New regression test for a kernel commit:
commit bd14406b78e6daa1ea3c1673bda1ffc9efdeead0
Author: Jiri Olsa <[email protected]>
Date: Mon Aug 27 11:12:25 2018 +0200
perf/hw_breakpoint: Modify breakpoint even if the new attr has disabled set
Signed-off-by: Cyril Hrubis <[email protected]>
CC: Andy Lutomirski <[email protected]>
CC: Peter Zijlstra <[email protected]>
CC: Thomas Gleixner <[email protected]>
CC: Alexandre Chartre <[email protected]>
---
This is a follow up for the ptrace08 fixes.
runtest/syscalls | 1 +
testcases/kernel/syscalls/ptrace/.gitignore | 1 +
testcases/kernel/syscalls/ptrace/ptrace10.c | 86 +++++++++++++++++++++
3 files changed, 88 insertions(+)
create mode 100644 testcases/kernel/syscalls/ptrace/ptrace10.c
diff --git a/runtest/syscalls b/runtest/syscalls
index 398145f65..163471bcd 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -993,6 +993,7 @@ ptrace05 ptrace05
ptrace07 ptrace07
ptrace08 ptrace08
ptrace09 ptrace09
+ptrace10 ptrace10
pwrite01 pwrite01
pwrite02 pwrite02
diff --git a/testcases/kernel/syscalls/ptrace/.gitignore b/testcases/kernel/syscalls/ptrace/.gitignore
index 7639e1a9f..7ee3b3c47 100644
--- a/testcases/kernel/syscalls/ptrace/.gitignore
+++ b/testcases/kernel/syscalls/ptrace/.gitignore
@@ -5,3 +5,4 @@
/ptrace07
/ptrace08
/ptrace09
+/ptrace10
diff --git a/testcases/kernel/syscalls/ptrace/ptrace10.c b/testcases/kernel/syscalls/ptrace/ptrace10.c
new file mode 100644
index 000000000..b5d6b9f8f
--- /dev/null
+++ b/testcases/kernel/syscalls/ptrace/ptrace10.c
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2020 Cyril Hrubis <[email protected]>
+ *
+ * After fix for CVE-2018-1000199 (see ptrace08.c) subsequent calls to POKEUSER
+ * for x86 debug registers were ignored silently.
+ *
+ * This is a regression test for commit:
+ *
+ * commit bd14406b78e6daa1ea3c1673bda1ffc9efdeead0
+ * Author: Jiri Olsa <[email protected]>
+ * Date: Mon Aug 27 11:12:25 2018 +0200
+ *
+ * perf/hw_breakpoint: Modify breakpoint even if the new attr has disabled set
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stddef.h>
+#include <sys/ptrace.h>
+#include <sys/user.h>
+#include <signal.h>
+#include "tst_test.h"
+
+#if defined(__i386__) || defined(__x86_64__)
+
+static pid_t child_pid;
+
+static void child_main(void)
+{
+ raise(SIGSTOP);
+ exit(0);
+}
+
+static void run(void)
+{
+ int status;
+ unsigned long addr;
+
+ child_pid = SAFE_FORK();
+
+ if (!child_pid)
+ child_main();
+
+ if (SAFE_WAITPID(child_pid, &status, WUNTRACED) != child_pid)
+ tst_brk(TBROK, "Received event from unexpected PID");
+
+ SAFE_PTRACE(PTRACE_ATTACH, child_pid, NULL, NULL);
+ SAFE_PTRACE(PTRACE_POKEUSER, child_pid,
+ (void *)offsetof(struct user, u_debugreg[0]), (void *)1);
+ SAFE_PTRACE(PTRACE_POKEUSER, child_pid,
+ (void *)offsetof(struct user, u_debugreg[0]), (void *)2);
+
+ addr = ptrace(PTRACE_PEEKUSER, child_pid,
+ (void*)offsetof(struct user, u_debugreg[0]), NULL);
+
+ if (addr == 2)
+ tst_res(TPASS, "The rd0 was set on second PTRACE_POKEUSR");
+ else
+ tst_res(TFAIL, "The rd0 wasn't set on second PTRACE_POKEUSER");
+
+ SAFE_PTRACE(PTRACE_DETACH, child_pid, NULL, NULL);
+ SAFE_KILL(child_pid, SIGCONT);
+ child_pid = 0;
+ tst_reap_children();
+}
+
+static void cleanup(void)
+{
+ /* Main process terminated by tst_brk() with child still paused */
+ if (child_pid)
+ SAFE_KILL(child_pid, SIGKILL);
+}
+
+static struct tst_test test = {
+ .test_all = run,
+ .cleanup = cleanup,
+ .forks_child = 1,
+ .tags = (const struct tst_tag[]) {
+ {"linux-git", "bd14406b78e6"},
+ {}
+ }
+};
+#else
+TST_TEST_TCONF("This test is only supported on x86 systems");
+#endif
--
2.26.2
Hi,
the code looks good, though it might make sense to simply integrate the
check into ptrace08. Just 6 extra lines in the existing test should
achieve the same coverage.
It also seems the bug existed long before the CVE 2018-1000199 fix
because the test fails on vulnerable kernels as well.
Anyway, if you prefer to keep the patch as is:
Reviewed-by: Martin Doucha <[email protected]>
On 04. 09. 20 20:00, Cyril Hrubis wrote:
> New regression test for a kernel commit:
>
> commit bd14406b78e6daa1ea3c1673bda1ffc9efdeead0
> Author: Jiri Olsa <[email protected]>
> Date: Mon Aug 27 11:12:25 2018 +0200
>
> perf/hw_breakpoint: Modify breakpoint even if the new attr has disabled set
>
> Signed-off-by: Cyril Hrubis <[email protected]>
> CC: Andy Lutomirski <[email protected]>
> CC: Peter Zijlstra <[email protected]>
> CC: Thomas Gleixner <[email protected]>
> CC: Alexandre Chartre <[email protected]>
> ---
--
Martin Doucha [email protected]
QA Engineer for Software Maintenance
SUSE LINUX, s.r.o.
CORSO IIa
Krizikova 148/34
186 00 Prague 8
Czech Republic