execve fixes for v6.9-rc2

- Fix selftests to conform to the TAP output format (Muhammad Usama Anjum)
 
 - Fix NOMMU linux_binprm::exec pointer in auxv (Max Filippov)
 
 - Replace deprecated strncpy usage (Justin Stitt)
 
 - Replace another /bin/sh instance in selftests
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Merge tag 'execve-v6.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull execve fixes from Kees Cook:

 - Fix selftests to conform to the TAP output format (Muhammad Usama
   Anjum)

 - Fix NOMMU linux_binprm::exec pointer in auxv (Max Filippov)

 - Replace deprecated strncpy usage (Justin Stitt)

 - Replace another /bin/sh instance in selftests

* tag 'execve-v6.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  binfmt: replace deprecated strncpy
  exec: Fix NOMMU linux_binprm::exec in transfer_args_to_stack()
  selftests/exec: Convert remaining /bin/sh to /bin/bash
  selftests/exec: execveat: Improve debug reporting
  selftests/exec: recursion-depth: conform test to TAP format output
  selftests/exec: load_address: conform test to TAP format output
  selftests/exec: binfmt_script: Add the overall result line according to TAP

fs/binfmt_elf_fdpic.c

@@ -1359,7 +1359,7 @@ static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
 	SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
 	SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
 	rcu_read_unlock();
-	strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
+	get_task_comm(psinfo->pr_fname, p);
 
 	return 0;
 }

fs/exec.c

@@ -895,6 +895,7 @@ int transfer_args_to_stack(struct linux_binprm *bprm,
 			goto out;
 	}
 
+	bprm->exec += *sp_location - MAX_ARG_PAGES * PAGE_SIZE;
 	*sp_location = sp;
 
 out:

tools/testing/selftests/exec/Makefile

@@ -19,8 +19,8 @@ include ../lib.mk
 
 $(OUTPUT)/subdir:
 	mkdir -p $@
-$(OUTPUT)/script:
-	echo '#!/bin/sh' > $@
+$(OUTPUT)/script: Makefile
+	echo '#!/bin/bash' > $@
 	echo 'exit $$*' >> $@
 	chmod +x $@
 $(OUTPUT)/execveat.symlink: $(OUTPUT)/execveat

tools/testing/selftests/exec/binfmt_script.py

@@ -16,6 +16,8 @@ SIZE=256
 NAME_MAX=int(subprocess.check_output(["getconf", "NAME_MAX", "."]))
 
 test_num=0
+pass_num=0
+fail_num=0
 
 code='''#!/usr/bin/perl
 print "Executed interpreter! Args:\n";
@@ -42,7 +44,7 @@ foreach my $a (@ARGV) {
 # ...
 def test(name, size, good=True, leading="", root="./", target="/perl",
                      fill="A", arg="", newline="\n", hashbang="#!"):
-    global test_num, tests, NAME_MAX
+    global test_num, pass_num, fail_num, tests, NAME_MAX
     test_num += 1
     if test_num > tests:
         raise ValueError("more binfmt_script tests than expected! (want %d, expected %d)"
@@ -80,16 +82,20 @@ def test(name, size, good=True, leading="", root="./", target="/perl",
         if good:
             print("ok %d - binfmt_script %s (successful good exec)"
                   % (test_num, name))
+            pass_num += 1
         else:
             print("not ok %d - binfmt_script %s succeeded when it should have failed"
                   % (test_num, name))
+            fail_num = 1
     else:
         if good:
             print("not ok %d - binfmt_script %s failed when it should have succeeded (rc:%d)"
                   % (test_num, name, proc.returncode))
+            fail_num = 1
         else:
             print("ok %d - binfmt_script %s (correctly failed bad exec)"
                   % (test_num, name))
+            pass_num += 1
 
     # Clean up crazy binaries
     os.unlink(script)
@@ -166,6 +172,8 @@ test(name="two-under-trunc-arg", size=int(SIZE/2), arg=" ")
 test(name="two-under-leading",   size=int(SIZE/2), leading=" ")
 test(name="two-under-lead-trunc-arg", size=int(SIZE/2), leading=" ", arg=" ")
 
+print("# Totals: pass:%d fail:%d xfail:0 xpass:0 skip:0 error:0" % (pass_num, fail_num))
+
 if test_num != tests:
     raise ValueError("fewer binfmt_script tests than expected! (ran %d, expected %d"
                      % (test_num, tests))

tools/testing/selftests/exec/execveat.c

@@ -98,10 +98,9 @@ static int check_execveat_invoked_rc(int fd, const char *path, int flags,
 	if (child == 0) {
 		/* Child: do execveat(). */
 		rc = execveat_(fd, path, argv, envp, flags);
-		ksft_print_msg("execveat() failed, rc=%d errno=%d (%s)\n",
+		ksft_print_msg("child execveat() failed, rc=%d errno=%d (%s)\n",
 			       rc, errno, strerror(errno));
-		ksft_test_result_fail("%s\n", test_name);
-		exit(1);  /* should not reach here */
+		exit(errno);
 	}
 	/* Parent: wait for & check child's exit status. */
 	rc = waitpid(child, &status, 0);
@@ -226,11 +225,14 @@ static int check_execveat_pathmax(int root_dfd, const char *src, int is_script)
 	 * "If the command name is found, but it is not an executable utility,
 	 * the exit status shall be 126."), so allow either.
 	 */
-	if (is_script)
+	if (is_script) {
+		ksft_print_msg("Invoke script via root_dfd and relative filename\n");
 		fail += check_execveat_invoked_rc(root_dfd, longpath + 1, 0,
 						  127, 126);
-	else
+	} else {
+		ksft_print_msg("Invoke exec via root_dfd and relative filename\n");
 		fail += check_execveat(root_dfd, longpath + 1, 0);
+	}
 
 	return fail;
 }

tools/testing/selftests/exec/load_address.c

@@ -5,6 +5,7 @@
 #include <link.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include "../kselftest.h"
 
 struct Statistics {
 	unsigned long long load_address;
@@ -41,28 +42,23 @@ int main(int argc, char **argv)
 	unsigned long long misalign;
 	int ret;
 
+	ksft_print_header();
+	ksft_set_plan(1);
+
 	ret = dl_iterate_phdr(ExtractStatistics, &extracted);
-	if (ret != 1) {
-		fprintf(stderr, "FAILED\n");
-		return 1;
-	}
+	if (ret != 1)
+		ksft_exit_fail_msg("FAILED: dl_iterate_phdr\n");
 
-	if (extracted.alignment == 0) {
-		fprintf(stderr, "No alignment found\n");
-		return 1;
-	} else if (extracted.alignment & (extracted.alignment - 1)) {
-		fprintf(stderr, "Alignment is not a power of 2\n");
-		return 1;
-	}
+	if (extracted.alignment == 0)
+		ksft_exit_fail_msg("FAILED: No alignment found\n");
+	else if (extracted.alignment & (extracted.alignment - 1))
+		ksft_exit_fail_msg("FAILED: Alignment is not a power of 2\n");
 
 	misalign = extracted.load_address & (extracted.alignment - 1);
-	if (misalign) {
-		printf("alignment = %llu, load_address = %llu\n",
-			extracted.alignment, extracted.load_address);
-		fprintf(stderr, "FAILED\n");
-		return 1;
-	}
+	if (misalign)
+		ksft_exit_fail_msg("FAILED: alignment = %llu, load_address = %llu\n",
+				   extracted.alignment, extracted.load_address);
 
-	fprintf(stderr, "PASS\n");
-	return 0;
+	ksft_test_result_pass("Completed\n");
+	ksft_finished();
 }

tools/testing/selftests/exec/recursion-depth.c

@@ -23,45 +23,44 @@
 #include <fcntl.h>
 #include <sys/mount.h>
 #include <unistd.h>
+#include "../kselftest.h"
 
 int main(void)
 {
+	int fd, rv;
+
+	ksft_print_header();
+	ksft_set_plan(1);
+
 	if (unshare(CLONE_NEWNS) == -1) {
 		if (errno == ENOSYS || errno == EPERM) {
-			fprintf(stderr, "error: unshare, errno %d\n", errno);
-			return 4;
+			ksft_test_result_skip("error: unshare, errno %d\n", errno);
+			ksft_finished();
 		}
-		fprintf(stderr, "error: unshare, errno %d\n", errno);
-		return 1;
-	}
-	if (mount(NULL, "/", NULL, MS_PRIVATE|MS_REC, NULL) == -1) {
-		fprintf(stderr, "error: mount '/', errno %d\n", errno);
-		return 1;
+		ksft_exit_fail_msg("error: unshare, errno %d\n", errno);
 	}
+
+	if (mount(NULL, "/", NULL, MS_PRIVATE | MS_REC, NULL) == -1)
+		ksft_exit_fail_msg("error: mount '/', errno %d\n", errno);
+
 	/* Require "exec" filesystem. */
-	if (mount(NULL, "/tmp", "ramfs", 0, NULL) == -1) {
-		fprintf(stderr, "error: mount ramfs, errno %d\n", errno);
-		return 1;
-	}
+	if (mount(NULL, "/tmp", "ramfs", 0, NULL) == -1)
+		ksft_exit_fail_msg("error: mount ramfs, errno %d\n", errno);
 
 #define FILENAME "/tmp/1"
 
-	int fd = creat(FILENAME, 0700);
-	if (fd == -1) {
-		fprintf(stderr, "error: creat, errno %d\n", errno);
-		return 1;
-	}
+	fd = creat(FILENAME, 0700);
+	if (fd == -1)
+		ksft_exit_fail_msg("error: creat, errno %d\n", errno);
+
 #define S "#!" FILENAME "\n"
-	if (write(fd, S, strlen(S)) != strlen(S)) {
-		fprintf(stderr, "error: write, errno %d\n", errno);
-		return 1;
-	}
+	if (write(fd, S, strlen(S)) != strlen(S))
+		ksft_exit_fail_msg("error: write, errno %d\n", errno);
+
 	close(fd);
 
-	int rv = execve(FILENAME, NULL, NULL);
-	if (rv == -1 && errno == ELOOP) {
-		return 0;
-	}
-	fprintf(stderr, "error: execve, rv %d, errno %d\n", rv, errno);
-	return 1;
+	rv = execve(FILENAME, NULL, NULL);
+	ksft_test_result(rv == -1 && errno == ELOOP,
+			 "execve failed as expected (ret %d, errno %d)\n", rv, errno);
+	ksft_finished();
 }