diff mbox series

linux: return UNSUPPORTED in tst-mount if support_become_root fails

Message ID 20220714032325.3899142-1-michael.hudson@canonical.com
State Superseded
Headers
Series linux: return UNSUPPORTED in tst-mount if support_become_root fails |

Checks

Context Check Description
dj/TryBot-32bit success Build for i686
dj/TryBot-apply_patch success Patch applied to master at the time it was sent

Commit Message

Michael Hudson-Doyle July 14, 2022, 3:23 a.m. UTC 
  Otherwise the test fails if run in a chroot by a non-root user:

warning: could not become root outside namespace (Operation not permitted)
../sysdeps/unix/sysv/linux/tst-mount.c:36: numeric comparison failure
   left: 1 (0x1); from: errno
  right: 19 (0x13); from: ENODEV
error: ../sysdeps/unix/sysv/linux/tst-mount.c:39: not true: fd != -1
error: ../sysdeps/unix/sysv/linux/tst-mount.c:46: not true: r != -1
error: ../sysdeps/unix/sysv/linux/tst-mount.c:48: not true: r != -1
../sysdeps/unix/sysv/linux/tst-mount.c:52: numeric comparison failure
   left: 1 (0x1); from: errno
  right: 9 (0x9); from: EBADF
error: ../sysdeps/unix/sysv/linux/tst-mount.c:55: not true: mfd != -1
../sysdeps/unix/sysv/linux/tst-mount.c:58: numeric comparison failure
   left: 1 (0x1); from: errno
  right: 2 (0x2); from: ENOENT
error: ../sysdeps/unix/sysv/linux/tst-mount.c:61: not true: r != -1
../sysdeps/unix/sysv/linux/tst-mount.c:65: numeric comparison failure
   left: 1 (0x1); from: errno
  right: 2 (0x2); from: ENOENT
error: ../sysdeps/unix/sysv/linux/tst-mount.c:68: not true: pfd != -1
error: ../sysdeps/unix/sysv/linux/tst-mount.c:75: not true: fd_tree != -1
../sysdeps/unix/sysv/linux/tst-mount.c:88: numeric comparison failure
   left: 1 (0x1); from: errno
  right: 38 (0x26); from: ENOSYS
error: 12 test failures
---
 sysdeps/unix/sysv/linux/tst-mount.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Adhemerval Zanella Netto July 14, 2022, 11:24 a.m. UTC | #1 
On 14/07/22 00:23, Michael Hudson-Doyle via Libc-alpha wrote:
> Otherwise the test fails if run in a chroot by a non-root user:
> 
> warning: could not become root outside namespace (Operation not permitted)
> ../sysdeps/unix/sysv/linux/tst-mount.c:36: numeric comparison failure
>    left: 1 (0x1); from: errno
>   right: 19 (0x13); from: ENODEV
> error: ../sysdeps/unix/sysv/linux/tst-mount.c:39: not true: fd != -1
> error: ../sysdeps/unix/sysv/linux/tst-mount.c:46: not true: r != -1
> error: ../sysdeps/unix/sysv/linux/tst-mount.c:48: not true: r != -1
> ../sysdeps/unix/sysv/linux/tst-mount.c:52: numeric comparison failure
>    left: 1 (0x1); from: errno
>   right: 9 (0x9); from: EBADF
> error: ../sysdeps/unix/sysv/linux/tst-mount.c:55: not true: mfd != -1
> ../sysdeps/unix/sysv/linux/tst-mount.c:58: numeric comparison failure
>    left: 1 (0x1); from: errno
>   right: 2 (0x2); from: ENOENT
> error: ../sysdeps/unix/sysv/linux/tst-mount.c:61: not true: r != -1
> ../sysdeps/unix/sysv/linux/tst-mount.c:65: numeric comparison failure
>    left: 1 (0x1); from: errno
>   right: 2 (0x2); from: ENOENT
> error: ../sysdeps/unix/sysv/linux/tst-mount.c:68: not true: pfd != -1
> error: ../sysdeps/unix/sysv/linux/tst-mount.c:75: not true: fd_tree != -1
> ../sysdeps/unix/sysv/linux/tst-mount.c:88: numeric comparison failure
>    left: 1 (0x1); from: errno
>   right: 38 (0x26); from: ENOSYS
> error: 12 test failures
> ---
>  sysdeps/unix/sysv/linux/tst-mount.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/sysdeps/unix/sysv/linux/tst-mount.c b/sysdeps/unix/sysv/linux/tst-mount.c
> index 502d7e3433..bd75c9e704 100644
> --- a/sysdeps/unix/sysv/linux/tst-mount.c
> +++ b/sysdeps/unix/sysv/linux/tst-mount.c
> @@ -103,7 +103,8 @@ subprocess (void)
>  static int
>  do_test (void)
>  {
> -  support_become_root ();
> +  if (!support_become_root ())
> +    FAIL_UNSUPPORTED("could not become root");
>  

I think the usual way is to check if process can chroot:

  support_become_root ();
  if (!support_can_chroot ())
    return EXIT_UNSUPPORTED;

As done by other tests.

>    pid_t pid = xfork ();
>    if (pid == 0)
Carlos O'Donell July 14, 2022, 7:03 p.m. UTC | #2 
On 7/14/22 07:24, Adhemerval Zanella Netto via Libc-alpha wrote:
> 
> 
> On 14/07/22 00:23, Michael Hudson-Doyle via Libc-alpha wrote:
>> Otherwise the test fails if run in a chroot by a non-root user:
>>
>> warning: could not become root outside namespace (Operation not permitted)
>> ../sysdeps/unix/sysv/linux/tst-mount.c:36: numeric comparison failure
>>    left: 1 (0x1); from: errno
>>   right: 19 (0x13); from: ENODEV
>> error: ../sysdeps/unix/sysv/linux/tst-mount.c:39: not true: fd != -1
>> error: ../sysdeps/unix/sysv/linux/tst-mount.c:46: not true: r != -1
>> error: ../sysdeps/unix/sysv/linux/tst-mount.c:48: not true: r != -1
>> ../sysdeps/unix/sysv/linux/tst-mount.c:52: numeric comparison failure
>>    left: 1 (0x1); from: errno
>>   right: 9 (0x9); from: EBADF
>> error: ../sysdeps/unix/sysv/linux/tst-mount.c:55: not true: mfd != -1
>> ../sysdeps/unix/sysv/linux/tst-mount.c:58: numeric comparison failure
>>    left: 1 (0x1); from: errno
>>   right: 2 (0x2); from: ENOENT
>> error: ../sysdeps/unix/sysv/linux/tst-mount.c:61: not true: r != -1
>> ../sysdeps/unix/sysv/linux/tst-mount.c:65: numeric comparison failure
>>    left: 1 (0x1); from: errno
>>   right: 2 (0x2); from: ENOENT
>> error: ../sysdeps/unix/sysv/linux/tst-mount.c:68: not true: pfd != -1
>> error: ../sysdeps/unix/sysv/linux/tst-mount.c:75: not true: fd_tree != -1
>> ../sysdeps/unix/sysv/linux/tst-mount.c:88: numeric comparison failure
>>    left: 1 (0x1); from: errno
>>   right: 38 (0x26); from: ENOSYS
>> error: 12 test failures
>> ---
>>  sysdeps/unix/sysv/linux/tst-mount.c | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/sysdeps/unix/sysv/linux/tst-mount.c b/sysdeps/unix/sysv/linux/tst-mount.c
>> index 502d7e3433..bd75c9e704 100644
>> --- a/sysdeps/unix/sysv/linux/tst-mount.c
>> +++ b/sysdeps/unix/sysv/linux/tst-mount.c
>> @@ -103,7 +103,8 @@ subprocess (void)
>>  static int
>>  do_test (void)
>>  {
>> -  support_become_root ();
>> +  if (!support_become_root ())
>> +    FAIL_UNSUPPORTED("could not become root");
>>  
> 
> I think the usual way is to check if process can chroot:
> 
>   support_become_root ();
>   if (!support_can_chroot ())
>     return EXIT_UNSUPPORTED;
> 
> As done by other tests.

Agreed. We need this same fix for Fedora. I didn't catch this in my review.
 
>>    pid_t pid = xfork ();
>>    if (pid == 0)
>
DJ Delorie July 14, 2022, 7:18 p.m. UTC | #3 
Michael Hudson-Doyle via Libc-alpha <libc-alpha@sourceware.org> writes:
> Otherwise the test fails if run in a chroot by a non-root user:

Can this test run in the test-container container?  I'm wondering if
there's some subtle difference between support_become_root() and a more
complete containerization that might enable it to run in more cases.

(yes, I know the test-container might not have tmpfs pre-mounted.  But
then again, not all real systems will either)
Michael Hudson-Doyle July 14, 2022, 10:50 p.m. UTC | #4 
On Fri, 15 Jul 2022 at 07:19, DJ Delorie <dj@redhat.com> wrote:

>
> Michael Hudson-Doyle via Libc-alpha <libc-alpha@sourceware.org> writes:
> > Otherwise the test fails if run in a chroot by a non-root user:
>
> Can this test run in the test-container container?  I'm wondering if
> there's some subtle difference between support_become_root() and a more
> complete containerization that might enable it to run in more cases.
>

All the test-container tests in Ubuntu builds end up UNSUPPORTED with

test-container.c:1130: unable to unshare user/fs: Operation not permitted

so that wouldn't really help here (I should probably look into why this is).

Cheers,
mwh

(yes, I know the test-container might not have tmpfs pre-mounted.  But
> then again, not all real systems will either)
>
>
DJ Delorie July 14, 2022, 11:16 p.m. UTC | #5 
Michael Hudson-Doyle <michael.hudson@canonical.com> writes:
> All the test-container tests in Ubuntu builds end up UNSUPPORTED with
> test-container.c:1130: unable to unshare user/fs: Operation not permitted
> so that wouldn't really help here (I should probably look into why this is).

Yeah, Debian-based distros default to disabling user containers.  There
should be a hint printed as to how to re-enable them, but that's on a
per-system basis, and up to the admin.
diff mbox series

Patch

diff --git a/sysdeps/unix/sysv/linux/tst-mount.c b/sysdeps/unix/sysv/linux/tst-mount.c
index 502d7e3433..bd75c9e704 100644
--- a/sysdeps/unix/sysv/linux/tst-mount.c
+++ b/sysdeps/unix/sysv/linux/tst-mount.c
@@ -103,7 +103,8 @@  subprocess (void)
 static int
 do_test (void)
 {
-  support_become_root ();
+  if (!support_become_root ())
+    FAIL_UNSUPPORTED("could not become root");
 
   pid_t pid = xfork ();
   if (pid == 0)