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			Follow the inclusive terminology from the "Conscious Language in your Open Source Projects" guidelines [*] and replace the words "whitelist" appropriately. [*] https://github.com/conscious-lang/conscious-lang-docs/blob/main/faq.md Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <20210205171817.2108907-3-philmd@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
		
			
				
	
	
		
			176 lines
		
	
	
		
			4.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			176 lines
		
	
	
		
			4.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Seccomp sandboxing for virtiofsd
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|  *
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|  * Copyright (C) 2019 Red Hat, Inc.
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|  *
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|  * SPDX-License-Identifier: GPL-2.0-or-later
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|  */
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| 
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| #include "qemu/osdep.h"
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| #include "passthrough_seccomp.h"
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| #include "fuse_i.h"
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| #include "fuse_log.h"
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| #include <seccomp.h>
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| 
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| /* Bodge for libseccomp 2.4.2 which broke ppoll */
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| #if !defined(__SNR_ppoll) && defined(__SNR_brk)
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| #ifdef __NR_ppoll
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| #define __SNR_ppoll __NR_ppoll
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| #else
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| #define __SNR_ppoll __PNR_ppoll
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| #endif
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| #endif
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| 
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| static const int syscall_allowlist[] = {
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|     /* TODO ireg sem*() syscalls */
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|     SCMP_SYS(brk),
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|     SCMP_SYS(capget), /* For CAP_FSETID */
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|     SCMP_SYS(capset),
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|     SCMP_SYS(clock_gettime),
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|     SCMP_SYS(clone),
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| #ifdef __NR_clone3
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|     SCMP_SYS(clone3),
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| #endif
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|     SCMP_SYS(close),
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|     SCMP_SYS(copy_file_range),
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|     SCMP_SYS(dup),
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|     SCMP_SYS(eventfd2),
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|     SCMP_SYS(exit),
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|     SCMP_SYS(exit_group),
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|     SCMP_SYS(fallocate),
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|     SCMP_SYS(fchdir),
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|     SCMP_SYS(fchmod),
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|     SCMP_SYS(fchmodat),
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|     SCMP_SYS(fchownat),
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|     SCMP_SYS(fcntl),
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|     SCMP_SYS(fdatasync),
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|     SCMP_SYS(fgetxattr),
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|     SCMP_SYS(flistxattr),
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|     SCMP_SYS(flock),
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|     SCMP_SYS(fremovexattr),
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|     SCMP_SYS(fsetxattr),
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|     SCMP_SYS(fstat),
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|     SCMP_SYS(fstatfs),
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|     SCMP_SYS(fsync),
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|     SCMP_SYS(ftruncate),
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|     SCMP_SYS(futex),
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|     SCMP_SYS(getdents),
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|     SCMP_SYS(getdents64),
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|     SCMP_SYS(getegid),
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|     SCMP_SYS(geteuid),
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|     SCMP_SYS(getpid),
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|     SCMP_SYS(gettid),
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|     SCMP_SYS(gettimeofday),
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|     SCMP_SYS(getxattr),
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|     SCMP_SYS(linkat),
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|     SCMP_SYS(listxattr),
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|     SCMP_SYS(lseek),
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|     SCMP_SYS(_llseek), /* For POWER */
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|     SCMP_SYS(madvise),
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|     SCMP_SYS(mkdirat),
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|     SCMP_SYS(mknodat),
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|     SCMP_SYS(mmap),
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|     SCMP_SYS(mprotect),
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|     SCMP_SYS(mremap),
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|     SCMP_SYS(munmap),
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|     SCMP_SYS(newfstatat),
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|     SCMP_SYS(statx),
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|     SCMP_SYS(open),
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|     SCMP_SYS(openat),
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|     SCMP_SYS(ppoll),
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|     SCMP_SYS(prctl), /* TODO restrict to just PR_SET_NAME? */
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|     SCMP_SYS(preadv),
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|     SCMP_SYS(pread64),
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|     SCMP_SYS(pwritev),
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|     SCMP_SYS(pwrite64),
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|     SCMP_SYS(read),
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|     SCMP_SYS(readlinkat),
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|     SCMP_SYS(recvmsg),
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|     SCMP_SYS(renameat),
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|     SCMP_SYS(renameat2),
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|     SCMP_SYS(removexattr),
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|     SCMP_SYS(restart_syscall),
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|     SCMP_SYS(rt_sigaction),
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|     SCMP_SYS(rt_sigprocmask),
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|     SCMP_SYS(rt_sigreturn),
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|     SCMP_SYS(sched_getattr),
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|     SCMP_SYS(sched_setattr),
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|     SCMP_SYS(sendmsg),
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|     SCMP_SYS(setresgid),
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|     SCMP_SYS(setresuid),
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| #ifdef __NR_setresgid32
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|     SCMP_SYS(setresgid32),
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| #endif
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| #ifdef __NR_setresuid32
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|     SCMP_SYS(setresuid32),
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| #endif
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|     SCMP_SYS(set_robust_list),
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|     SCMP_SYS(setxattr),
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|     SCMP_SYS(symlinkat),
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|     SCMP_SYS(time), /* Rarely needed, except on static builds */
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|     SCMP_SYS(tgkill),
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|     SCMP_SYS(unlinkat),
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|     SCMP_SYS(unshare),
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|     SCMP_SYS(utimensat),
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|     SCMP_SYS(write),
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|     SCMP_SYS(writev),
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| };
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| 
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| /* Syscalls used when --syslog is enabled */
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| static const int syscall_allowlist_syslog[] = {
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|     SCMP_SYS(send),
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|     SCMP_SYS(sendto),
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| };
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| 
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| static void add_allowlist(scmp_filter_ctx ctx, const int syscalls[], size_t len)
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| {
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|     size_t i;
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| 
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|     for (i = 0; i < len; i++) {
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|         if (seccomp_rule_add(ctx, SCMP_ACT_ALLOW, syscalls[i], 0) != 0) {
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|             fuse_log(FUSE_LOG_ERR, "seccomp_rule_add syscall %d failed\n",
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|                      syscalls[i]);
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|             exit(1);
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|         }
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|     }
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| }
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| 
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| void setup_seccomp(bool enable_syslog)
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| {
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|     scmp_filter_ctx ctx;
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| 
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| #ifdef SCMP_ACT_KILL_PROCESS
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|     ctx = seccomp_init(SCMP_ACT_KILL_PROCESS);
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|     /* Handle a newer libseccomp but an older kernel */
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|     if (!ctx && errno == EOPNOTSUPP) {
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|         ctx = seccomp_init(SCMP_ACT_TRAP);
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|     }
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| #else
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|     ctx = seccomp_init(SCMP_ACT_TRAP);
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| #endif
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|     if (!ctx) {
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|         fuse_log(FUSE_LOG_ERR, "seccomp_init() failed\n");
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|         exit(1);
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|     }
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| 
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|     add_allowlist(ctx, syscall_allowlist, G_N_ELEMENTS(syscall_allowlist));
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|     if (enable_syslog) {
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|         add_allowlist(ctx, syscall_allowlist_syslog,
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|                       G_N_ELEMENTS(syscall_allowlist_syslog));
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|     }
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| 
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|     /* libvhost-user calls this for post-copy migration, we don't need it */
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|     if (seccomp_rule_add(ctx, SCMP_ACT_ERRNO(ENOSYS),
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|                          SCMP_SYS(userfaultfd), 0) != 0) {
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|         fuse_log(FUSE_LOG_ERR, "seccomp_rule_add userfaultfd failed\n");
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|         exit(1);
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|     }
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| 
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|     if (seccomp_load(ctx) < 0) {
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|         fuse_log(FUSE_LOG_ERR, "seccomp_load() failed\n");
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|         exit(1);
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|     }
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| 
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|     seccomp_release(ctx);
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| }
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