init/service.cpp: fix access check for console
Commit 9596d2b95d3137c476be4b7c15c47c62ef5cbe09 changes how
availability of console is checked by only checking access bits for
the console device. However, in cases where there is no console it
defaults to /dev/console. This device is always enumerated by tty
driver (i.e. file and access bits may be correct), but it doesn't
always map to an underlying console driver. Because the lookup for the
underlying console driver happens during the open system call, checking
only the access bits is not sufficient and need to make sure open
system call is successful, we can safely close the FD afterwards to
avoid FD leaks.
Test: boot device and check console svc doesn't continuously restart
Bug: 33691649
Change-Id: Ia51a8a2f56c345b70db55e95f61a057a98b52895
diff --git a/init/service.cpp b/init/service.cpp
index 7cff348..0f7f62f 100644
--- a/init/service.cpp
+++ b/init/service.cpp
@@ -582,12 +582,15 @@
console_ = default_console;
}
- bool have_console = (access(console_.c_str(), R_OK | W_OK) != -1);
- if (!have_console) {
- PLOG(ERROR) << "service '" << name_ << "' cannot gain read/write access to console '" << console_ << "'";
+ // Make sure that open call succeeds to ensure a console driver is
+ // properly registered for the device node
+ int console_fd = open(console_.c_str(), O_RDWR | O_CLOEXEC);
+ if (console_fd < 0) {
+ PLOG(ERROR) << "service '" << name_ << "' couldn't open console '" << console_ << "'";
flags_ |= SVC_DISABLED;
return false;
}
+ close(console_fd);
}
struct stat sb;