != 0; + close(fd); + } + } +# endif + if (r != 0) { + module_image = xmalloc_open_zipped_read_close(fname, &len); + r = (!module_image || init_module(module_image, len, options) != 0); + free(module_image); + } + dbg1_error_msg("load_module:%d", r); return r; /* 0 = success */ #else |