| Message ID | 20150618133254.12722.33339.stgit@warthog.procyon.org.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 06/18/2015 09:32 AM, David Howells wrote: > Provide stubs for union/overlay copy-up handling. The xattr copy up stub > discards lower SELinux xattrs rather than letting them be copied up so that > the security label on the copy doesn't get corrupted. > > Signed-off-by: David Howells <dhowells@redhat.com> > --- > > security/selinux/hooks.c | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c > index ffa5a642629a..c5d893e2ff23 100644 > --- a/security/selinux/hooks.c > +++ b/security/selinux/hooks.c > @@ -3200,6 +3200,20 @@ static void selinux_inode_getsecid(const struct inode *inode, u32 *secid) > *secid = isec->sid; > } > > +static int selinux_inode_copy_up(struct dentry *src, struct dentry *dst) > +{ > + return 0; > +} > + > +static int selinux_inode_copy_up_xattr(struct dentry *src, struct dentry *dst, > + const char *name, void *value, > + size_t *size) > +{ > + if (strcmp(name, XATTR_NAME_SELINUX) == 0) > + return 1; /* Discard */ > + return 0; > +} > + (expanded cc list) I'm not sure we never want to copy up the SELinux attribute. See my other email about ecryptfs and supporting per-file labeling and consistent access control over the upper and lower inodes. > /* file security operations */ > > static int selinux_revalidate_file_permission(struct file *file, int mask) > @@ -5917,6 +5931,8 @@ static struct security_operations selinux_ops = { > .inode_setsecurity = selinux_inode_setsecurity, > .inode_listsecurity = selinux_inode_listsecurity, > .inode_getsecid = selinux_inode_getsecid, > + .inode_copy_up = selinux_inode_copy_up, > + .inode_copy_up_xattr = selinux_inode_copy_up_xattr, > > .file_permission = selinux_file_permission, > .file_alloc_security = selinux_file_alloc_security, > > -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 6/18/2015 6:32 AM, David Howells wrote: > Provide stubs for union/overlay copy-up handling. The xattr copy up stub > discards lower SELinux xattrs rather than letting them be copied up so that > the security label on the copy doesn't get corrupted. Are you planning to do this for Smack, too? > > Signed-off-by: David Howells <dhowells@redhat.com> > --- > > security/selinux/hooks.c | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c > index ffa5a642629a..c5d893e2ff23 100644 > --- a/security/selinux/hooks.c > +++ b/security/selinux/hooks.c > @@ -3200,6 +3200,20 @@ static void selinux_inode_getsecid(const struct inode *inode, u32 *secid) > *secid = isec->sid; > } > > +static int selinux_inode_copy_up(struct dentry *src, struct dentry *dst) > +{ > + return 0; > +} > + > +static int selinux_inode_copy_up_xattr(struct dentry *src, struct dentry *dst, > + const char *name, void *value, > + size_t *size) > +{ > + if (strcmp(name, XATTR_NAME_SELINUX) == 0) > + return 1; /* Discard */ > + return 0; > +} > + > /* file security operations */ > > static int selinux_revalidate_file_permission(struct file *file, int mask) > @@ -5917,6 +5931,8 @@ static struct security_operations selinux_ops = { > .inode_setsecurity = selinux_inode_setsecurity, > .inode_listsecurity = selinux_inode_listsecurity, > .inode_getsecid = selinux_inode_getsecid, > + .inode_copy_up = selinux_inode_copy_up, > + .inode_copy_up_xattr = selinux_inode_copy_up_xattr, > > .file_permission = selinux_file_permission, > .file_alloc_security = selinux_file_alloc_security, > > -- > To unsubscribe from this list: send the line "unsubscribe linux-security-module" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Stephen Smalley <sds@tycho.nsa.gov> wrote: > I'm not sure we never want to copy up the SELinux attribute. See my > other email about ecryptfs and supporting per-file labeling and > consistent access control over the upper and lower inodes. Yes. That's why there are two operations. inode_copy_up() should set the label appropriately and inode_copy_up_xattr() should prevent the label set by inode_copy_up() from being clobbered. Note that inode_copy_up() has access to the lower file label and can perform some sort of incantation to transmute it before applying it. David -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index ffa5a642629a..c5d893e2ff23 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3200,6 +3200,20 @@ static void selinux_inode_getsecid(const struct inode *inode, u32 *secid) *secid = isec->sid; } +static int selinux_inode_copy_up(struct dentry *src, struct dentry *dst) +{ + return 0; +} + +static int selinux_inode_copy_up_xattr(struct dentry *src, struct dentry *dst, + const char *name, void *value, + size_t *size) +{ + if (strcmp(name, XATTR_NAME_SELINUX) == 0) + return 1; /* Discard */ + return 0; +} + /* file security operations */ static int selinux_revalidate_file_permission(struct file *file, int mask) @@ -5917,6 +5931,8 @@ static struct security_operations selinux_ops = { .inode_setsecurity = selinux_inode_setsecurity, .inode_listsecurity = selinux_inode_listsecurity, .inode_getsecid = selinux_inode_getsecid, + .inode_copy_up = selinux_inode_copy_up, + .inode_copy_up_xattr = selinux_inode_copy_up_xattr, .file_permission = selinux_file_permission, .file_alloc_security = selinux_file_alloc_security,
Provide stubs for union/overlay copy-up handling. The xattr copy up stub discards lower SELinux xattrs rather than letting them be copied up so that the security label on the copy doesn't get corrupted. Signed-off-by: David Howells <dhowells@redhat.com> --- security/selinux/hooks.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html