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-rw-r--r--include/linux/capability.h7
-rw-r--r--security/commoncap.c129
2 files changed, 78 insertions, 58 deletions
diff --git a/include/linux/capability.h b/include/linux/capability.h
index b5750d0b96e0..d567af247ed8 100644
--- a/include/linux/capability.h
+++ b/include/linux/capability.h
@@ -99,6 +99,13 @@ typedef struct kernel_cap_struct {
__u32 cap[_KERNEL_CAPABILITY_U32S];
} kernel_cap_t;
+/* exact same as vfs_cap_data but in cpu endian and always filled completely */
+struct cpu_vfs_cap_data {
+ __u32 magic_etc;
+ kernel_cap_t permitted;
+ kernel_cap_t inheritable;
+};
+
#define _USER_CAP_HEADER_SIZE (sizeof(struct __user_cap_header_struct))
#define _KERNEL_CAP_T_SIZE (sizeof(kernel_cap_t))
diff --git a/security/commoncap.c b/security/commoncap.c
index f88119cb2bc2..d7eff5797b91 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -202,17 +202,70 @@ int cap_inode_killpriv(struct dentry *dentry)
return inode->i_op->removexattr(dentry, XATTR_NAME_CAPS);
}
-static inline int cap_from_disk(struct vfs_cap_data *caps,
- struct linux_binprm *bprm, unsigned size)
+static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data *caps,
+ struct linux_binprm *bprm)
{
+ unsigned i;
+ int ret = 0;
+
+ if (caps->magic_etc & VFS_CAP_FLAGS_EFFECTIVE)
+ bprm->cap_effective = true;
+ else
+ bprm->cap_effective = false;
+
+ CAP_FOR_EACH_U32(i) {
+ __u32 permitted = caps->permitted.cap[i];
+ __u32 inheritable = caps->inheritable.cap[i];
+
+ /*
+ * pP' = (X & fP) | (pI & fI)
+ */
+ bprm->cap_post_exec_permitted.cap[i] =
+ (current->cap_bset.cap[i] & permitted) |
+ (current->cap_inheritable.cap[i] & inheritable);
+
+ if (permitted & ~bprm->cap_post_exec_permitted.cap[i]) {
+ /*
+ * insufficient to execute correctly
+ */
+ ret = -EPERM;
+ }
+ }
+
+ /*
+ * For legacy apps, with no internal support for recognizing they
+ * do not have enough capabilities, we return an error if they are
+ * missing some "forced" (aka file-permitted) capabilities.
+ */
+ return bprm->cap_effective ? ret : 0;
+}
+
+int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps)
+{
+ struct inode *inode = dentry->d_inode;
__u32 magic_etc;
unsigned tocopy, i;
- int ret;
+ int size;
+ struct vfs_cap_data caps;
+
+ memset(cpu_caps, 0, sizeof(struct cpu_vfs_cap_data));
+
+ if (!inode || !inode->i_op || !inode->i_op->getxattr)
+ return -ENODATA;
+
+ size = inode->i_op->getxattr((struct dentry *)dentry, XATTR_NAME_CAPS, &caps,
+ XATTR_CAPS_SZ);
+ if (size == -ENODATA || size == -EOPNOTSUPP) {
+ /* no data, that's ok */
+ return -ENODATA;
+ }
+ if (size < 0)
+ return size;
if (size < sizeof(magic_etc))
return -EINVAL;
- magic_etc = le32_to_cpu(caps->magic_etc);
+ cpu_caps->magic_etc = magic_etc = le32_to_cpu(caps.magic_etc);
switch ((magic_etc & VFS_CAP_REVISION_MASK)) {
case VFS_CAP_REVISION_1:
@@ -229,46 +282,13 @@ static inline int cap_from_disk(struct vfs_cap_data *caps,
return -EINVAL;
}
- if (magic_etc & VFS_CAP_FLAGS_EFFECTIVE) {
- bprm->cap_effective = true;
- } else {
- bprm->cap_effective = false;
- }
-
- ret = 0;
-
CAP_FOR_EACH_U32(i) {
- __u32 value_cpu;
-
- if (i >= tocopy) {
- /*
- * Legacy capability sets have no upper bits
- */
- bprm->cap_post_exec_permitted.cap[i] = 0;
- continue;
- }
- /*
- * pP' = (X & fP) | (pI & fI)
- */
- value_cpu = le32_to_cpu(caps->data[i].permitted);
- bprm->cap_post_exec_permitted.cap[i] =
- (current->cap_bset.cap[i] & value_cpu) |
- (current->cap_inheritable.cap[i] &
- le32_to_cpu(caps->data[i].inheritable));
- if (value_cpu & ~bprm->cap_post_exec_permitted.cap[i]) {
- /*
- * insufficient to execute correctly
- */
- ret = -EPERM;
- }
+ if (i >= tocopy)
+ break;
+ cpu_caps->permitted.cap[i] = le32_to_cpu(caps.data[i].permitted);
+ cpu_caps->inheritable.cap[i] = le32_to_cpu(caps.data[i].inheritable);
}
-
- /*
- * For legacy apps, with no internal support for recognizing they
- * do not have enough capabilities, we return an error if they are
- * missing some "forced" (aka file-permitted) capabilities.
- */
- return bprm->cap_effective ? ret : 0;
+ return 0;
}
/* Locate any VFS capabilities: */
@@ -276,8 +296,7 @@ static int get_file_caps(struct linux_binprm *bprm)
{
struct dentry *dentry;
int rc = 0;
- struct vfs_cap_data vcaps;
- struct inode *inode;
+ struct cpu_vfs_cap_data vcaps;
bprm_clear_caps(bprm);
@@ -288,24 +307,18 @@ static int get_file_caps(struct linux_binprm *bprm)
return 0;
dentry = dget(bprm->file->f_dentry);
- inode = dentry->d_inode;
- if (!inode->i_op || !inode->i_op->getxattr)
- goto out;
- rc = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, &vcaps,
- XATTR_CAPS_SZ);
- if (rc == -ENODATA || rc == -EOPNOTSUPP) {
- /* no data, that's ok */
- rc = 0;
+ rc = get_vfs_caps_from_disk(dentry, &vcaps);
+ if (rc < 0) {
+ if (rc == -EINVAL)
+ printk(KERN_NOTICE "%s: get_vfs_caps_from_disk returned %d for %s\n",
+ __func__, rc, bprm->filename);
+ else if (rc == -ENODATA)
+ rc = 0;
goto out;
}
- if (rc < 0)
- goto out;
- rc = cap_from_disk(&vcaps, bprm, rc);
- if (rc == -EINVAL)
- printk(KERN_NOTICE "%s: cap_from_disk returned %d for %s\n",
- __func__, rc, bprm->filename);
+ rc = bprm_caps_from_vfs_caps(&vcaps, bprm);
out:
dput(dentry);