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-rw-r--r--security/commoncap.c67
1 files changed, 43 insertions, 24 deletions
diff --git a/security/commoncap.c b/security/commoncap.c
index bacc1111d871..26c1cb725dcb 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -371,10 +371,11 @@ int cap_inode_getsecurity(struct inode *inode, const char *name, void **buffer,
{
int size, ret;
kuid_t kroot;
+ u32 nsmagic, magic;
uid_t root, mappedroot;
char *tmpbuf = NULL;
struct vfs_cap_data *cap;
- struct vfs_ns_cap_data *nscap;
+ struct vfs_ns_cap_data *nscap = NULL;
struct dentry *dentry;
struct user_namespace *fs_ns;
@@ -396,46 +397,61 @@ int cap_inode_getsecurity(struct inode *inode, const char *name, void **buffer,
fs_ns = inode->i_sb->s_user_ns;
cap = (struct vfs_cap_data *) tmpbuf;
if (is_v2header((size_t) ret, cap)) {
- /* If this is sizeof(vfs_cap_data) then we're ok with the
- * on-disk value, so return that. */
- if (alloc)
- *buffer = tmpbuf;
- else
- kfree(tmpbuf);
- return ret;
- } else if (!is_v3header((size_t) ret, cap)) {
- kfree(tmpbuf);
- return -EINVAL;
+ root = 0;
+ } else if (is_v3header((size_t) ret, cap)) {
+ nscap = (struct vfs_ns_cap_data *) tmpbuf;
+ root = le32_to_cpu(nscap->rootid);
+ } else {
+ size = -EINVAL;
+ goto out_free;
}
- nscap = (struct vfs_ns_cap_data *) tmpbuf;
- root = le32_to_cpu(nscap->rootid);
kroot = make_kuid(fs_ns, root);
/* If the root kuid maps to a valid uid in current ns, then return
* this as a nscap. */
mappedroot = from_kuid(current_user_ns(), kroot);
if (mappedroot != (uid_t)-1 && mappedroot != (uid_t)0) {
+ size = sizeof(struct vfs_ns_cap_data);
if (alloc) {
- *buffer = tmpbuf;
+ if (!nscap) {
+ /* v2 -> v3 conversion */
+ nscap = kzalloc(size, GFP_ATOMIC);
+ if (!nscap) {
+ size = -ENOMEM;
+ goto out_free;
+ }
+ nsmagic = VFS_CAP_REVISION_3;
+ magic = le32_to_cpu(cap->magic_etc);
+ if (magic & VFS_CAP_FLAGS_EFFECTIVE)
+ nsmagic |= VFS_CAP_FLAGS_EFFECTIVE;
+ memcpy(&nscap->data, &cap->data, sizeof(__le32) * 2 * VFS_CAP_U32);
+ nscap->magic_etc = cpu_to_le32(nsmagic);
+ } else {
+ /* use allocated v3 buffer */
+ tmpbuf = NULL;
+ }
nscap->rootid = cpu_to_le32(mappedroot);
- } else
- kfree(tmpbuf);
- return size;
+ *buffer = nscap;
+ }
+ goto out_free;
}
if (!rootid_owns_currentns(kroot)) {
- kfree(tmpbuf);
- return -EOPNOTSUPP;
+ size = -EOVERFLOW;
+ goto out_free;
}
/* This comes from a parent namespace. Return as a v2 capability */
size = sizeof(struct vfs_cap_data);
if (alloc) {
- *buffer = kmalloc(size, GFP_ATOMIC);
- if (*buffer) {
- struct vfs_cap_data *cap = *buffer;
- __le32 nsmagic, magic;
+ if (nscap) {
+ /* v3 -> v2 conversion */
+ cap = kzalloc(size, GFP_ATOMIC);
+ if (!cap) {
+ size = -ENOMEM;
+ goto out_free;
+ }
magic = VFS_CAP_REVISION_2;
nsmagic = le32_to_cpu(nscap->magic_etc);
if (nsmagic & VFS_CAP_FLAGS_EFFECTIVE)
@@ -443,9 +459,12 @@ int cap_inode_getsecurity(struct inode *inode, const char *name, void **buffer,
memcpy(&cap->data, &nscap->data, sizeof(__le32) * 2 * VFS_CAP_U32);
cap->magic_etc = cpu_to_le32(magic);
} else {
- size = -ENOMEM;
+ /* use unconverted v2 */
+ tmpbuf = NULL;
}
+ *buffer = cap;
}
+out_free:
kfree(tmpbuf);
return size;
}