| Message ID | 1449070821-73820-12-git-send-email-seth.forshee@canonical.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
Quoting Seth Forshee (seth.forshee@canonical.com): > The mounter of a filesystem should be privileged towards the > inodes of that filesystem. Extend the checks in > inode_owner_or_capable() and capable_wrt_inode_uidgid() to > permit access by users priviliged in the user namespace of the > inode's superblock. > > Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> > --- > fs/inode.c | 3 +++ > kernel/capability.c | 13 +++++++++---- > 2 files changed, 12 insertions(+), 4 deletions(-) > > diff --git a/fs/inode.c b/fs/inode.c > index 1be5f9003eb3..01c036fe1950 100644 > --- a/fs/inode.c > +++ b/fs/inode.c > @@ -1962,6 +1962,9 @@ bool inode_owner_or_capable(const struct inode *inode) > ns = current_user_ns(); > if (ns_capable(ns, CAP_FOWNER) && kuid_has_mapping(ns, inode->i_uid)) > return true; > + > + if (ns_capable(inode->i_sb->s_user_ns, CAP_FOWNER)) > + return true; > return false; > } > EXPORT_SYMBOL(inode_owner_or_capable); > diff --git a/kernel/capability.c b/kernel/capability.c > index 45432b54d5c6..5137a38a5670 100644 > --- a/kernel/capability.c > +++ b/kernel/capability.c > @@ -437,13 +437,18 @@ EXPORT_SYMBOL(file_ns_capable); > * > * Return true if the current task has the given capability targeted at > * its own user namespace and that the given inode's uid and gid are > - * mapped into the current user namespace. > + * mapped into the current user namespace, or if the current task has > + * the capability towards the user namespace of the inode's superblock. > */ > bool capable_wrt_inode_uidgid(const struct inode *inode, int cap) > { > - struct user_namespace *ns = current_user_ns(); > + struct user_namespace *ns; > > - return ns_capable(ns, cap) && kuid_has_mapping(ns, inode->i_uid) && > - kgid_has_mapping(ns, inode->i_gid); > + ns = current_user_ns(); > + if (ns_capable(ns, cap) && kuid_has_mapping(ns, inode->i_uid) && > + kgid_has_mapping(ns, inode->i_gid)) > + return true; > + > + return ns_capable(inode->i_sb->s_user_ns, cap); > } > EXPORT_SYMBOL(capable_wrt_inode_uidgid); > -- > 1.9.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
diff --git a/fs/inode.c b/fs/inode.c index 1be5f9003eb3..01c036fe1950 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -1962,6 +1962,9 @@ bool inode_owner_or_capable(const struct inode *inode) ns = current_user_ns(); if (ns_capable(ns, CAP_FOWNER) && kuid_has_mapping(ns, inode->i_uid)) return true; + + if (ns_capable(inode->i_sb->s_user_ns, CAP_FOWNER)) + return true; return false; } EXPORT_SYMBOL(inode_owner_or_capable); diff --git a/kernel/capability.c b/kernel/capability.c index 45432b54d5c6..5137a38a5670 100644 --- a/kernel/capability.c +++ b/kernel/capability.c @@ -437,13 +437,18 @@ EXPORT_SYMBOL(file_ns_capable); * * Return true if the current task has the given capability targeted at * its own user namespace and that the given inode's uid and gid are - * mapped into the current user namespace. + * mapped into the current user namespace, or if the current task has + * the capability towards the user namespace of the inode's superblock. */ bool capable_wrt_inode_uidgid(const struct inode *inode, int cap) { - struct user_namespace *ns = current_user_ns(); + struct user_namespace *ns; - return ns_capable(ns, cap) && kuid_has_mapping(ns, inode->i_uid) && - kgid_has_mapping(ns, inode->i_gid); + ns = current_user_ns(); + if (ns_capable(ns, cap) && kuid_has_mapping(ns, inode->i_uid) && + kgid_has_mapping(ns, inode->i_gid)) + return true; + + return ns_capable(inode->i_sb->s_user_ns, cap); } EXPORT_SYMBOL(capable_wrt_inode_uidgid);
The mounter of a filesystem should be privileged towards the inodes of that filesystem. Extend the checks in inode_owner_or_capable() and capable_wrt_inode_uidgid() to permit access by users priviliged in the user namespace of the inode's superblock. Signed-off-by: Seth Forshee <seth.forshee@canonical.com> --- fs/inode.c | 3 +++ kernel/capability.c | 13 +++++++++---- 2 files changed, 12 insertions(+), 4 deletions(-)