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| author | Eric W. Biederman <ebiederm@xmission.com> | 2013-03-22 04:08:05 -0700 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2013-03-27 07:50:05 -0700 |
| commit | 132c94e31b8bca8ea921f9f96a57d684fa4ae0a9 (patch) | |
| tree | 52db12073a31f62301367416b2a3afec185975ef /fs/pnode.h | |
| parent | 90563b198e4c6674c63672fae1923da467215f45 (diff) | |
| download | lwn-132c94e31b8bca8ea921f9f96a57d684fa4ae0a9.tar.gz lwn-132c94e31b8bca8ea921f9f96a57d684fa4ae0a9.zip | |
vfs: Carefully propogate mounts across user namespaces
As a matter of policy MNT_READONLY should not be changable if the
original mounter had more privileges than creator of the mount
namespace.
Add the flag CL_UNPRIVILEGED to note when we are copying a mount from
a mount namespace that requires more privileges to a mount namespace
that requires fewer privileges.
When the CL_UNPRIVILEGED flag is set cause clone_mnt to set MNT_NO_REMOUNT
if any of the mnt flags that should never be changed are set.
This protects both mount propagation and the initial creation of a less
privileged mount namespace.
Cc: stable@vger.kernel.org
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'fs/pnode.h')
| -rw-r--r-- | fs/pnode.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/pnode.h b/fs/pnode.h index 19b853a3445c..a0493d5ebfbf 100644 --- a/fs/pnode.h +++ b/fs/pnode.h @@ -23,6 +23,7 @@ #define CL_MAKE_SHARED 0x08 #define CL_PRIVATE 0x10 #define CL_SHARED_TO_SLAVE 0x20 +#define CL_UNPRIVILEGED 0x40 static inline void set_mnt_shared(struct mount *mnt) { |