[PATCH 25/27] Lock down perf
From: Matthew Garrett <hidden>
Date: 2019-02-28 23:13:16
Also in:
lkml
Subsystem:
performance events subsystem, the rest · Maintainers:
Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds
From: David Howells <dhowells@redhat.com> Disallow the use of certain perf facilities that might allow userspace to access kernel data. Signed-off-by: David Howells <dhowells@redhat.com> --- kernel/events/core.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 26d6edab051a..4265ce43bca4 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c@@ -10477,6 +10477,11 @@ SYSCALL_DEFINE5(perf_event_open, return -EINVAL; } + if ((attr.sample_type & PERF_SAMPLE_REGS_INTR) && + kernel_is_locked_down("PERF_SAMPLE_REGS_INTR")) + /* REGS_INTR can leak data, lockdown must prevent this */ + return -EPERM; + /* Only privileged users can get physical addresses */ if ((attr.sample_type & PERF_SAMPLE_PHYS_ADDR) && perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
--
2.21.0.352.gf09ad66450-goog