Bug 1320085 - Allow the getrlimit-equivalent subset of prlimit64. r?tedd
This applies only to content processes, where we already allow getrlimit
(but not setrlimit). The rule added here does not allow using prlimit64
to set any resource limits or interact with any other process.
MozReview-Commit-ID: nMry3t6QPj
--- a/security/sandbox/linux/SandboxFilter.cpp
+++ b/security/sandbox/linux/SandboxFilter.cpp
@@ -711,16 +711,28 @@ public:
return Allow();
CASES_FOR_getrlimit:
case __NR_clock_getres:
CASES_FOR_getresuid:
CASES_FOR_getresgid:
return Allow();
+ case __NR_prlimit64: {
+ // Allow only the getrlimit() use case. (glibc seems to use
+ // only pid 0 to indicate the current process; pid == getpid()
+ // is equivalent and could also be allowed if needed.)
+ Arg<pid_t> pid(0);
+ // This is really a const struct ::rlimit*, but Arg<> doesn't
+ // work with pointers, only integer types.
+ Arg<uintptr_t> new_limit(2);
+ return If(AllOf(pid == 0, new_limit == 0), Allow())
+ .Else(InvalidSyscall());
+ }
+
case __NR_umask:
case __NR_kill:
case __NR_wait4:
#ifdef __NR_waitpid
case __NR_waitpid:
#endif
#ifdef __NR_arch_prctl
case __NR_arch_prctl: