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Merge "logd: Use Minijail for privilege dropping."

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Treehugger Robot 2016-07-20 15:02:17 +00:00 • committed by Gerrit Code Review
commit d3dfd95728
2 changed files with 13 additions and 39 deletions
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3
logd/Android.mk
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@ -28,7 +28,8 @@ LOCAL_SHARED_LIBRARIES := \
liblog \ liblog \
libcutils \ libcutils \
libbase \ libbase \
libpackagelistparser libpackagelistparser \
libminijail
# This is what we want to do: # This is what we want to do:
# event_logtags = $(shell \ # event_logtags = $(shell \

49
logd/main.cpp
View file

@ -36,12 +36,15 @@
#include <cstdbool> #include <cstdbool>
#include <memory> #include <memory>
#include <android-base/macros.h>
#include <cutils/properties.h> #include <cutils/properties.h>
#include <cutils/sched_policy.h> #include <cutils/sched_policy.h>
#include <cutils/sockets.h> #include <cutils/sockets.h>
#include <libminijail.h>
#include <log/event_tag_map.h> #include <log/event_tag_map.h>
#include <packagelistparser/packagelistparser.h> #include <packagelistparser/packagelistparser.h>
#include <private/android_filesystem_config.h> #include <private/android_filesystem_config.h>
#include <scoped_minijail.h>
#include <utils/threads.h> #include <utils/threads.h>
#include "CommandListener.h" #include "CommandListener.h"
@ -58,14 +61,14 @@
'>' '>'
// //
// The service is designed to be run by init, it does not respond well // The service is designed to be run by init, it does not respond well
// to starting up manually. When starting up manually the sockets will // to starting up manually. When starting up manually the sockets will
// fail to open typically for one of the following reasons: // fail to open typically for one of the following reasons:
// EADDRINUSE if logger is running. // EADDRINUSE if logger is running.
// EACCESS if started without precautions (below) // EACCESS if started without precautions (below)
// //
// Here is a cookbook procedure for starting up logd manually assuming // Here is a cookbook procedure for starting up logd manually assuming
// init is out of the way, pedantically all permissions and selinux // init is out of the way, pedantically all permissions and SELinux
// security is put back in place: // security is put back in place:
// //
// setenforce 0 // setenforce 0
@ -102,43 +105,13 @@ static int drop_privs() {
return -1; return -1;
} }
if (prctl(PR_SET_KEEPCAPS, 1) < 0) {
return -1;
}
gid_t groups[] = { AID_READPROC }; gid_t groups[] = { AID_READPROC };
ScopedMinijail j(minijail_new());
if (setgroups(sizeof(groups) / sizeof(groups[0]), groups) == -1) { minijail_set_supplementary_gids(j.get(), arraysize(groups), groups);
return -1; minijail_change_uid(j.get(), AID_LOGD);
} minijail_change_gid(j.get(), AID_LOGD);
minijail_use_caps(j.get(), CAP_TO_MASK(CAP_SYSLOG) | CAP_TO_MASK(CAP_AUDIT_CONTROL));
if (setgid(AID_LOGD) != 0) { minijail_enter(j.get());
return -1;
}
if (setuid(AID_LOGD) != 0) {
return -1;
}
struct __user_cap_header_struct capheader;
struct __user_cap_data_struct capdata[2];
memset(&capheader, 0, sizeof(capheader));
memset(&capdata, 0, sizeof(capdata));
capheader.version = _LINUX_CAPABILITY_VERSION_3;
capheader.pid = 0;
capdata[CAP_TO_INDEX(CAP_SYSLOG)].permitted = CAP_TO_MASK(CAP_SYSLOG);
capdata[CAP_TO_INDEX(CAP_AUDIT_CONTROL)].permitted |= CAP_TO_MASK(CAP_AUDIT_CONTROL);
capdata[0].effective = capdata[0].permitted;
capdata[1].effective = capdata[1].permitted;
capdata[0].inheritable = 0;
capdata[1].inheritable = 0;
if (capset(&capheader, &capdata[0]) < 0) {
return -1;
}
return 0; return 0;
} }