Re: [PATCH] selinux: Fix SBLABEL_MNT for NFS mounts
From: Tomeu Vizoso
Date: Thu Mar 30 2017 - 03:49:33 EST
On 29 March 2017 at 23:34, J. Bruce Fields <bfields@xxxxxxxxxx> wrote:
> On Wed, Mar 29, 2017 at 05:27:23PM +0200, Tomeu Vizoso wrote:
>> Labelling of files in a NFSv4.2 currently fails with ENOTSUPP because
>> the mount point doesn't have SBLABEL_MNT.
>> Add specific condition for NFS4 filesystems so it gets correctly
> Huh. Looking at the code, I think this is meant to be handled by the
> SECURITY_FS_USE_NATIVE case--there was a similar failure fixed some time
> ago by 9fc2b4b436cf. What kernel are you seeing this on? Is it a
> recent regression (in which case, what's the latest kernel that worked
> for you)?
I have seen this on 4.11-rc4, but I never tried to get this working before.
I will try to find time to see why SECURITY_FS_USE_NATIVE isn't working here.
>> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx>
>> Cc: J. Bruce Fields <bfields@xxxxxxxxxx>
>> cannot remotely say that I currently understand how selinux is expected
>> to work within NFS mounts, but this change allowed me to fully boot AOSP
>> with its rootfs and ramdisk on a single NFS share.
>> security/selinux/hooks.c | 1 +
>> 1 file changed, 1 insertion(+)
>> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
>> index 0c2ac318aa7f..71cd1d8c67c2 100644
>> --- a/security/selinux/hooks.c
>> +++ b/security/selinux/hooks.c
>> @@ -485,6 +485,7 @@ static int selinux_is_sblabel_mnt(struct super_block *sb)
>> !strcmp(sb->s_type->name, "debugfs") ||
>> !strcmp(sb->s_type->name, "tracefs") ||
>> !strcmp(sb->s_type->name, "rootfs") ||
>> + !strcmp(sb->s_type->name, "nfs4") ||
>> (selinux_policycap_cgroupseclabel &&
>> (!strcmp(sb->s_type->name, "cgroup") ||
>> !strcmp(sb->s_type->name, "cgroup2")));