| Message ID | d8a4d26e-46c8-975d-d075-a3848130981c@schaufler-ca.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, May 31, 2016 at 05:24:15PM -0700, Casey Schaufler wrote: > Subject: [PATCH] LSM: Fix for security_inode_getsecurity and -EOPNOTSUPP > > Serge Hallyn pointed out that the current implementation of > security_inode_getsecurity() works if there is only one hook > provided for it, but will fail if there is more than one and > the attribute requested isn't supplied by the first module. > This isn't a problem today, since only SELinux and Smack > provide this hook and there is (currently) no way to enable > both of those modules at the same time. Serge, however, wants > to introduce a capability attribute and an inode_getsecurity > hook in the capability security module to handle it. This > addresses that upcoming problem, will be required for "extreme > stacking" and is just a better implementation. > > Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Thanks, Casey. Acked-by: Serge Hallyn <serge@hallyn.com> > --- > > security/security.c | 29 +++++++++++++++++++++++++---- > 1 file changed, 25 insertions(+), 4 deletions(-) > > diff --git a/security/security.c b/security/security.c > index 3644b03..5a749ed 100644 > --- a/security/security.c > +++ b/security/security.c > @@ -699,18 +699,39 @@ int security_inode_killpriv(struct dentry *dentry) > > int security_inode_getsecurity(struct inode *inode, const char *name, void **buffer, bool alloc) > { > + struct security_hook_list *hp; > + int rc; > + > if (unlikely(IS_PRIVATE(inode))) > return -EOPNOTSUPP; > - return call_int_hook(inode_getsecurity, -EOPNOTSUPP, inode, name, > - buffer, alloc); > + /* > + * Only one module will provide an attribute with a given name. > + */ > + list_for_each_entry(hp, &security_hook_heads.inode_getsecurity, list) { > + rc = hp->hook.inode_getsecurity(inode, name, buffer, alloc); > + if (rc != -EOPNOTSUPP) > + return rc; > + } > + return -EOPNOTSUPP; > } > > int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags) > { > + struct security_hook_list *hp; > + int rc; > + > if (unlikely(IS_PRIVATE(inode))) > return -EOPNOTSUPP; > - return call_int_hook(inode_setsecurity, -EOPNOTSUPP, inode, name, > - value, size, flags); > + /* > + * Only one module will provide an attribute with a given name. > + */ > + list_for_each_entry(hp, &security_hook_heads.inode_setsecurity, list) { > + rc = hp->hook.inode_setsecurity(inode, name, value, size, > + flags); > + if (rc != -EOPNOTSUPP) > + return rc; > + } > + return -EOPNOTSUPP; > } > > int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) -- 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
On Tue, 31 May 2016, Casey Schaufler wrote: > Subject: [PATCH] LSM: Fix for security_inode_getsecurity and -EOPNOTSUPP > > Serge Hallyn pointed out that the current implementation of > security_inode_getsecurity() works if there is only one hook > provided for it, but will fail if there is more than one and > the attribute requested isn't supplied by the first module. > This isn't a problem today, since only SELinux and Smack > provide this hook and there is (currently) no way to enable > both of those modules at the same time. Serge, however, wants > to introduce a capability attribute and an inode_getsecurity > hook in the capability security module to handle it. This > addresses that upcoming problem, will be required for "extreme > stacking" and is just a better implementation. > > Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Applied to git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security.git next
diff --git a/security/security.c b/security/security.c index 3644b03..5a749ed 100644 --- a/security/security.c +++ b/security/security.c @@ -699,18 +699,39 @@ int security_inode_killpriv(struct dentry *dentry) int security_inode_getsecurity(struct inode *inode, const char *name, void **buffer, bool alloc) { + struct security_hook_list *hp; + int rc; + if (unlikely(IS_PRIVATE(inode))) return -EOPNOTSUPP; - return call_int_hook(inode_getsecurity, -EOPNOTSUPP, inode, name, - buffer, alloc); + /* + * Only one module will provide an attribute with a given name. + */ + list_for_each_entry(hp, &security_hook_heads.inode_getsecurity, list) { + rc = hp->hook.inode_getsecurity(inode, name, buffer, alloc); + if (rc != -EOPNOTSUPP) + return rc; + } + return -EOPNOTSUPP; } int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags) { + struct security_hook_list *hp; + int rc; + if (unlikely(IS_PRIVATE(inode))) return -EOPNOTSUPP; - return call_int_hook(inode_setsecurity, -EOPNOTSUPP, inode, name, - value, size, flags); + /* + * Only one module will provide an attribute with a given name. + */ + list_for_each_entry(hp, &security_hook_heads.inode_setsecurity, list) { + rc = hp->hook.inode_setsecurity(inode, name, value, size, + flags); + if (rc != -EOPNOTSUPP) + return rc; + } + return -EOPNOTSUPP; } int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
Subject: [PATCH] LSM: Fix for security_inode_getsecurity and -EOPNOTSUPP Serge Hallyn pointed out that the current implementation of security_inode_getsecurity() works if there is only one hook provided for it, but will fail if there is more than one and the attribute requested isn't supplied by the first module. This isn't a problem today, since only SELinux and Smack provide this hook and there is (currently) no way to enable both of those modules at the same time. Serge, however, wants to introduce a capability attribute and an inode_getsecurity hook in the capability security module to handle it. This addresses that upcoming problem, will be required for "extreme stacking" and is just a better implementation. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> --- security/security.c | 29 +++++++++++++++++++++++++---- 1 file changed, 25 insertions(+), 4 deletions(-) -- 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