From: David Howells <[email protected]> Disallow the use of certain perf facilities that might allow userspace to access kernel data.
Signed-off-by: David Howells <[email protected]> Signed-off-by: Matthew Garrett <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> --- kernel/events/core.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/events/core.c b/kernel/events/core.c index 3cd13a30f732..7748c6f39992 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -10461,6 +10461,11 @@ 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)) -- 2.21.0.392.gf8f6787159e-goog
