Re: [PATCH 1/1] security: introduce fs caps

From: Serge E. Hallyn
Date: Thu Nov 09 2006 - 01:21:13 EST


Sorry, I should have noticed and fixed this much sooner. This
patch is against the latest full fscaps patch which I'm replying
to.

From: Serge E. Hallyn <serue@xxxxxxxxxx>
Date: Thu, 9 Nov 2006 00:01:49 -0600
Subject: security: file caps: fix unused variable warnings

Address warnings of unused variables at cap_bprm_set_security
when file capabilities are disabled, and simultaneously clean
up the code a little, by pulling the new code into a helper
function.

Rename vfs_cap_data_struct to remove redundant '_struct'.

Signed-off-by: Serge E. Hallyn <serue@xxxxxxxxxx>
---
security/commoncap.c | 73 ++++++++++++++++++++++++++++----------------------
1 files changed, 41 insertions(+), 32 deletions(-)

diff --git a/security/commoncap.c b/security/commoncap.c
index 6f5e46c..4b50b4d 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -109,16 +109,17 @@ void cap_capset_set (struct task_struct
target->cap_permitted = *permitted;
}

+#ifdef CONFIG_SECURITY_FS_CAPABILITIES
#define XATTR_CAPS_SUFFIX "capability"
#define XATTR_NAME_CAPS XATTR_SECURITY_PREFIX XATTR_CAPS_SUFFIX
-struct vfs_cap_data_struct {
+struct vfs_cap_data {
__u32 version;
__u32 effective;
__u32 permitted;
__u32 inheritable;
};

-static inline void convert_to_le(struct vfs_cap_data_struct *cap)
+static inline void convert_to_le(struct vfs_cap_data *cap)
{
cap->version = le32_to_cpu(cap->version);
cap->effective = le32_to_cpu(cap->effective);
@@ -126,7 +127,7 @@ static inline void convert_to_le(struct
cap->inheritable = le32_to_cpu(cap->inheritable);
}

-static int check_cap_sanity(struct vfs_cap_data_struct *cap)
+static int check_cap_sanity(struct vfs_cap_data *cap)
{
int i;

@@ -149,39 +150,14 @@ static int check_cap_sanity(struct vfs_c
return 0;
}

-int cap_bprm_set_security (struct linux_binprm *bprm)
+/* Locate any VFS capabilities: */
+static int set_file_caps(struct linux_binprm *bprm)
{
struct dentry *dentry;
ssize_t rc;
- struct vfs_cap_data_struct cap_struct;
+ struct vfs_cap_data cap_struct;
struct inode *inode;

- /* Copied from fs/exec.c:prepare_binprm. */
-
- cap_clear (bprm->cap_inheritable);
- cap_clear (bprm->cap_permitted);
- cap_clear (bprm->cap_effective);
-
- /* To support inheritance of root-permissions and suid-root
- * executables under compatibility mode, we raise all three
- * capability sets for the file.
- *
- * If only the real uid is 0, we only raise the inheritable
- * and permitted sets of the executable file.
- */
-
- if (!issecure (SECURE_NOROOT)) {
- if (bprm->e_uid == 0 || current->uid == 0) {
- cap_set_full (bprm->cap_inheritable);
- cap_set_full (bprm->cap_permitted);
- }
- if (bprm->e_uid == 0)
- cap_set_full (bprm->cap_effective);
- }
-
-#ifdef CONFIG_SECURITY_FS_CAPABILITIES
- /* Locate any VFS capabilities: */
-
dentry = dget(bprm->file->f_dentry);
inode = dentry->d_inode;
if (!inode->i_op || !inode->i_op->getxattr) {
@@ -216,9 +192,42 @@ #ifdef CONFIG_SECURITY_FS_CAPABILITIES
bprm->cap_permitted = cap_struct.permitted;
bprm->cap_inheritable = cap_struct.inheritable;

-#endif
return 0;
}
+#else
+static int set_file_caps(struct linux_binprm *bprm)
+{
+ return 0;
+}
+#endif
+
+int cap_bprm_set_security (struct linux_binprm *bprm)
+{
+ /* Copied from fs/exec.c:prepare_binprm. */
+
+ cap_clear (bprm->cap_inheritable);
+ cap_clear (bprm->cap_permitted);
+ cap_clear (bprm->cap_effective);
+
+ /* To support inheritance of root-permissions and suid-root
+ * executables under compatibility mode, we raise all three
+ * capability sets for the file.
+ *
+ * If only the real uid is 0, we only raise the inheritable
+ * and permitted sets of the executable file.
+ */
+
+ if (!issecure (SECURE_NOROOT)) {
+ if (bprm->e_uid == 0 || current->uid == 0) {
+ cap_set_full (bprm->cap_inheritable);
+ cap_set_full (bprm->cap_permitted);
+ }
+ if (bprm->e_uid == 0)
+ cap_set_full (bprm->cap_effective);
+ }
+
+ return set_file_caps(bprm);
+}

void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe)
{
--
1.4.1

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