57 lines
1.1 KiB
C
57 lines
1.1 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/seccomp.h>
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#include <linux/sched.h>
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/* #define SECCOMP_DEBUG 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 TIF_32BIT
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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 TIF_32BIT
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if (test_thread_flag(TIF_32BIT))
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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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do_exit(SIGKILL);
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}
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