Merge pull request #2281 from brauner/2018-04-15/seccomp_fixes

seccomp: handle arch inversion - The Architecture Strikes Back

doc/lxc-execute.sgml.in

@@ -50,6 +50,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
     <cmdsynopsis>
       <command>lxc-execute</command>
       <arg choice="req">-n <replaceable>name</replaceable></arg>
+      <arg choice="opt">-d</arg>
       <arg choice="opt">-f <replaceable>config_file</replaceable></arg>
       <arg choice="opt">-s KEY=VAL</arg>
       <arg choice="opt">-- <replaceable>command</replaceable></arg>
@@ -124,6 +125,20 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 	  </para>
 	</listitem>
       </varlistentry>
+
+      <varlistentry>
+	<term>
+	  <option>-d, --daemon</option>
+	</term>
+	<listitem>
+	  <para>
+	    Run the container as a daemon. As the container has no
+	    more tty, if an error occurs nothing will be displayed,
+	    the log file can be used to check the error.
+	  </para>
+	</listitem>
+      </varlistentry>
+
       <varlistentry>
 	<term><option>--</option></term>
 	<listitem>

src/lxc/seccomp.c

@@ -319,7 +319,7 @@ int get_hostarch(void)
 	return lxc_seccomp_arch_unknown;
 }
 
-scmp_filter_ctx get_new_ctx(enum lxc_hostarch_t n_arch, uint32_t default_policy_action)
+scmp_filter_ctx get_new_ctx(enum lxc_hostarch_t n_arch, uint32_t default_policy_action, bool *needs_merge)
 {
 	scmp_filter_ctx ctx;
 	int ret;
@@ -397,7 +397,10 @@ scmp_filter_ctx get_new_ctx(enum lxc_hostarch_t n_arch, uint32_t default_policy_
 			return NULL;
 		}
 		TRACE("Removed native arch from main seccomp context");
+
+		*needs_merge = true;
 	} else {
+		*needs_merge = false;
 		TRACE("Arch %d already present in main seccomp context", (int)n_arch);
 	}
 
@@ -490,13 +493,16 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
 {
 	char *p;
 	int ret;
-	scmp_filter_ctx compat_ctx[2] = {NULL, NULL};
 	bool blacklist = false;
 	uint32_t default_policy_action = -1, default_rule_action = -1;
 	enum lxc_hostarch_t native_arch = get_hostarch(),
 			    cur_rule_arch = native_arch;
-	uint32_t compat_arch[2] = {SCMP_ARCH_NATIVE, SCMP_ARCH_NATIVE};
 	struct seccomp_v2_rule rule;
+	struct scmp_ctx_info {
+		uint32_t architectures[3];
+		scmp_filter_ctx contexts[3];
+		bool needs_merge[3];
+	} ctx;
 
 	if (strncmp(line, "blacklist", 9) == 0)
 		blacklist = true;
@@ -524,54 +530,115 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
 			default_rule_action = SCMP_ACT_ALLOW;
 	}
 
+	memset(&ctx, 0, sizeof(ctx));
+	ctx.architectures[0] = SCMP_ARCH_NATIVE;
+	ctx.architectures[1] = SCMP_ARCH_NATIVE;
+	ctx.architectures[2] = SCMP_ARCH_NATIVE;
 	if (native_arch == lxc_seccomp_arch_amd64) {
 		cur_rule_arch = lxc_seccomp_arch_all;
-		compat_arch[0] = SCMP_ARCH_X86;
-		compat_ctx[0] = get_new_ctx(lxc_seccomp_arch_i386,
-				default_policy_action);
-		compat_arch[1] = SCMP_ARCH_X32;
-		compat_ctx[1] = get_new_ctx(lxc_seccomp_arch_x32,
-				default_policy_action);
-		if (!compat_ctx[0] || !compat_ctx[1])
+
+		ctx.architectures[0] = SCMP_ARCH_X86;
+		ctx.contexts[0] = get_new_ctx(lxc_seccomp_arch_i386,
+					      default_policy_action,
+					      &ctx.needs_merge[0]);
+		if (!ctx.contexts[0])
+			goto bad;
+
+		ctx.architectures[1] = SCMP_ARCH_X32;
+		ctx.contexts[1] = get_new_ctx(lxc_seccomp_arch_x32,
+					      default_policy_action,
+					      &ctx.needs_merge[1]);
+		if (!ctx.contexts[1])
+			goto bad;
+
+		ctx.architectures[2] = SCMP_ARCH_X86_64;
+		ctx.contexts[2] = get_new_ctx(lxc_seccomp_arch_amd64,
+					      default_policy_action,
+					      &ctx.needs_merge[2]);
+		if (!ctx.contexts[2])
 			goto bad;
 #ifdef SCMP_ARCH_PPC
 	} else if (native_arch == lxc_seccomp_arch_ppc64) {
 		cur_rule_arch = lxc_seccomp_arch_all;
-		compat_arch[0] = SCMP_ARCH_PPC;
-		compat_ctx[0] = get_new_ctx(lxc_seccomp_arch_ppc,
-				default_policy_action);
-		if (!compat_ctx[0])
+
+		ctx.architectures[0] = SCMP_ARCH_PPC;
+		ctx.contexts[0] = get_new_ctx(lxc_seccomp_arch_ppc,
+					      default_policy_action,
+					      &ctx.needs_merge[0]);
+		if (!ctx.contexts[0])
+			goto bad;
+
+		ctx.architectures[2] = SCMP_ARCH_PPC64;
+		ctx.contexts[2] = get_new_ctx(lxc_seccomp_arch_ppc64,
+					      default_policy_action,
+					      &ctx.needs_merge[2]);
+		if (!ctx.contexts[2])
 			goto bad;
 #endif
 #ifdef SCMP_ARCH_ARM
 	} else if (native_arch == lxc_seccomp_arch_arm64) {
 		cur_rule_arch = lxc_seccomp_arch_all;
-		compat_arch[0] = SCMP_ARCH_ARM;
-		compat_ctx[0] = get_new_ctx(lxc_seccomp_arch_arm,
-				default_policy_action);
-		if (!compat_ctx[0])
+
+		ctx.architectures[0] = SCMP_ARCH_ARM;
+		ctx.contexts[0] = get_new_ctx(lxc_seccomp_arch_arm,
+					      default_policy_action,
+					      &ctx.needs_merge[0]);
+		if (!ctx.contexts[0])
+			goto bad;
+
+		ctx.architectures[2] = SCMP_ARCH_AARCH64;
+		ctx.contexts[2] = get_new_ctx(lxc_seccomp_arch_arm64,
+					      default_policy_action,
+					      &ctx.needs_merge[2]);
+		if (!ctx.contexts[2])
 			goto bad;
 #endif
 #ifdef SCMP_ARCH_MIPS
 	} else if (native_arch == lxc_seccomp_arch_mips64) {
 		cur_rule_arch = lxc_seccomp_arch_all;
-		compat_arch[0] = SCMP_ARCH_MIPS;
-		compat_arch[1] = SCMP_ARCH_MIPS64N32;
-		compat_ctx[0] = get_new_ctx(lxc_seccomp_arch_mips,
-				default_policy_action);
-		compat_ctx[1] = get_new_ctx(lxc_seccomp_arch_mips64n32,
-				default_policy_action);
-		if (!compat_ctx[0] || !compat_ctx[1])
+
+		ctx.architectures[0] = SCMP_ARCH_MIPS;
+		ctx.contexts[0] = get_new_ctx(lxc_seccomp_arch_mips,
+					      default_policy_action,
+					      &ctx.needs_merge[0]);
+		if (!ctx.contexts[0])
+			goto bad;
+
+		ctx.architectures[1] = SCMP_ARCH_MIPS64N32;
+		ctx.contexts[1] = get_new_ctx(lxc_seccomp_arch_mips64n32,
+					      default_policy_action,
+					      &ctx.needs_merge[1]);
+		if (!ctx.contexts[1])
+			goto bad;
+
+		ctx.architectures[2] = SCMP_ARCH_MIPS64;
+		ctx.contexts[2] = get_new_ctx(lxc_seccomp_arch_mips64,
+					      default_policy_action,
+					      &ctx.needs_merge[2]);
+		if (!ctx.contexts[2])
 			goto bad;
 	} else if (native_arch == lxc_seccomp_arch_mipsel64) {
 		cur_rule_arch = lxc_seccomp_arch_all;
-		compat_arch[0] = SCMP_ARCH_MIPSEL;
-		compat_arch[1] = SCMP_ARCH_MIPSEL64N32;
-		compat_ctx[0] = get_new_ctx(lxc_seccomp_arch_mipsel,
-				default_policy_action);
-		compat_ctx[1] = get_new_ctx(lxc_seccomp_arch_mipsel64n32,
-				default_policy_action);
-		if (!compat_ctx[0] || !compat_ctx[1])
+
+		ctx.architectures[0] = SCMP_ARCH_MIPSEL;
+		ctx.contexts[0] = get_new_ctx(lxc_seccomp_arch_mipsel,
+					      default_policy_action,
+					      &ctx.needs_merge[0]);
+		if (!ctx.contexts[0])
+			goto bad;
+
+		ctx.architectures[1] = SCMP_ARCH_MIPSEL64N32;
+		ctx.contexts[1] = get_new_ctx(lxc_seccomp_arch_mipsel64n32,
+					      default_policy_action,
+					      &ctx.needs_merge[1]);
+		if (!ctx.contexts[1])
+			goto bad;
+
+		ctx.architectures[2] = SCMP_ARCH_MIPSEL64;
+		ctx.contexts[2] = get_new_ctx(lxc_seccomp_arch_mipsel64,
+					      default_policy_action,
+					      &ctx.needs_merge[2]);
+		if (!ctx.contexts[2])
 			goto bad;
 #endif
 	}
@@ -606,7 +673,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
 			if (strcmp(line, "[x86]") == 0 ||
 			    strcmp(line, "[X86]") == 0) {
 				if (native_arch != lxc_seccomp_arch_i386 &&
-						native_arch != lxc_seccomp_arch_amd64) {
+				    native_arch != lxc_seccomp_arch_amd64) {
 					cur_rule_arch = lxc_seccomp_arch_unknown;
 					continue;
 				}
@@ -633,7 +700,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
 			else if (strcmp(line, "[arm]") == 0 ||
 				 strcmp(line, "[ARM]") == 0) {
 				if (native_arch != lxc_seccomp_arch_arm &&
-						native_arch != lxc_seccomp_arch_arm64) {
+				    native_arch != lxc_seccomp_arch_arm64) {
 					cur_rule_arch = lxc_seccomp_arch_unknown;
 					continue;
 				}
@@ -674,7 +741,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
 			else if (strcmp(line, "[ppc]") == 0 ||
 				 strcmp(line, "[PPC]") == 0) {
 				if (native_arch != lxc_seccomp_arch_ppc &&
-						native_arch != lxc_seccomp_arch_ppc64) {
+				    native_arch != lxc_seccomp_arch_ppc64) {
 					cur_rule_arch = lxc_seccomp_arch_unknown;
 					continue;
 				}
@@ -699,7 +766,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
 			} else if (strcmp(line, "[mips]") == 0 ||
 				   strcmp(line, "[MIPS]") == 0) {
 				if (native_arch != lxc_seccomp_arch_mips &&
-						native_arch != lxc_seccomp_arch_mips64) {
+				    native_arch != lxc_seccomp_arch_mips64) {
 					cur_rule_arch = lxc_seccomp_arch_unknown;
 					continue;
 				}
@@ -721,7 +788,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
 			} else if (strcmp(line, "[mipsel]") == 0 ||
 				   strcmp(line, "[MIPSEL]") == 0) {
 				if (native_arch != lxc_seccomp_arch_mipsel &&
-						native_arch != lxc_seccomp_arch_mipsel64) {
+				    native_arch != lxc_seccomp_arch_mipsel64) {
 					cur_rule_arch = lxc_seccomp_arch_unknown;
 					continue;
 				}
@@ -756,57 +823,84 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
 			goto bad_rule;
 		}
 
-		if (cur_rule_arch == native_arch ||
-		    cur_rule_arch == lxc_seccomp_arch_native ||
-		    compat_arch[0] == SCMP_ARCH_NATIVE) {
-			INFO("Adding native rule for %s action %d(%s)", line, rule.action,
-			     get_action_name(rule.action));
-			if (!do_resolve_add_rule(SCMP_ARCH_NATIVE, line, conf->seccomp_ctx, &rule))
-				goto bad_rule;
-		}
-		else if (cur_rule_arch != lxc_seccomp_arch_all) {
-			int arch_index =
-				cur_rule_arch == lxc_seccomp_arch_mips64n32 ||
-				cur_rule_arch == lxc_seccomp_arch_mipsel64n32 ? 1 : 0;
+		if (!do_resolve_add_rule(SCMP_ARCH_NATIVE, line,
+					 conf->seccomp_ctx, &rule))
+			goto bad_rule;
+		INFO("Added native rule for arch %d for %s action %d(%s)",
+		     SCMP_ARCH_NATIVE, line, rule.action,
+		     get_action_name(rule.action));
 
-			INFO("Adding compat-only rule for %s action %d(%s)", line, rule.action,
-			     get_action_name(rule.action));
-			if (!do_resolve_add_rule(compat_arch[arch_index], line, compat_ctx[arch_index], &rule))
+		if (ctx.architectures[0] != SCMP_ARCH_NATIVE) {
+			if (!do_resolve_add_rule(ctx.architectures[0], line,
+						 ctx.contexts[0], &rule))
 				goto bad_rule;
+			INFO("Added compat rule for arch %d for %s action %d(%s)",
+			     ctx.architectures[0], line, rule.action,
+			     get_action_name(rule.action));
 		}
-		else {
-			INFO("Adding native rule for %s action %d(%s)", line, rule.action,
+
+		if (ctx.architectures[1] != SCMP_ARCH_NATIVE) {
+			if (!do_resolve_add_rule(ctx.architectures[1], line,
+						 ctx.contexts[1], &rule))
+				goto bad_rule;
+			INFO("Added compat rule for arch %d for %s action %d(%s)",
+			     ctx.architectures[1], line, rule.action,
 			     get_action_name(rule.action));
-			if (!do_resolve_add_rule(SCMP_ARCH_NATIVE, line, conf->seccomp_ctx, &rule))
+		}
+
+		if (ctx.architectures[2] != SCMP_ARCH_NATIVE) {
+			if (!do_resolve_add_rule(ctx.architectures[2], line,
+						ctx.contexts[2], &rule))
 				goto bad_rule;
-			INFO("Adding compat rule for %s action %d(%s)", line, rule.action,
+			INFO("Added native rule for arch %d for %s action %d(%s)",
+			     ctx.architectures[2], line, rule.action,
 			     get_action_name(rule.action));
-			if (!do_resolve_add_rule(compat_arch[0], line, compat_ctx[0], &rule))
-				goto bad_rule;
-			if (compat_arch[1] != SCMP_ARCH_NATIVE &&
-				!do_resolve_add_rule(compat_arch[1], line, compat_ctx[1], &rule))
-				goto bad_rule;
 		}
 	}
 
-	if (compat_ctx[0]) {
-		INFO("Merging compat seccomp contexts into main context");
-		if (compat_arch[0] != native_arch && compat_arch[0] != seccomp_arch_native()) {
-			ret = seccomp_merge(conf->seccomp_ctx, compat_ctx[0]);
+	INFO("Merging compat seccomp contexts into main context");
+	if (ctx.contexts[0]) {
+		if (ctx.needs_merge[0]) {
+			ret = seccomp_merge(conf->seccomp_ctx, ctx.contexts[0]);
 			if (ret < 0) {
-				ERROR("Failed to merge first compat seccomp context into main context");
+				ERROR("Failed to merge first compat seccomp "
+				      "context into main context");
 				goto bad;
 			}
 			TRACE("Merged first compat seccomp context into main context");
+		} else {
+			seccomp_release(ctx.contexts[0]);
+			ctx.contexts[0] = NULL;
 		}
+	}
 
-		if (compat_arch[1] && compat_arch[1] != native_arch && compat_arch[1] != seccomp_arch_native()) {
-			ret = seccomp_merge(conf->seccomp_ctx, compat_ctx[1]);
+	if (ctx.contexts[1]) {
+		if (ctx.needs_merge[1]) {
+			ret = seccomp_merge(conf->seccomp_ctx, ctx.contexts[1]);
 			if (ret < 0) {
-				ERROR("Failed to merge first compat seccomp context into main context");
+				ERROR("Failed to merge first compat seccomp "
+				      "context into main context");
 				goto bad;
 			}
 			TRACE("Merged second compat seccomp context into main context");
+		} else {
+			seccomp_release(ctx.contexts[1]);
+			ctx.contexts[1] = NULL;
+		}
+	}
+
+	if (ctx.contexts[2]) {
+		if (ctx.needs_merge[2]) {
+			ret = seccomp_merge(conf->seccomp_ctx, ctx.contexts[2]);
+			if (ret < 0) {
+				ERROR("Failed to merge third compat seccomp "
+				      "context into main context");
+				goto bad;
+			}
+			TRACE("Merged third compat seccomp context into main context");
+		} else {
+			seccomp_release(ctx.contexts[2]);
+			ctx.contexts[2] = NULL;
 		}
 	}
 
@@ -816,10 +910,13 @@ bad_arch:
 	ERROR("Unsupported arch: %s.", line);
 bad_rule:
 bad:
-	if (compat_ctx[0])
-		seccomp_release(compat_ctx[0]);
-	if (compat_ctx[1])
-		seccomp_release(compat_ctx[1]);
+	if (ctx.contexts[0])
+		seccomp_release(ctx.contexts[0]);
+	if (ctx.contexts[1])
+		seccomp_release(ctx.contexts[1]);
+	if (ctx.contexts[2])
+		seccomp_release(ctx.contexts[2]);
+
 	return -1;
 }
 #else /* HAVE_DECL_SECCOMP_SYSCALL_RESOLVE_NAME_ARCH */

src/lxc/tools/lxc_execute.c

@@ -104,6 +104,7 @@ and execs COMMAND into this container.\n\
 \n\
 Options :\n\
   -n, --name=NAME      NAME of the container\n\
+  -d, --daemon         Daemonize the container\n\
   -f, --rcfile=FILE    Load configuration file FILE\n\
   -s, --define KEY=VAL Assign VAL to configuration variable KEY\n\
   -u, --uid=UID        Execute COMMAND with UID inside the container\n\

src/tests/api_reboot.c

@@ -59,7 +59,6 @@ int main(int argc, char *argv[])
 		lxc_error("%s\n", "Container \"reboot\" is not defined");
 		goto on_error_put;
 	}
-
 	c->clear_config(c);
 
 	if (!c->load_config(c, NULL)) {