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* [PATCH v2] tests/secretmem: add test
@ 2022-08-31 15:34 Christian Göttsche
  2022-09-12 13:41 ` Ondrej Mosnacek
  0 siblings, 1 reply; 4+ messages in thread
From: Christian Göttsche @ 2022-08-31 15:34 UTC (permalink / raw)
  To: selinux

Add test for memfd_secret(2) anonymous inodes check added in 6.0 via
2bfe15c52612 ("mm: create security context for memfd_secret inodes").

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
---
v2:
   - print mmap failures to stdout, since they are expected when
     mapping with PROT_EXEC
---
 .github/workflows/checks.yml |  4 ++
 Vagrantfile                  | 10 +++--
 policy/Makefile              |  4 ++
 policy/test_secretmem.te     | 33 ++++++++++++++
 tests/Makefile               |  5 +++
 tests/secretmem/.gitignore   |  1 +
 tests/secretmem/Makefile     |  5 +++
 tests/secretmem/secretmem.c  | 83 ++++++++++++++++++++++++++++++++++++
 tests/secretmem/test         | 39 +++++++++++++++++
 9 files changed, 180 insertions(+), 4 deletions(-)
 create mode 100644 policy/test_secretmem.te
 create mode 100644 tests/secretmem/.gitignore
 create mode 100644 tests/secretmem/Makefile
 create mode 100644 tests/secretmem/secretmem.c
 create mode 100755 tests/secretmem/test

diff --git a/.github/workflows/checks.yml b/.github/workflows/checks.yml
index 714bb49..ae81925 100644
--- a/.github/workflows/checks.yml
+++ b/.github/workflows/checks.yml
@@ -38,6 +38,10 @@ jobs:
         run: vagrant up
       - name: Wait for the machine to come up if rebooting
         run: while ! vagrant ssh -- true; do sleep 1; done
+      - name: Show Vagrant VM details
+        run: |
+          vagrant ssh -- uname -a
+          vagrant ssh -- cat /proc/cmdline
       - name: Run SELinux testsuite
         run: vagrant ssh -- sudo make -C /root/testsuite test
       - name: Check unwanted denials
diff --git a/Vagrantfile b/Vagrantfile
index f73586c..6f7675f 100644
--- a/Vagrantfile
+++ b/Vagrantfile
@@ -37,15 +37,12 @@ Vagrant.configure("2") do |config|
   when 'default'
     dnf_opts = ''
     kernel_pkgs = 'kernel-devel-"$(uname -r)" kernel-modules-"$(uname -r)"'
-    reboot_cmd = ''
   when 'latest'
     dnf_opts = ''
     kernel_pkgs = 'kernel-devel kernel-modules'
-    reboot_cmd = 'reboot'
   when 'secnext'
     dnf_opts = '--nogpgcheck --releasever rawhide --repofrompath kernel-secnext,https://repo.paul-moore.com/rawhide/x86_64'
     kernel_pkgs = 'kernel-devel kernel-modules'
-    reboot_cmd = 'reboot'
   else
     print("Invalid KERNEL_TYPE '#{ENV['KERNEL_TYPE']}'")
     abort
@@ -93,7 +90,12 @@ EOF
       jfsutils \
       dosfstools \
       #{kernel_pkgs}
+
     #{extra_commands}
-    #{reboot_cmd}
+
+    # for secretmem test
+    grubby --update-kernel=ALL --args=secretmem.enable=1
+
+    reboot
 SCRIPT
 end
diff --git a/policy/Makefile b/policy/Makefile
index b6f2f32..403802b 100644
--- a/policy/Makefile
+++ b/policy/Makefile
@@ -162,6 +162,10 @@ ifeq (x$(DISTRO),$(filter x$(DISTRO),xRHEL4 xRHEL5 xRHEL6))
 TARGETS:=$(filter-out test_overlayfs.te test_mqueue.te test_ibpkey.te, $(TARGETS))
 endif
 
+ifeq ($(shell grep -q anon_inode $(POLDEV)/include/support/all_perms.spt && echo true),true)
+TARGETS += test_secretmem.te
+endif
+
 all: build
 
 expand_check:
diff --git a/policy/test_secretmem.te b/policy/test_secretmem.te
new file mode 100644
index 0000000..357f41d
--- /dev/null
+++ b/policy/test_secretmem.te
@@ -0,0 +1,33 @@
+#################################
+#
+# Policy for testing secretmem operations
+#
+
+# Private type for secret memory
+type test_secretmem_inode_t;
+
+# Domain not allowed to create secret memory
+type test_nocreate_secretmem_t;
+testsuite_domain_type_minimal(test_nocreate_secretmem_t)
+
+# Domain allowed to create secret memory with the own domain type
+type test_create_secretmem_t;
+testsuite_domain_type_minimal(test_create_secretmem_t)
+allow test_create_secretmem_t self:anon_inode create;
+
+# Domain allowed to create secret memory with the own domain type and allowed to map WX
+type test_create_wx_secretmem_t;
+testsuite_domain_type_minimal(test_create_wx_secretmem_t)
+allow test_create_wx_secretmem_t self:anon_inode create;
+allow test_create_wx_secretmem_t self:process execmem;
+
+# Domain not allowed to create secret memory via a type transition to a private type
+type test_nocreate_transition_secretmem_t;
+testsuite_domain_type_minimal(test_nocreate_transition_secretmem_t)
+type_transition test_nocreate_transition_secretmem_t test_nocreate_transition_secretmem_t:anon_inode test_secretmem_inode_t "[secretmem]";
+
+# Domain allowed to create secret memory via a type transition to a private type
+type test_create_transition_secretmem_t;
+testsuite_domain_type_minimal(test_create_transition_secretmem_t)
+type_transition test_create_transition_secretmem_t test_create_transition_secretmem_t:anon_inode test_secretmem_inode_t "[secretmem]";
+allow test_create_transition_secretmem_t test_secretmem_inode_t:anon_inode create;
diff --git a/tests/Makefile b/tests/Makefile
index 8abd438..b50cbc6 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -145,6 +145,11 @@ SUBDIRS += vsock_socket
 endif
 endif
 
+# memfd_secret(2) is available since 5.14, but only confined since 6.0
+ifneq ($(shell ./kvercmp $$(uname -r) 6.0),-1)
+SUBDIRS += secretmem
+endif
+
 ifeq ($(DISTRO),RHEL4)
     SUBDIRS:=$(filter-out bounds dyntrace dyntrans inet_socket mmap nnp_nosuid overlay unix_socket, $(SUBDIRS))
 endif
diff --git a/tests/secretmem/.gitignore b/tests/secretmem/.gitignore
new file mode 100644
index 0000000..17e1c19
--- /dev/null
+++ b/tests/secretmem/.gitignore
@@ -0,0 +1 @@
+secretmem
diff --git a/tests/secretmem/Makefile b/tests/secretmem/Makefile
new file mode 100644
index 0000000..c27d5f0
--- /dev/null
+++ b/tests/secretmem/Makefile
@@ -0,0 +1,5 @@
+TARGETS=secretmem
+
+all: $(TARGETS)
+clean:
+	rm -f $(TARGETS)
diff --git a/tests/secretmem/secretmem.c b/tests/secretmem/secretmem.c
new file mode 100644
index 0000000..0d541ee
--- /dev/null
+++ b/tests/secretmem/secretmem.c
@@ -0,0 +1,83 @@
+#include <errno.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <sys/mman.h>
+#include <sys/syscall.h>
+
+#ifndef __NR_memfd_secret
+# define __NR_memfd_secret 447
+#endif
+
+#define TEXT "Hello World!\nHello World!\nHello World!\nHello World!\nHello World!\nHello World!\n"
+
+static int _memfd_secret(unsigned long flags)
+{
+	return syscall(__NR_memfd_secret, flags);
+}
+
+int main(int argc, const char *argv[])
+{
+	long page_size;
+	int fd, flags;
+	char *mem;
+	bool check = (argc == 2 && strcmp(argv[1], "check") == 0);
+	bool wx = (argc == 2 && strcmp(argv[1], "wx") == 0);
+
+	page_size = sysconf(_SC_PAGESIZE);
+	if (page_size <= 0) {
+		fprintf(stderr, "failed to get pagesize, got %ld:  %s\n", page_size,
+			strerror(errno));
+		return EXIT_FAILURE;
+	}
+
+	fd = _memfd_secret(0);
+	if (fd < 0) {
+		printf("memfd_secret() failed:  %s\n", strerror(errno));
+		if (check && errno != ENOSYS)
+			return EXIT_SUCCESS;
+
+		return EXIT_FAILURE;
+	}
+
+	if (check)
+		return EXIT_SUCCESS;
+
+	if (ftruncate(fd, page_size) < 0) {
+		fprintf(stderr, "ftruncate failed:  %s\n", strerror(errno));
+	}
+
+	flags = PROT_READ | PROT_WRITE;
+	if (wx)
+		flags |= PROT_EXEC;
+
+	mem = mmap(NULL, page_size, flags, MAP_SHARED, fd, 0);
+	if (mem == MAP_FAILED || !mem) {
+		printf("unable to mmap secret memory:  %s\n", strerror(errno));
+		close(fd);
+		return EXIT_FAILURE;
+	}
+
+	close(fd);
+
+	memcpy(mem, TEXT, sizeof TEXT);
+
+	if (memcmp(mem, TEXT, sizeof TEXT) != 0) {
+		fprintf(stderr, "data not synced (1)\n");
+		munmap(mem, page_size);
+		return EXIT_FAILURE;
+	}
+
+	if (strlen(mem) + 1 != sizeof TEXT) {
+		fprintf(stderr, "data not synced (2)\n");
+		munmap(mem, page_size);
+		return EXIT_FAILURE;
+	}
+
+	munmap(mem, page_size);
+
+	return EXIT_SUCCESS;
+}
diff --git a/tests/secretmem/test b/tests/secretmem/test
new file mode 100755
index 0000000..d17d423
--- /dev/null
+++ b/tests/secretmem/test
@@ -0,0 +1,39 @@
+#!/usr/bin/perl
+
+use Test::More;
+
+BEGIN {
+    $basedir = $0;
+    $basedir =~ s|(.*)/[^/]*|$1|;
+
+    $result =
+      system "runcon -t test_nocreate_secretmem_t $basedir/secretmem check";
+    if ( $result ne 0 ) {
+        plan skip_all => "memfd_secret(2) not available";
+    }
+    else {
+        plan tests => 6;
+    }
+}
+
+$result = system "runcon -t test_nocreate_secretmem_t $basedir/secretmem";
+ok( $result >> 8 eq 1 );
+
+$result = system "runcon -t test_create_secretmem_t $basedir/secretmem";
+ok( $result eq 0 );
+
+$result = system "runcon -t test_create_secretmem_t $basedir/secretmem wx";
+ok( $result >> 8 eq 1 );
+
+$result = system "runcon -t test_create_wx_secretmem_t $basedir/secretmem wx";
+ok( $result >> 8 eq 1 );
+
+$result =
+  system "runcon -t test_nocreate_transition_secretmem_t $basedir/secretmem";
+ok( $result >> 8 eq 1 );
+
+$result =
+  system "runcon -t test_create_transition_secretmem_t $basedir/secretmem";
+ok( $result eq 0 );
+
+exit;
-- 
2.37.2


^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH v2] tests/secretmem: add test
  2022-08-31 15:34 [PATCH v2] tests/secretmem: add test Christian Göttsche
@ 2022-09-12 13:41 ` Ondrej Mosnacek
  2022-10-11 14:02   ` Ondrej Mosnacek
  0 siblings, 1 reply; 4+ messages in thread
From: Ondrej Mosnacek @ 2022-09-12 13:41 UTC (permalink / raw)
  To: Christian Göttsche; +Cc: SElinux list

On Wed, Aug 31, 2022 at 5:34 PM Christian Göttsche
<cgzones@googlemail.com> wrote:
> Add test for memfd_secret(2) anonymous inodes check added in 6.0 via
> 2bfe15c52612 ("mm: create security context for memfd_secret inodes").
>
> Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
> ---
> v2:
>    - print mmap failures to stdout, since they are expected when
>      mapping with PROT_EXEC
> ---
>  .github/workflows/checks.yml |  4 ++
>  Vagrantfile                  | 10 +++--
>  policy/Makefile              |  4 ++
>  policy/test_secretmem.te     | 33 ++++++++++++++
>  tests/Makefile               |  5 +++
>  tests/secretmem/.gitignore   |  1 +
>  tests/secretmem/Makefile     |  5 +++
>  tests/secretmem/secretmem.c  | 83 ++++++++++++++++++++++++++++++++++++
>  tests/secretmem/test         | 39 +++++++++++++++++
>  9 files changed, 180 insertions(+), 4 deletions(-)
>  create mode 100644 policy/test_secretmem.te
>  create mode 100644 tests/secretmem/.gitignore
>  create mode 100644 tests/secretmem/Makefile
>  create mode 100644 tests/secretmem/secretmem.c
>  create mode 100755 tests/secretmem/test

This looks good to me, with some minor comments below.

> diff --git a/tests/secretmem/secretmem.c b/tests/secretmem/secretmem.c
> new file mode 100644
> index 0000000..0d541ee
> --- /dev/null
> +++ b/tests/secretmem/secretmem.c
> @@ -0,0 +1,83 @@
> +#include <errno.h>
> +#include <stdbool.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <unistd.h>
> +
> +#include <sys/mman.h>
> +#include <sys/syscall.h>
> +
> +#ifndef __NR_memfd_secret
> +# define __NR_memfd_secret 447
> +#endif
> +
> +#define TEXT "Hello World!\nHello World!\nHello World!\nHello World!\nHello World!\nHello World!\n"
> +
> +static int _memfd_secret(unsigned long flags)
> +{
> +       return syscall(__NR_memfd_secret, flags);
> +}
> +
> +int main(int argc, const char *argv[])
> +{
> +       long page_size;
> +       int fd, flags;
> +       char *mem;
> +       bool check = (argc == 2 && strcmp(argv[1], "check") == 0);
> +       bool wx = (argc == 2 && strcmp(argv[1], "wx") == 0);
> +
> +       page_size = sysconf(_SC_PAGESIZE);
> +       if (page_size <= 0) {
> +               fprintf(stderr, "failed to get pagesize, got %ld:  %s\n", page_size,
> +                       strerror(errno));
> +               return EXIT_FAILURE;
> +       }
> +
> +       fd = _memfd_secret(0);
> +       if (fd < 0) {
> +               printf("memfd_secret() failed:  %s\n", strerror(errno));
> +               if (check && errno != ENOSYS)
> +                       return EXIT_SUCCESS;
> +
> +               return EXIT_FAILURE;
> +       }
> +
> +       if (check)
> +               return EXIT_SUCCESS;
> +
> +       if (ftruncate(fd, page_size) < 0) {
> +               fprintf(stderr, "ftruncate failed:  %s\n", strerror(errno));
> +       }
> +
> +       flags = PROT_READ | PROT_WRITE;
> +       if (wx)
> +               flags |= PROT_EXEC;
> +
> +       mem = mmap(NULL, page_size, flags, MAP_SHARED, fd, 0);
> +       if (mem == MAP_FAILED || !mem) {
> +               printf("unable to mmap secret memory:  %s\n", strerror(errno));
> +               close(fd);
> +               return EXIT_FAILURE;
> +       }
> +
> +       close(fd);
> +
> +       memcpy(mem, TEXT, sizeof TEXT);

Please use parentheses with sizeof. When the argument is a type name
they are mandatory so it's better to use them always for consistency.
See also:
https://lore.kernel.org/lkml/CA+55aFwey-q4716pYYSi=3R_ucw84zFspDXMXmzvzc72XSc9Lg@mail.gmail.com/
https://lore.kernel.org/lkml/CA+55aFwcJgAFiow1sSo7mkF9n0MpTw80gjAszazyBrRcmbph-g@mail.gmail.com/

> +
> +       if (memcmp(mem, TEXT, sizeof TEXT) != 0) {
> +               fprintf(stderr, "data not synced (1)\n");
> +               munmap(mem, page_size);
> +               return EXIT_FAILURE;
> +       }
> +
> +       if (strlen(mem) + 1 != sizeof TEXT) {
> +               fprintf(stderr, "data not synced (2)\n");
> +               munmap(mem, page_size);
> +               return EXIT_FAILURE;
> +       }

What is the point of this second check? The previous check already
asserts that the contents are char-to-char equal to TEXT (including
the terminating null character), which implies string length
equivalence as well.

> +
> +       munmap(mem, page_size);
> +
> +       return EXIT_SUCCESS;
> +}

--
Ondrej Mosnacek
Senior Software Engineer, Linux Security - SELinux kernel
Red Hat, Inc.


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH v2] tests/secretmem: add test
  2022-09-12 13:41 ` Ondrej Mosnacek
@ 2022-10-11 14:02   ` Ondrej Mosnacek
  2022-10-11 16:10     ` Christian Göttsche
  0 siblings, 1 reply; 4+ messages in thread
From: Ondrej Mosnacek @ 2022-10-11 14:02 UTC (permalink / raw)
  To: Christian Göttsche; +Cc: SElinux list

On Mon, Sep 12, 2022 at 3:41 PM Ondrej Mosnacek <omosnace@redhat.com> wrote:
> On Wed, Aug 31, 2022 at 5:34 PM Christian Göttsche
> <cgzones@googlemail.com> wrote:
> > Add test for memfd_secret(2) anonymous inodes check added in 6.0 via
> > 2bfe15c52612 ("mm: create security context for memfd_secret inodes").
> >
> > Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
> > ---
> > v2:
> >    - print mmap failures to stdout, since they are expected when
> >      mapping with PROT_EXEC
> > ---
> >  .github/workflows/checks.yml |  4 ++
> >  Vagrantfile                  | 10 +++--
> >  policy/Makefile              |  4 ++
> >  policy/test_secretmem.te     | 33 ++++++++++++++
> >  tests/Makefile               |  5 +++
> >  tests/secretmem/.gitignore   |  1 +
> >  tests/secretmem/Makefile     |  5 +++
> >  tests/secretmem/secretmem.c  | 83 ++++++++++++++++++++++++++++++++++++
> >  tests/secretmem/test         | 39 +++++++++++++++++
> >  9 files changed, 180 insertions(+), 4 deletions(-)
> >  create mode 100644 policy/test_secretmem.te
> >  create mode 100644 tests/secretmem/.gitignore
> >  create mode 100644 tests/secretmem/Makefile
> >  create mode 100644 tests/secretmem/secretmem.c
> >  create mode 100755 tests/secretmem/test
>
> This looks good to me, with some minor comments below.
>
> > diff --git a/tests/secretmem/secretmem.c b/tests/secretmem/secretmem.c
> > new file mode 100644
> > index 0000000..0d541ee
> > --- /dev/null
> > +++ b/tests/secretmem/secretmem.c
> > @@ -0,0 +1,83 @@
> > +#include <errno.h>
> > +#include <stdbool.h>
> > +#include <stdio.h>
> > +#include <stdlib.h>
> > +#include <string.h>
> > +#include <unistd.h>
> > +
> > +#include <sys/mman.h>
> > +#include <sys/syscall.h>
> > +
> > +#ifndef __NR_memfd_secret
> > +# define __NR_memfd_secret 447
> > +#endif
> > +
> > +#define TEXT "Hello World!\nHello World!\nHello World!\nHello World!\nHello World!\nHello World!\n"
> > +
> > +static int _memfd_secret(unsigned long flags)
> > +{
> > +       return syscall(__NR_memfd_secret, flags);
> > +}
> > +
> > +int main(int argc, const char *argv[])
> > +{
> > +       long page_size;
> > +       int fd, flags;
> > +       char *mem;
> > +       bool check = (argc == 2 && strcmp(argv[1], "check") == 0);
> > +       bool wx = (argc == 2 && strcmp(argv[1], "wx") == 0);
> > +
> > +       page_size = sysconf(_SC_PAGESIZE);
> > +       if (page_size <= 0) {
> > +               fprintf(stderr, "failed to get pagesize, got %ld:  %s\n", page_size,
> > +                       strerror(errno));
> > +               return EXIT_FAILURE;
> > +       }
> > +
> > +       fd = _memfd_secret(0);
> > +       if (fd < 0) {
> > +               printf("memfd_secret() failed:  %s\n", strerror(errno));
> > +               if (check && errno != ENOSYS)
> > +                       return EXIT_SUCCESS;
> > +
> > +               return EXIT_FAILURE;
> > +       }
> > +
> > +       if (check)
> > +               return EXIT_SUCCESS;
> > +
> > +       if (ftruncate(fd, page_size) < 0) {
> > +               fprintf(stderr, "ftruncate failed:  %s\n", strerror(errno));
> > +       }
> > +
> > +       flags = PROT_READ | PROT_WRITE;
> > +       if (wx)
> > +               flags |= PROT_EXEC;
> > +
> > +       mem = mmap(NULL, page_size, flags, MAP_SHARED, fd, 0);
> > +       if (mem == MAP_FAILED || !mem) {
> > +               printf("unable to mmap secret memory:  %s\n", strerror(errno));
> > +               close(fd);
> > +               return EXIT_FAILURE;
> > +       }
> > +
> > +       close(fd);
> > +
> > +       memcpy(mem, TEXT, sizeof TEXT);
>
> Please use parentheses with sizeof. When the argument is a type name
> they are mandatory so it's better to use them always for consistency.
> See also:
> https://lore.kernel.org/lkml/CA+55aFwey-q4716pYYSi=3R_ucw84zFspDXMXmzvzc72XSc9Lg@mail.gmail.com/
> https://lore.kernel.org/lkml/CA+55aFwcJgAFiow1sSo7mkF9n0MpTw80gjAszazyBrRcmbph-g@mail.gmail.com/
>
> > +
> > +       if (memcmp(mem, TEXT, sizeof TEXT) != 0) {
> > +               fprintf(stderr, "data not synced (1)\n");
> > +               munmap(mem, page_size);
> > +               return EXIT_FAILURE;
> > +       }
> > +
> > +       if (strlen(mem) + 1 != sizeof TEXT) {
> > +               fprintf(stderr, "data not synced (2)\n");
> > +               munmap(mem, page_size);
> > +               return EXIT_FAILURE;
> > +       }
>
> What is the point of this second check? The previous check already
> asserts that the contents are char-to-char equal to TEXT (including
> the terminating null character), which implies string length
> equivalence as well.
>
> > +
> > +       munmap(mem, page_size);
> > +
> > +       return EXIT_SUCCESS;
> > +}

You only pushed the updated version to the GitHub PR
(https://github.com/SELinuxProject/selinux-testsuite/pull/80), but
anyway I took that version and applied it (just removed the changelog
from the commit message and added my SOB):
https://github.com/SELinuxProject/selinux-testsuite/commit/77352e748f006c343d602e4be03ae0d2cfcca831


--
Ondrej Mosnacek
Senior Software Engineer, Linux Security - SELinux kernel
Red Hat, Inc.


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH v2] tests/secretmem: add test
  2022-10-11 14:02   ` Ondrej Mosnacek
@ 2022-10-11 16:10     ` Christian Göttsche
  0 siblings, 0 replies; 4+ messages in thread
From: Christian Göttsche @ 2022-10-11 16:10 UTC (permalink / raw)
  To: Ondrej Mosnacek; +Cc: SElinux list

On Tue, 11 Oct 2022 at 16:02, Ondrej Mosnacek <omosnace@redhat.com> wrote:
>
> On Mon, Sep 12, 2022 at 3:41 PM Ondrej Mosnacek <omosnace@redhat.com> wrote:
> > On Wed, Aug 31, 2022 at 5:34 PM Christian Göttsche
> > <cgzones@googlemail.com> wrote:
> > > Add test for memfd_secret(2) anonymous inodes check added in 6.0 via
> > > 2bfe15c52612 ("mm: create security context for memfd_secret inodes").
> > >
> > > Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
> > > ---
> > > v2:
> > >    - print mmap failures to stdout, since they are expected when
> > >      mapping with PROT_EXEC
> > > ---
> > >  .github/workflows/checks.yml |  4 ++
> > >  Vagrantfile                  | 10 +++--
> > >  policy/Makefile              |  4 ++
> > >  policy/test_secretmem.te     | 33 ++++++++++++++
> > >  tests/Makefile               |  5 +++
> > >  tests/secretmem/.gitignore   |  1 +
> > >  tests/secretmem/Makefile     |  5 +++
> > >  tests/secretmem/secretmem.c  | 83 ++++++++++++++++++++++++++++++++++++
> > >  tests/secretmem/test         | 39 +++++++++++++++++
> > >  9 files changed, 180 insertions(+), 4 deletions(-)
> > >  create mode 100644 policy/test_secretmem.te
> > >  create mode 100644 tests/secretmem/.gitignore
> > >  create mode 100644 tests/secretmem/Makefile
> > >  create mode 100644 tests/secretmem/secretmem.c
> > >  create mode 100755 tests/secretmem/test
> >
> > This looks good to me, with some minor comments below.
> >
> > > diff --git a/tests/secretmem/secretmem.c b/tests/secretmem/secretmem.c
> > > new file mode 100644
> > > index 0000000..0d541ee
> > > --- /dev/null
> > > +++ b/tests/secretmem/secretmem.c
> > > @@ -0,0 +1,83 @@
> > > +#include <errno.h>
> > > +#include <stdbool.h>
> > > +#include <stdio.h>
> > > +#include <stdlib.h>
> > > +#include <string.h>
> > > +#include <unistd.h>
> > > +
> > > +#include <sys/mman.h>
> > > +#include <sys/syscall.h>
> > > +
> > > +#ifndef __NR_memfd_secret
> > > +# define __NR_memfd_secret 447
> > > +#endif
> > > +
> > > +#define TEXT "Hello World!\nHello World!\nHello World!\nHello World!\nHello World!\nHello World!\n"
> > > +
> > > +static int _memfd_secret(unsigned long flags)
> > > +{
> > > +       return syscall(__NR_memfd_secret, flags);
> > > +}
> > > +
> > > +int main(int argc, const char *argv[])
> > > +{
> > > +       long page_size;
> > > +       int fd, flags;
> > > +       char *mem;
> > > +       bool check = (argc == 2 && strcmp(argv[1], "check") == 0);
> > > +       bool wx = (argc == 2 && strcmp(argv[1], "wx") == 0);
> > > +
> > > +       page_size = sysconf(_SC_PAGESIZE);
> > > +       if (page_size <= 0) {
> > > +               fprintf(stderr, "failed to get pagesize, got %ld:  %s\n", page_size,
> > > +                       strerror(errno));
> > > +               return EXIT_FAILURE;
> > > +       }
> > > +
> > > +       fd = _memfd_secret(0);
> > > +       if (fd < 0) {
> > > +               printf("memfd_secret() failed:  %s\n", strerror(errno));
> > > +               if (check && errno != ENOSYS)
> > > +                       return EXIT_SUCCESS;
> > > +
> > > +               return EXIT_FAILURE;
> > > +       }
> > > +
> > > +       if (check)
> > > +               return EXIT_SUCCESS;
> > > +
> > > +       if (ftruncate(fd, page_size) < 0) {
> > > +               fprintf(stderr, "ftruncate failed:  %s\n", strerror(errno));
> > > +       }
> > > +
> > > +       flags = PROT_READ | PROT_WRITE;
> > > +       if (wx)
> > > +               flags |= PROT_EXEC;
> > > +
> > > +       mem = mmap(NULL, page_size, flags, MAP_SHARED, fd, 0);
> > > +       if (mem == MAP_FAILED || !mem) {
> > > +               printf("unable to mmap secret memory:  %s\n", strerror(errno));
> > > +               close(fd);
> > > +               return EXIT_FAILURE;
> > > +       }
> > > +
> > > +       close(fd);
> > > +
> > > +       memcpy(mem, TEXT, sizeof TEXT);
> >
> > Please use parentheses with sizeof. When the argument is a type name
> > they are mandatory so it's better to use them always for consistency.
> > See also:
> > https://lore.kernel.org/lkml/CA+55aFwey-q4716pYYSi=3R_ucw84zFspDXMXmzvzc72XSc9Lg@mail.gmail.com/
> > https://lore.kernel.org/lkml/CA+55aFwcJgAFiow1sSo7mkF9n0MpTw80gjAszazyBrRcmbph-g@mail.gmail.com/
> >
> > > +
> > > +       if (memcmp(mem, TEXT, sizeof TEXT) != 0) {
> > > +               fprintf(stderr, "data not synced (1)\n");
> > > +               munmap(mem, page_size);
> > > +               return EXIT_FAILURE;
> > > +       }
> > > +
> > > +       if (strlen(mem) + 1 != sizeof TEXT) {
> > > +               fprintf(stderr, "data not synced (2)\n");
> > > +               munmap(mem, page_size);
> > > +               return EXIT_FAILURE;
> > > +       }
> >
> > What is the point of this second check? The previous check already
> > asserts that the contents are char-to-char equal to TEXT (including
> > the terminating null character), which implies string length
> > equivalence as well.
> >
> > > +
> > > +       munmap(mem, page_size);
> > > +
> > > +       return EXIT_SUCCESS;
> > > +}
>
> You only pushed the updated version to the GitHub PR
> (https://github.com/SELinuxProject/selinux-testsuite/pull/80), but
> anyway I took that version and applied it (just removed the changelog
> from the commit message and added my SOB):
> https://github.com/SELinuxProject/selinux-testsuite/commit/77352e748f006c343d602e4be03ae0d2cfcca831
>

Thanks,
I thought I had sent the new revision, but it seems I have missed that.




>
> --
> Ondrej Mosnacek
> Senior Software Engineer, Linux Security - SELinux kernel
> Red Hat, Inc.
>

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2022-10-11 16:10 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-08-31 15:34 [PATCH v2] tests/secretmem: add test Christian Göttsche
2022-09-12 13:41 ` Ondrej Mosnacek
2022-10-11 14:02   ` Ondrej Mosnacek
2022-10-11 16:10     ` Christian Göttsche

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