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Merge "liblog: remove client side permissions checking"

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am: 443b5dfea7

Change-Id: I9b99e4902ae9c5b46be58185bed524f59af3e63a
This commit is contained in:
Tom Cherry 2019-10-16 08:54:27 -07:00 committed by android-build-merger
commit ef0b0de729
1 changed files with 25 additions and 89 deletions
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114
liblog/pmsg_reader.cpp
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@ -62,58 +62,9 @@ static int pmsgAvailable(log_id_t logId) {
return -EBADF;
}
/* Determine the credentials of the caller */
static bool uid_has_log_permission(uid_t uid) {
return (uid == AID_SYSTEM) || (uid == AID_LOG) || (uid == AID_ROOT) || (uid == AID_LOGD);
}
static uid_t get_best_effective_uid() {
uid_t euid;
uid_t uid;
gid_t gid;
ssize_t i;
static uid_t last_uid = (uid_t)-1;
if (last_uid != (uid_t)-1) {
return last_uid;
}
uid = __android_log_uid();
if (uid_has_log_permission(uid)) {
return last_uid = uid;
}
euid = geteuid();
if (uid_has_log_permission(euid)) {
return last_uid = euid;
}
gid = getgid();
if (uid_has_log_permission(gid)) {
return last_uid = gid;
}
gid = getegid();
if (uid_has_log_permission(gid)) {
return last_uid = gid;
}
i = getgroups((size_t)0, NULL);
if (i > 0) {
gid_t list[i];
getgroups(i, list);
while (--i >= 0) {
if (uid_has_log_permission(list[i])) {
return last_uid = list[i];
}
}
}
return last_uid = uid;
}
static int pmsgClear(struct android_log_logger* logger __unused,
struct android_log_transport_context* transp __unused) {
if (uid_has_log_permission(get_best_effective_uid())) {
return unlink("/sys/fs/pstore/pmsg-ramoops-0");
}
errno = EPERM;
return -1;
return unlink("/sys/fs/pstore/pmsg-ramoops-0");
}
/*
@ -128,14 +79,12 @@ static int pmsgRead(struct android_log_logger_list* logger_list,
struct android_log_transport_context* transp, struct log_msg* log_msg) {
ssize_t ret;
off_t current, next;
uid_t uid;
struct __attribute__((__packed__)) {
android_pmsg_log_header_t p;
android_log_header_t l;
uint8_t prio;
} buf;
static uint8_t preread_count;
bool is_system;
memset(log_msg, 0, sizeof(*log_msg));
@ -195,37 +144,30 @@ static int pmsgRead(struct android_log_logger_list* logger_list,
((logger_list->start.tv_sec != buf.l.realtime.tv_sec) ||
(logger_list->start.tv_nsec <= buf.l.realtime.tv_nsec)))) &&
(!logger_list->pid || (logger_list->pid == buf.p.pid))) {
uid = get_best_effective_uid();
is_system = uid_has_log_permission(uid);
if (is_system || (uid == buf.p.uid)) {
char* msg = is_system ? log_msg->entry_v4.msg : log_msg->entry_v3.msg;
*msg = buf.prio;
fd = atomic_load(&transp->context.fd);
if (fd <= 0) {
return -EBADF;
}
ret = TEMP_FAILURE_RETRY(read(fd, msg + sizeof(buf.prio), buf.p.len - sizeof(buf)));
if (ret < 0) {
return -errno;
}
if (ret != (ssize_t)(buf.p.len - sizeof(buf))) {
return -EIO;
}
log_msg->entry_v4.len = buf.p.len - sizeof(buf) + sizeof(buf.prio);
log_msg->entry_v4.hdr_size =
is_system ? sizeof(log_msg->entry_v4) : sizeof(log_msg->entry_v3);
log_msg->entry_v4.pid = buf.p.pid;
log_msg->entry_v4.tid = buf.l.tid;
log_msg->entry_v4.sec = buf.l.realtime.tv_sec;
log_msg->entry_v4.nsec = buf.l.realtime.tv_nsec;
log_msg->entry_v4.lid = buf.l.id;
if (is_system) {
log_msg->entry_v4.uid = buf.p.uid;
}
return ret + sizeof(buf.prio) + log_msg->entry_v4.hdr_size;
char* msg = log_msg->entry_v4.msg;
*msg = buf.prio;
fd = atomic_load(&transp->context.fd);
if (fd <= 0) {
return -EBADF;
}
ret = TEMP_FAILURE_RETRY(read(fd, msg + sizeof(buf.prio), buf.p.len - sizeof(buf)));
if (ret < 0) {
return -errno;
}
if (ret != (ssize_t)(buf.p.len - sizeof(buf))) {
return -EIO;
}
log_msg->entry_v4.len = buf.p.len - sizeof(buf) + sizeof(buf.prio);
log_msg->entry_v4.hdr_size = sizeof(log_msg->entry_v4);
log_msg->entry_v4.pid = buf.p.pid;
log_msg->entry_v4.tid = buf.l.tid;
log_msg->entry_v4.sec = buf.l.realtime.tv_sec;
log_msg->entry_v4.nsec = buf.l.realtime.tv_nsec;
log_msg->entry_v4.lid = buf.l.id;
log_msg->entry_v4.uid = buf.p.uid;
return ret + sizeof(buf.prio) + log_msg->entry_v4.hdr_size;
}
fd = atomic_load(&transp->context.fd);
@ -273,13 +215,7 @@ ssize_t __android_log_pmsg_file_read(log_id_t logId, char prio, const char* pref
struct android_log_transport_context transp;
struct content {
struct listnode node;
union {
struct logger_entry_v4 entry;
struct logger_entry_v4 entry_v4;
struct logger_entry_v3 entry_v3;
struct logger_entry_v2 entry_v2;
struct logger_entry entry_v1;
};
struct logger_entry_v4 entry;
} * content;
struct names {
struct listnode node;