diff --git a/pkg/sentry/syscalls/linux/sys_rlimit.go b/pkg/sentry/syscalls/linux/sys_rlimit.go index e08c333d6..d5d5b6959 100644 --- a/pkg/sentry/syscalls/linux/sys_rlimit.go +++ b/pkg/sentry/syscalls/linux/sys_rlimit.go @@ -197,7 +197,7 @@ func Prlimit64(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sys // saved set user IDs of the target process must match the real user ID of // the caller and the real, effective, and saved set group IDs of the // target process must match the real group ID of the caller." - if !t.HasCapabilityIn(linux.CAP_SYS_RESOURCE, t.PIDNamespace().UserNamespace()) { + if ot != t && !t.HasCapabilityIn(linux.CAP_SYS_RESOURCE, t.PIDNamespace().UserNamespace()) { cred, tcred := t.Credentials(), ot.Credentials() if cred.RealKUID != tcred.RealKUID || cred.RealKUID != tcred.EffectiveKUID || diff --git a/test/syscalls/linux/uidgid.cc b/test/syscalls/linux/uidgid.cc index 6218fbce1..ff66a79f4 100644 --- a/test/syscalls/linux/uidgid.cc +++ b/test/syscalls/linux/uidgid.cc @@ -14,6 +14,7 @@ #include #include +#include #include #include @@ -249,6 +250,17 @@ TEST(UidGidRootTest, Setgroups) { SyscallFailsWithErrno(EFAULT)); } +TEST(UidGidRootTest, Setuid_prlimit) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(IsRoot())); + + // Change our UID. + EXPECT_THAT(seteuid(65534), SyscallSucceeds()); + + // Despite the UID change, we should be able to get our own limits. + struct rlimit rl = {}; + ASSERT_THAT(prlimit(0, RLIMIT_NOFILE, NULL, &rl), SyscallSucceeds()); +} + } // namespace } // namespace testing