diff options
Diffstat (limited to 'kernel/seccomp.c')
| -rw-r--r-- | kernel/seccomp.c | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/kernel/seccomp.c b/kernel/seccomp.c index 44af84e3bc75..49eafa463853 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -581,7 +581,8 @@ void secure_computing_strict(int this_syscall) #else #ifdef CONFIG_SECCOMP_FILTER -static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd) +static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd, + const bool recheck_after_trace) { u32 filter_ret, action; int data; @@ -613,6 +614,10 @@ static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd) goto skip; case SECCOMP_RET_TRACE: + /* We've been put in this state by the ptracer already. */ + if (recheck_after_trace) + return 0; + /* ENOSYS these calls if there is no tracer attached. */ if (!ptrace_event_enabled(current, PTRACE_EVENT_SECCOMP)) { syscall_set_return_value(current, @@ -636,6 +641,15 @@ static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd) if (this_syscall < 0) goto skip; + /* + * Recheck the syscall, since it may have changed. This + * intentionally uses a NULL struct seccomp_data to force + * a reload of all registers. This does not goto skip since + * a skip would have already been reported. + */ + if (__seccomp_filter(this_syscall, NULL, true)) + return -1; + return 0; case SECCOMP_RET_ALLOW: @@ -654,7 +668,8 @@ skip: return -1; } #else -static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd) +static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd, + const bool recheck_after_trace) { BUG(); } @@ -677,7 +692,7 @@ int __secure_computing(const struct seccomp_data *sd) __secure_computing_strict(this_syscall); /* may call do_exit */ return 0; case SECCOMP_MODE_FILTER: - return __seccomp_filter(this_syscall, sd); + return __seccomp_filter(this_syscall, sd, false); default: BUG(); } |