1 files changed, 125 insertions, 115 deletions

diff --git a/fs/namei.c b/fs/namei.c
index cafa365eeb70..186bd2464fd5 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -39,6 +39,7 @@
 #include <linux/bitops.h>
 #include <linux/init_task.h>
 #include <linux/uaccess.h>
+#include <linux/build_bug.h>
 
 #include "internal.h"
 #include "mount.h"
@@ -130,6 +131,7 @@ getname_flags(const char __user *filename, int flags, int *empty)
 	struct filename *result;
 	char *kname;
 	int len;
+	BUILD_BUG_ON(offsetof(struct filename, iname) % sizeof(long) != 0);
 
 	result = audit_reusename(filename);
 	if (result)
@@ -222,9 +224,10 @@ getname_kernel(const char * filename)
 	if (len <= EMBEDDED_NAME_MAX) {
 		result->name = (char *)result->iname;
 	} else if (len <= PATH_MAX) {
+		const size_t size = offsetof(struct filename, iname[1]);
 		struct filename *tmp;
 
-		tmp = kmalloc(sizeof(*tmp), GFP_KERNEL);
+		tmp = kmalloc(size, GFP_KERNEL);
 		if (unlikely(!tmp)) {
 			__putname(result);
 			return ERR_PTR(-ENOMEM);
@@ -927,7 +930,8 @@ static inline int may_follow_link(struct nameidata *nd)
 	if (nd->flags & LOOKUP_RCU)
 		return -ECHILD;
 
-	audit_log_link_denied("follow_link", &nd->stack[0].link);
+	audit_inode(nd->name, nd->stack[0].link.dentry, 0);
+	audit_log_link_denied("follow_link");
 	return -EACCES;
 }
 
@@ -993,7 +997,7 @@ static int may_linkat(struct path *link)
 	if (safe_hardlink_source(inode) || inode_owner_or_capable(inode))
 		return 0;
 
-	audit_log_link_denied("linkat", link);
+	audit_log_link_denied("linkat");
 	return -EPERM;
 }
 
@@ -1474,43 +1478,36 @@ static struct dentry *lookup_dcache(const struct qstr *name,
 }
 
 /*
- * Call i_op->lookup on the dentry.  The dentry must be negative and
- * unhashed.
- *
- * dir->d_inode->i_mutex must be held
+ * Parent directory has inode locked exclusive.  This is one
+ * and only case when ->lookup() gets called on non in-lookup
+ * dentries - as the matter of fact, this only gets called
+ * when directory is guaranteed to have no in-lookup children
+ * at all.
  */
-static struct dentry *lookup_real(struct inode *dir, struct dentry *dentry,
-				  unsigned int flags)
-{
-	struct dentry *old;
-
-	/* Don't create child dentry for a dead directory. */
-	if (unlikely(IS_DEADDIR(dir))) {
-		dput(dentry);
-		return ERR_PTR(-ENOENT);
-	}
-
-	old = dir->i_op->lookup(dir, dentry, flags);
-	if (unlikely(old)) {
-		dput(dentry);
-		dentry = old;
-	}
-	return dentry;
-}
-
 static struct dentry *__lookup_hash(const struct qstr *name,
 		struct dentry *base, unsigned int flags)
 {
 	struct dentry *dentry = lookup_dcache(name, base, flags);
+	struct dentry *old;
+	struct inode *dir = base->d_inode;
 
 	if (dentry)
 		return dentry;
 
+	/* Don't create child dentry for a dead directory. */
+	if (unlikely(IS_DEADDIR(dir)))
+		return ERR_PTR(-ENOENT);
+
 	dentry = d_alloc(base, name);
 	if (unlikely(!dentry))
 		return ERR_PTR(-ENOMEM);
 
-	return lookup_real(base->d_inode, dentry, flags);
+	old = dir->i_op->lookup(dir, dentry, flags);
+	if (unlikely(old)) {
+		dput(dentry);
+		dentry = old;
+	}
+	return dentry;
 }
 
 static int lookup_fast(struct nameidata *nd,
@@ -1601,22 +1598,21 @@ static int lookup_fast(struct nameidata *nd,
 }
 
 /* Fast lookup failed, do it the slow way */
-static struct dentry *lookup_slow(const struct qstr *name,
-				  struct dentry *dir,
-				  unsigned int flags)
+static struct dentry *__lookup_slow(const struct qstr *name,
+				    struct dentry *dir,
+				    unsigned int flags)
 {
-	struct dentry *dentry = ERR_PTR(-ENOENT), *old;
+	struct dentry *dentry, *old;
 	struct inode *inode = dir->d_inode;
 	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
 
-	inode_lock_shared(inode);
 	/* Don't go there if it's already dead */
 	if (unlikely(IS_DEADDIR(inode)))
-		goto out;
+		return ERR_PTR(-ENOENT);
 again:
 	dentry = d_alloc_parallel(dir, name, &wq);
 	if (IS_ERR(dentry))
-		goto out;
+		return dentry;
 	if (unlikely(!d_in_lookup(dentry))) {
 		if (!(flags & LOOKUP_NO_REVAL)) {
 			int error = d_revalidate(dentry, flags);
@@ -1638,11 +1634,21 @@ again:
 			dentry = old;
 		}
 	}
-out:
-	inode_unlock_shared(inode);
 	return dentry;
 }
 
+static struct dentry *lookup_slow(const struct qstr *name,
+				  struct dentry *dir,
+				  unsigned int flags)
+{
+	struct inode *inode = dir->d_inode;
+	struct dentry *res;
+	inode_lock_shared(inode);
+	res = __lookup_slow(name, dir, flags);
+	inode_unlock_shared(inode);
+	return res;
+}
+
 static inline int may_lookup(struct nameidata *nd)
 {
 	if (nd->flags & LOOKUP_RCU) {
@@ -2425,56 +2431,63 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt,
 }
 EXPORT_SYMBOL(vfs_path_lookup);
 
-/**
- * lookup_one_len - filesystem helper to lookup single pathname component
- * @name:	pathname component to lookup
- * @base:	base directory to lookup from
- * @len:	maximum length @len should be interpreted to
- *
- * Note that this routine is purely a helper for filesystem usage and should
- * not be called by generic code.
- *
- * The caller must hold base->i_mutex.
- */
-struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
+static int lookup_one_len_common(const char *name, struct dentry *base,
+				 int len, struct qstr *this)
 {
-	struct qstr this;
-	unsigned int c;
-	int err;
-
-	WARN_ON_ONCE(!inode_is_locked(base->d_inode));
-
-	this.name = name;
-	this.len = len;
-	this.hash = full_name_hash(base, name, len);
+	this->name = name;
+	this->len = len;
+	this->hash = full_name_hash(base, name, len);
 	if (!len)
-		return ERR_PTR(-EACCES);
+		return -EACCES;
 
 	if (unlikely(name[0] == '.')) {
 		if (len < 2 || (len == 2 && name[1] == '.'))
-			return ERR_PTR(-EACCES);
+			return -EACCES;
 	}
 
 	while (len--) {
-		c = *(const unsigned char *)name++;
+		unsigned int c = *(const unsigned char *)name++;
 		if (c == '/' || c == '\0')
-			return ERR_PTR(-EACCES);
+			return -EACCES;
 	}
 	/*
 	 * See if the low-level filesystem might want
 	 * to use its own hash..
 	 */
 	if (base->d_flags & DCACHE_OP_HASH) {
-		int err = base->d_op->d_hash(base, &this);
+		int err = base->d_op->d_hash(base, this);
 		if (err < 0)
-			return ERR_PTR(err);
+			return err;
 	}
 
-	err = inode_permission(base->d_inode, MAY_EXEC);
+	return inode_permission(base->d_inode, MAY_EXEC);
+}
+
+/**
+ * lookup_one_len - filesystem helper to lookup single pathname component
+ * @name:	pathname component to lookup
+ * @base:	base directory to lookup from
+ * @len:	maximum length @len should be interpreted to
+ *
+ * Note that this routine is purely a helper for filesystem usage and should
+ * not be called by generic code.
+ *
+ * The caller must hold base->i_mutex.
+ */
+struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
+{
+	struct dentry *dentry;
+	struct qstr this;
+	int err;
+
+	WARN_ON_ONCE(!inode_is_locked(base->d_inode));
+
+	err = lookup_one_len_common(name, base, len, &this);
 	if (err)
 		return ERR_PTR(err);
 
-	return __lookup_hash(&this, base, 0);
+	dentry = lookup_dcache(&this, base, 0);
+	return dentry ? dentry : __lookup_slow(&this, base, 0);
 }
 EXPORT_SYMBOL(lookup_one_len);
 
@@ -2494,37 +2507,10 @@ struct dentry *lookup_one_len_unlocked(const char *name,
 				       struct dentry *base, int len)
 {
 	struct qstr this;
-	unsigned int c;
 	int err;
 	struct dentry *ret;
 
-	this.name = name;
-	this.len = len;
-	this.hash = full_name_hash(base, name, len);
-	if (!len)
-		return ERR_PTR(-EACCES);
-
-	if (unlikely(name[0] == '.')) {
-		if (len < 2 || (len == 2 && name[1] == '.'))
-			return ERR_PTR(-EACCES);
-	}
-
-	while (len--) {
-		c = *(const unsigned char *)name++;
-		if (c == '/' || c == '\0')
-			return ERR_PTR(-EACCES);
-	}
-	/*
-	 * See if the low-level filesystem might want
-	 * to use its own hash..
-	 */
-	if (base->d_flags & DCACHE_OP_HASH) {
-		int err = base->d_op->d_hash(base, &this);
-		if (err < 0)
-			return ERR_PTR(err);
-	}
-
-	err = inode_permission(base->d_inode, MAY_EXEC);
+	err = lookup_one_len_common(name, base, len, &this);
 	if (err)
 		return ERR_PTR(err);
 
@@ -3381,9 +3367,7 @@ finish_open_created:
 		goto out;
 	*opened |= FILE_OPENED;
 opened:
-	error = open_check_o_direct(file);
-	if (!error)
-		error = ima_file_check(file, op->acc_mode, *opened);
+	error = ima_file_check(file, op->acc_mode, *opened);
 	if (!error && will_truncate)
 		error = handle_truncate(file);
 out:
@@ -3463,9 +3447,6 @@ static int do_tmpfile(struct nameidata *nd, unsigned flags,
 	error = finish_open(file, child, NULL, opened);
 	if (error)
 		goto out2;
-	error = open_check_o_direct(file);
-	if (error)
-		fput(file);
 out2:
 	mnt_drop_write(path.mnt);
 out:
@@ -3729,8 +3710,8 @@ static int may_mknod(umode_t mode)
 	}
 }
 
-SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, umode_t, mode,
-		unsigned, dev)
+long do_mknodat(int dfd, const char __user *filename, umode_t mode,
+		unsigned int dev)
 {
 	struct dentry *dentry;
 	struct path path;
@@ -3773,9 +3754,15 @@ out:
 	return error;
 }
 
+SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, umode_t, mode,
+		unsigned int, dev)
+{
+	return do_mknodat(dfd, filename, mode, dev);
+}
+
 SYSCALL_DEFINE3(mknod, const char __user *, filename, umode_t, mode, unsigned, dev)
 {
-	return sys_mknodat(AT_FDCWD, filename, mode, dev);
+	return do_mknodat(AT_FDCWD, filename, mode, dev);
 }
 
 int vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
@@ -3804,7 +3791,7 @@ int vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 }
 EXPORT_SYMBOL(vfs_mkdir);
 
-SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, umode_t, mode)
+long do_mkdirat(int dfd, const char __user *pathname, umode_t mode)
 {
 	struct dentry *dentry;
 	struct path path;
@@ -3829,9 +3816,14 @@ retry:
 	return error;
 }
 
+SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, umode_t, mode)
+{
+	return do_mkdirat(dfd, pathname, mode);
+}
+
 SYSCALL_DEFINE2(mkdir, const char __user *, pathname, umode_t, mode)
 {
-	return sys_mkdirat(AT_FDCWD, pathname, mode);
+	return do_mkdirat(AT_FDCWD, pathname, mode);
 }
 
 int vfs_rmdir(struct inode *dir, struct dentry *dentry)
@@ -3873,7 +3865,7 @@ out:
 }
 EXPORT_SYMBOL(vfs_rmdir);
 
-static long do_rmdir(int dfd, const char __user *pathname)
+long do_rmdir(int dfd, const char __user *pathname)
 {
 	int error = 0;
 	struct filename *name;
@@ -4109,8 +4101,8 @@ int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname)
 }
 EXPORT_SYMBOL(vfs_symlink);
 
-SYSCALL_DEFINE3(symlinkat, const char __user *, oldname,
-		int, newdfd, const char __user *, newname)
+long do_symlinkat(const char __user *oldname, int newdfd,
+		  const char __user *newname)
 {
 	int error;
 	struct filename *from;
@@ -4140,9 +4132,15 @@ out_putname:
 	return error;
 }
 
+SYSCALL_DEFINE3(symlinkat, const char __user *, oldname,
+		int, newdfd, const char __user *, newname)
+{
+	return do_symlinkat(oldname, newdfd, newname);
+}
+
 SYSCALL_DEFINE2(symlink, const char __user *, oldname, const char __user *, newname)
 {
-	return sys_symlinkat(oldname, AT_FDCWD, newname);
+	return do_symlinkat(oldname, AT_FDCWD, newname);
 }
 
 /**
@@ -4234,8 +4232,8 @@ EXPORT_SYMBOL(vfs_link);
  * with linux 2.0, and to avoid hard-linking to directories
  * and other special files.  --ADM
  */
-SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname,
-		int, newdfd, const char __user *, newname, int, flags)
+int do_linkat(int olddfd, const char __user *oldname, int newdfd,
+	      const char __user *newname, int flags)
 {
 	struct dentry *new_dentry;
 	struct path old_path, new_path;
@@ -4299,9 +4297,15 @@ out:
 	return error;
 }
 
+SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname,
+		int, newdfd, const char __user *, newname, int, flags)
+{
+	return do_linkat(olddfd, oldname, newdfd, newname, flags);
+}
+
 SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname)
 {
-	return sys_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0);
+	return do_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0);
 }
 
 /**
@@ -4479,8 +4483,8 @@ out:
 }
 EXPORT_SYMBOL(vfs_rename);
 
-SYSCALL_DEFINE5(renameat2, int, olddfd, const char __user *, oldname,
-		int, newdfd, const char __user *, newname, unsigned int, flags)
+static int do_renameat2(int olddfd, const char __user *oldname, int newdfd,
+			const char __user *newname, unsigned int flags)
 {
 	struct dentry *old_dentry, *new_dentry;
 	struct dentry *trap;
@@ -4622,15 +4626,21 @@ exit:
 	return error;
 }
 
+SYSCALL_DEFINE5(renameat2, int, olddfd, const char __user *, oldname,
+		int, newdfd, const char __user *, newname, unsigned int, flags)
+{
+	return do_renameat2(olddfd, oldname, newdfd, newname, flags);
+}
+
 SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname,
 		int, newdfd, const char __user *, newname)
 {
-	return sys_renameat2(olddfd, oldname, newdfd, newname, 0);
+	return do_renameat2(olddfd, oldname, newdfd, newname, 0);
 }
 
 SYSCALL_DEFINE2(rename, const char __user *, oldname, const char __user *, newname)
 {
-	return sys_renameat2(AT_FDCWD, oldname, AT_FDCWD, newname, 0);
+	return do_renameat2(AT_FDCWD, oldname, AT_FDCWD, newname, 0);
 }
 
 int vfs_whiteout(struct inode *dir, struct dentry *dentry)