85e7bac33b
The audit system likes to collect information about processes that end abnormally (SIGSEGV) as this may me useful intrusion detection information. This patch adds audit support to collect information when seccomp forces a task to exit because of misbehavior in a similar way. Signed-off-by: Eric Paris <eparis@redhat.com>
89 lines
1.7 KiB
C
89 lines
1.7 KiB
C
/*
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* linux/kernel/seccomp.c
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*
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* Copyright 2004-2005 Andrea Arcangeli <andrea@cpushare.com>
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*
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* This defines a simple but solid secure-computing mode.
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*/
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#include <linux/audit.h>
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#include <linux/seccomp.h>
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#include <linux/sched.h>
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#include <linux/compat.h>
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/* #define SECCOMP_DEBUG 1 */
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#define NR_SECCOMP_MODES 1
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/*
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* Secure computing mode 1 allows only read/write/exit/sigreturn.
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* To be fully secure this must be combined with rlimit
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* to limit the stack allocations too.
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*/
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static int mode1_syscalls[] = {
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__NR_seccomp_read, __NR_seccomp_write, __NR_seccomp_exit, __NR_seccomp_sigreturn,
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0, /* null terminated */
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};
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#ifdef CONFIG_COMPAT
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static int mode1_syscalls_32[] = {
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__NR_seccomp_read_32, __NR_seccomp_write_32, __NR_seccomp_exit_32, __NR_seccomp_sigreturn_32,
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0, /* null terminated */
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};
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#endif
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void __secure_computing(int this_syscall)
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{
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int mode = current->seccomp.mode;
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int * syscall;
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switch (mode) {
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case 1:
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syscall = mode1_syscalls;
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#ifdef CONFIG_COMPAT
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if (is_compat_task())
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syscall = mode1_syscalls_32;
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#endif
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do {
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if (*syscall == this_syscall)
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return;
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} while (*++syscall);
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break;
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default:
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BUG();
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}
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#ifdef SECCOMP_DEBUG
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dump_stack();
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#endif
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audit_seccomp(this_syscall);
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do_exit(SIGKILL);
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}
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long prctl_get_seccomp(void)
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{
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return current->seccomp.mode;
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}
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long prctl_set_seccomp(unsigned long seccomp_mode)
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{
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long ret;
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/* can set it only once to be even more secure */
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ret = -EPERM;
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if (unlikely(current->seccomp.mode))
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goto out;
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ret = -EINVAL;
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if (seccomp_mode && seccomp_mode <= NR_SECCOMP_MODES) {
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current->seccomp.mode = seccomp_mode;
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set_thread_flag(TIF_SECCOMP);
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#ifdef TIF_NOTSC
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disable_TSC();
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#endif
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ret = 0;
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}
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out:
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return ret;
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}
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