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Diffstat (limited to 'fs/namei.c')
-rw-r--r--fs/namei.c146
1 files changed, 68 insertions, 78 deletions
diff --git a/fs/namei.c b/fs/namei.c
index 4ea63ed5e791..09ce58e49e72 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -212,8 +212,7 @@ int generic_permission(struct inode *inode, int mask,
* Read/write DACs are always overridable.
* Executable DACs are overridable if at least one exec bit is set.
*/
- if (!(mask & MAY_EXEC) ||
- (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode))
+ if (!(mask & MAY_EXEC) || execute_ok(inode))
if (capable(CAP_DAC_OVERRIDE))
return 0;
@@ -249,23 +248,11 @@ int inode_permission(struct inode *inode, int mask)
}
/* Ordinary permission routines do not understand MAY_APPEND. */
- if (inode->i_op && inode->i_op->permission) {
+ if (inode->i_op && inode->i_op->permission)
retval = inode->i_op->permission(inode, mask);
- if (!retval) {
- /*
- * Exec permission on a regular file is denied if none
- * of the execute bits are set.
- *
- * This check should be done by the ->permission()
- * method.
- */
- if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode) &&
- !(inode->i_mode & S_IXUGO))
- return -EACCES;
- }
- } else {
+ else
retval = generic_permission(inode, mask, NULL);
- }
+
if (retval)
return retval;
@@ -1106,6 +1093,15 @@ int path_lookup(const char *name, unsigned int flags,
return do_path_lookup(AT_FDCWD, name, flags, nd);
}
+int kern_path(const char *name, unsigned int flags, struct path *path)
+{
+ struct nameidata nd;
+ int res = do_path_lookup(AT_FDCWD, name, flags, &nd);
+ if (!res)
+ *path = nd.path;
+ return res;
+}
+
/**
* vfs_path_lookup - lookup a file path relative to a dentry-vfsmount pair
* @dentry: pointer to dentry of the base directory
@@ -1138,9 +1134,16 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt,
}
-static int __path_lookup_intent_open(int dfd, const char *name,
- unsigned int lookup_flags, struct nameidata *nd,
- int open_flags, int create_mode)
+/**
+ * path_lookup_open - lookup a file path with open intent
+ * @dfd: the directory to use as base, or AT_FDCWD
+ * @name: pointer to file name
+ * @lookup_flags: lookup intent flags
+ * @nd: pointer to nameidata
+ * @open_flags: open intent flags
+ */
+int path_lookup_open(int dfd, const char *name, unsigned int lookup_flags,
+ struct nameidata *nd, int open_flags)
{
struct file *filp = get_empty_filp();
int err;
@@ -1149,7 +1152,7 @@ static int __path_lookup_intent_open(int dfd, const char *name,
return -ENFILE;
nd->intent.open.file = filp;
nd->intent.open.flags = open_flags;
- nd->intent.open.create_mode = create_mode;
+ nd->intent.open.create_mode = 0;
err = do_path_lookup(dfd, name, lookup_flags|LOOKUP_OPEN, nd);
if (IS_ERR(nd->intent.open.file)) {
if (err == 0) {
@@ -1161,38 +1164,6 @@ static int __path_lookup_intent_open(int dfd, const char *name,
return err;
}
-/**
- * path_lookup_open - lookup a file path with open intent
- * @dfd: the directory to use as base, or AT_FDCWD
- * @name: pointer to file name
- * @lookup_flags: lookup intent flags
- * @nd: pointer to nameidata
- * @open_flags: open intent flags
- */
-int path_lookup_open(int dfd, const char *name, unsigned int lookup_flags,
- struct nameidata *nd, int open_flags)
-{
- return __path_lookup_intent_open(dfd, name, lookup_flags, nd,
- open_flags, 0);
-}
-
-/**
- * path_lookup_create - lookup a file path with open + create intent
- * @dfd: the directory to use as base, or AT_FDCWD
- * @name: pointer to file name
- * @lookup_flags: lookup intent flags
- * @nd: pointer to nameidata
- * @open_flags: open intent flags
- * @create_mode: create intent flags
- */
-static int path_lookup_create(int dfd, const char *name,
- unsigned int lookup_flags, struct nameidata *nd,
- int open_flags, int create_mode)
-{
- return __path_lookup_intent_open(dfd, name, lookup_flags|LOOKUP_CREATE,
- nd, open_flags, create_mode);
-}
-
static struct dentry *__lookup_hash(struct qstr *name,
struct dentry *base, struct nameidata *nd)
{
@@ -1470,20 +1441,18 @@ struct dentry *lock_rename(struct dentry *p1, struct dentry *p2)
mutex_lock(&p1->d_inode->i_sb->s_vfs_rename_mutex);
- for (p = p1; p->d_parent != p; p = p->d_parent) {
- if (p->d_parent == p2) {
- mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_PARENT);
- mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_CHILD);
- return p;
- }
+ p = d_ancestor(p2, p1);
+ if (p) {
+ mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_PARENT);
+ mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_CHILD);
+ return p;
}
- for (p = p2; p->d_parent != p; p = p->d_parent) {
- if (p->d_parent == p1) {
- mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT);
- mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_CHILD);
- return p;
- }
+ p = d_ancestor(p1, p2);
+ if (p) {
+ mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT);
+ mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_CHILD);
+ return p;
}
mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT);
@@ -1702,8 +1671,7 @@ struct file *do_filp_open(int dfd, const char *pathname,
/*
* Create - we need to know the parent.
*/
- error = path_lookup_create(dfd, pathname, LOOKUP_PARENT,
- &nd, flag, mode);
+ error = do_path_lookup(dfd, pathname, LOOKUP_PARENT, &nd);
if (error)
return ERR_PTR(error);
@@ -1714,10 +1682,20 @@ struct file *do_filp_open(int dfd, const char *pathname,
*/
error = -EISDIR;
if (nd.last_type != LAST_NORM || nd.last.name[nd.last.len])
- goto exit;
+ goto exit_parent;
+ error = -ENFILE;
+ filp = get_empty_filp();
+ if (filp == NULL)
+ goto exit_parent;
+ nd.intent.open.file = filp;
+ nd.intent.open.flags = flag;
+ nd.intent.open.create_mode = mode;
dir = nd.path.dentry;
nd.flags &= ~LOOKUP_PARENT;
+ nd.flags |= LOOKUP_CREATE | LOOKUP_OPEN;
+ if (flag & O_EXCL)
+ nd.flags |= LOOKUP_EXCL;
mutex_lock(&dir->d_inode->i_mutex);
path.dentry = lookup_hash(&nd);
path.mnt = nd.path.mnt;
@@ -1822,6 +1800,7 @@ exit_dput:
exit:
if (!IS_ERR(nd.intent.open.file))
release_open_intent(&nd);
+exit_parent:
path_put(&nd.path);
return ERR_PTR(error);
@@ -1914,7 +1893,7 @@ struct dentry *lookup_create(struct nameidata *nd, int is_dir)
if (nd->last_type != LAST_NORM)
goto fail;
nd->flags &= ~LOOKUP_PARENT;
- nd->flags |= LOOKUP_CREATE;
+ nd->flags |= LOOKUP_CREATE | LOOKUP_EXCL;
nd->intent.open.flags = O_EXCL;
/*
@@ -2178,16 +2157,19 @@ static long do_rmdir(int dfd, const char __user *pathname)
return error;
switch(nd.last_type) {
- case LAST_DOTDOT:
- error = -ENOTEMPTY;
- goto exit1;
- case LAST_DOT:
- error = -EINVAL;
- goto exit1;
- case LAST_ROOT:
- error = -EBUSY;
- goto exit1;
+ case LAST_DOTDOT:
+ error = -ENOTEMPTY;
+ goto exit1;
+ case LAST_DOT:
+ error = -EINVAL;
+ goto exit1;
+ case LAST_ROOT:
+ error = -EBUSY;
+ goto exit1;
}
+
+ nd.flags &= ~LOOKUP_PARENT;
+
mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
dentry = lookup_hash(&nd);
error = PTR_ERR(dentry);
@@ -2265,6 +2247,9 @@ static long do_unlinkat(int dfd, const char __user *pathname)
error = -EISDIR;
if (nd.last_type != LAST_NORM)
goto exit1;
+
+ nd.flags &= ~LOOKUP_PARENT;
+
mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
dentry = lookup_hash(&nd);
error = PTR_ERR(dentry);
@@ -2654,6 +2639,10 @@ asmlinkage long sys_renameat(int olddfd, const char __user *oldname,
if (newnd.last_type != LAST_NORM)
goto exit2;
+ oldnd.flags &= ~LOOKUP_PARENT;
+ newnd.flags &= ~LOOKUP_PARENT;
+ newnd.flags |= LOOKUP_RENAME_TARGET;
+
trap = lock_rename(new_dir, old_dir);
old_dentry = lookup_hash(&oldnd);
@@ -2855,6 +2844,7 @@ EXPORT_SYMBOL(__page_symlink);
EXPORT_SYMBOL(page_symlink);
EXPORT_SYMBOL(page_symlink_inode_operations);
EXPORT_SYMBOL(path_lookup);
+EXPORT_SYMBOL(kern_path);
EXPORT_SYMBOL(vfs_path_lookup);
EXPORT_SYMBOL(inode_permission);
EXPORT_SYMBOL(vfs_permission);
generated by cgit 1.2.3-korg (git 2.39.0) at 2024-05-07 23:57:17 +0000