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| author | Seth Forshee <seth.forshee@canonical.com> | 2016-04-26 21:36:25 +0200 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2016-06-28 04:58:25 +0200 |
| commit | a475acf01f79e89a1a5845733e10108d80f77188 (patch) | |
| tree | 69c43e9a9ae185e8c7f0469c1c3695acd0712104 /fs/attr.c | |
| parent | selinux: Add support for unprivileged mounts from user namespaces (diff) | |
| download | linux-a475acf01f79e89a1a5845733e10108d80f77188.tar.xz linux-a475acf01f79e89a1a5845733e10108d80f77188.zip | |
fs: Refuse uid/gid changes which don't map into s_user_ns
Add checks to notify_change to verify that uid and gid changes
will map into the superblock's user namespace. If they do not
fail with -EOVERFLOW.
This is mandatory so that fileystems don't have to even think
of dealing with ia_uid and ia_gid that
--EWB Moved the test from inode_change_ok to notify_change
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Diffstat (limited to 'fs/attr.c')
| -rw-r--r-- | fs/attr.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/fs/attr.c b/fs/attr.c index 25b24d0f6c88..dd723578ddce 100644 --- a/fs/attr.c +++ b/fs/attr.c @@ -255,6 +255,17 @@ int notify_change(struct dentry * dentry, struct iattr * attr, struct inode **de if (!(attr->ia_valid & ~(ATTR_KILL_SUID | ATTR_KILL_SGID))) return 0; + /* + * Verify that uid/gid changes are valid in the target + * namespace of the superblock. + */ + if (ia_valid & ATTR_UID && + !kuid_has_mapping(inode->i_sb->s_user_ns, attr->ia_uid)) + return -EOVERFLOW; + if (ia_valid & ATTR_GID && + !kgid_has_mapping(inode->i_sb->s_user_ns, attr->ia_gid)) + return -EOVERFLOW; + error = security_inode_setattr(dentry, attr); if (error) return error; |