Close the hole where ptrace can change a syscall out from under seccomp.
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
---
arch/arm64/kernel/ptrace.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 6e2cf046615d..602316c97a47 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -1246,13 +1246,13 @@ static void tracehook_report_syscall(struct pt_regs *regs,
asmlinkage int syscall_trace_enter(struct pt_regs *regs)
{
- /* Do the secure computing check first; failures should be fast. */
- if (secure_computing(NULL) == -1)
- return -1;
-
if (test_thread_flag(TIF_SYSCALL_TRACE))
tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
+ /* Do the secure computing after ptrace; failures should be fast. */
+ if (secure_computing(NULL) == -1)
+ return -1;
+
if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
trace_sys_enter(regs, regs->syscallno);
--
2.7.4
