From: Hugh Dickins <hugh@veritas.com>
After chdir (or chroot) to non-existent directory on 2.6.5-mm5, you can no
longer unmount filesystem holding working directory (or root).
---
25-akpm/fs/open.c | 14 ++++++++++----
1 files changed, 10 insertions(+), 4 deletions(-)
diff -puN fs/open.c~umount-after-bad-chdir fs/open.c
--- 25/fs/open.c~umount-after-bad-chdir 2004-04-14 11:19:46.961042360 -0700
+++ 25-akpm/fs/open.c 2004-04-14 11:19:46.966041600 -0700
@@ -517,13 +517,16 @@ asmlinkage long sys_chdir(const char __u
{
struct nameidata nd;
int error;
- struct vfsmount *old_mnt = mntget(current->fs->pwdmnt);
- struct dentry *old_dentry = dget(current->fs->pwd);
+ struct vfsmount *old_mnt;
+ struct dentry *old_dentry;
error = __user_walk(filename, LOOKUP_FOLLOW|LOOKUP_DIRECTORY, &nd);
if (error)
goto out;
+ old_mnt = mntget(current->fs->pwdmnt);
+ old_dentry = dget(current->fs->pwd);
+
error = permission(nd.dentry->d_inode,MAY_EXEC,&nd);
if (error)
goto dput_and_out;
@@ -590,13 +593,16 @@ asmlinkage long sys_chroot(const char __
{
struct nameidata nd;
int error;
- struct vfsmount *old_mnt = mntget(current->fs->rootmnt);
- struct dentry *old_dentry = dget(current->fs->root);
+ struct vfsmount *old_mnt;
+ struct dentry *old_dentry;
error = __user_walk(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY | LOOKUP_NOALT, &nd);
if (error)
goto out;
+ old_mnt = mntget(current->fs->pwdmnt);
+ old_dentry = dget(current->fs->pwd);
+
error = permission(nd.dentry->d_inode,MAY_EXEC,&nd);
if (error)
goto dput_and_out;
_