diff options
| author | Kees Cook <keescook@chromium.org> | 2016-06-02 13:19:36 -0700 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2016-06-14 10:54:45 -0700 |
| commit | 0208b9445bc031791e589c334a93365cbad008fe (patch) | |
| tree | 588be3a0aa79df5cca66c6bbcf870bf874489e3e /arch/s390/kernel | |
| parent | 375f0183047109b98658d539db6ff22a6ac24abc (diff) | |
| download | linux-0208b9445bc031791e589c334a93365cbad008fe.tar.bz2 | |
s390/ptrace: run seccomp after ptrace
Close the hole where ptrace can change a syscall out from under seccomp.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Diffstat (limited to 'arch/s390/kernel')
| -rw-r--r-- | arch/s390/kernel/ptrace.c | 21 |
1 files changed, 9 insertions, 12 deletions
diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c index c238e9958c2a..cea17010448f 100644 --- a/arch/s390/kernel/ptrace.c +++ b/arch/s390/kernel/ptrace.c @@ -821,15 +821,6 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request, asmlinkage long do_syscall_trace_enter(struct pt_regs *regs) { - long ret = 0; - - /* Do the secure computing check first. */ - if (secure_computing(NULL)) { - /* seccomp failures shouldn't expose any additional code. */ - ret = -1; - goto out; - } - /* * The sysc_tracesys code in entry.S stored the system * call number to gprs[2]. @@ -843,7 +834,13 @@ asmlinkage long do_syscall_trace_enter(struct pt_regs *regs) * the system call and the system call restart handling. */ clear_pt_regs_flag(regs, PIF_SYSCALL); - ret = -1; + return -1; + } + + /* Do the secure computing check after ptrace. */ + if (secure_computing(NULL)) { + /* seccomp failures shouldn't expose any additional code. */ + return -1; } if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) @@ -852,8 +849,8 @@ asmlinkage long do_syscall_trace_enter(struct pt_regs *regs) audit_syscall_entry(regs->gprs[2], regs->orig_gpr2, regs->gprs[3], regs->gprs[4], regs->gprs[5]); -out: - return ret ?: regs->gprs[2]; + + return regs->gprs[2]; } asmlinkage void do_syscall_trace_exit(struct pt_regs *regs) |