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| author | Jorge Lucangeli Obes <jorgelo@google.com> | 2016-07-14 14:50:14 -0400 |
|---|---|---|
| committer | Jorge Lucangeli Obes <jorgelo@google.com> | 2016-07-15 10:16:59 -0400 |
| commit | c96f53e2fe7e67bd8a412575355e1b816f0aceaf (patch) | |
| tree | 2c6e3f3d7e474f0ffa507c000248dbb986b0b3b5 /sdcard | |
| parent | a17427cb1e9caaeb4dde7184b05dfa4b3b1f7172 (diff) | |
| download | core-c96f53e2fe7e67bd8a412575355e1b816f0aceaf.tar.gz | |
Use Minijail for privilege dropping.
Having so many copies of privilege-dropping code leads to errors.
De-duplicate this code and use Minijail for it.
Bug: 30156807
Change-Id: I36c85962b913a12efe5648a23cbacc5bcbb3853c
Diffstat (limited to 'sdcard')
| -rw-r--r-- | sdcard/Android.mk | 2 | ||||
| -rw-r--r-- | sdcard/sdcard.cpp | 24 |
2 files changed, 15 insertions, 11 deletions
diff --git a/sdcard/Android.mk b/sdcard/Android.mk index f87e2d5ea..992b51c6f 100644 --- a/sdcard/Android.mk +++ b/sdcard/Android.mk @@ -5,7 +5,7 @@ include $(CLEAR_VARS) LOCAL_SRC_FILES := sdcard.cpp fuse.cpp LOCAL_MODULE := sdcard LOCAL_CFLAGS := -Wall -Wno-unused-parameter -Werror -LOCAL_SHARED_LIBRARIES := libbase liblog libcutils libpackagelistparser +LOCAL_SHARED_LIBRARIES := libbase liblog libcutils libminijail libpackagelistparser LOCAL_SANITIZE := integer LOCAL_CLANG := true diff --git a/sdcard/sdcard.cpp b/sdcard/sdcard.cpp index dd0c433e2..e82f29ed4 100644 --- a/sdcard/sdcard.cpp +++ b/sdcard/sdcard.cpp @@ -36,6 +36,9 @@ #include <cutils/multiuser.h> #include <packagelistparser/packagelistparser.h> +#include <libminijail.h> +#include <scoped_minijail.h> + #include <private/android_filesystem_config.h> // README @@ -204,6 +207,15 @@ static int fuse_setup(struct fuse* fuse, gid_t gid, mode_t mask) { return 0; } +static void drop_privs(uid_t uid, gid_t gid) { + ScopedMinijail j(minijail_new()); + minijail_set_supplementary_gids(j.get(), sizeof(kGroups) / sizeof(kGroups[0]), kGroups); + minijail_change_gid(j.get(), gid); + minijail_change_uid(j.get(), uid); + /* minijail_enter() will abort if priv-dropping fails. */ + minijail_enter(j.get()); +} + static void* start_handler(void* data) { struct fuse_handler* handler = static_cast<fuse_handler*>(data); handle_fuse_requests(handler); @@ -299,16 +311,8 @@ static void run(const char* source_path, const char* label, uid_t uid, } } - /* Drop privs. */ - if (setgroups(sizeof(kGroups) / sizeof(kGroups[0]), kGroups) < 0) { - PLOG(FATAL) << "cannot setgroups"; - } - if (setgid(gid) < 0) { - PLOG(FATAL) << "cannot setgid"; - } - if (setuid(uid) < 0) { - PLOG(FATAL) << "cannot setuid"; - } + // Will abort if priv-dropping fails. + drop_privs(uid, gid); if (multi_user) { fs_prepare_dir(global.obb_path, 0775, uid, gid); |