Commit e4e5d3fc authored by Herbert Poetzl's avatar Herbert Poetzl Committed by Linus Torvalds

[PATCH] cleanup in proc_check_chroot()

proc_check_chroot() does the check in a very unintuitive way (keeping a
copy of the argument, then modifying the argument), and has uncommented
sideeffects.
Signed-off-by: default avatarHerbert Poetzl <herbert@13thfloor.at>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 158d9ebd
......@@ -534,12 +534,15 @@ static int proc_oom_score(struct task_struct *task, char *buffer)
/* If the process being read is separated by chroot from the reading process,
* don't let the reader access the threads.
*
* note: this does dput(root) and mntput(vfsmnt) on exit.
*/
static int proc_check_chroot(struct dentry *root, struct vfsmount *vfsmnt)
{
struct dentry *de, *base;
struct vfsmount *our_vfsmnt, *mnt;
int res = 0;
read_lock(&current->fs->lock);
our_vfsmnt = mntget(current->fs->rootmnt);
base = dget(current->fs->root);
......@@ -549,11 +552,11 @@ static int proc_check_chroot(struct dentry *root, struct vfsmount *vfsmnt)
de = root;
mnt = vfsmnt;
while (vfsmnt != our_vfsmnt) {
if (vfsmnt == vfsmnt->mnt_parent)
while (mnt != our_vfsmnt) {
if (mnt == mnt->mnt_parent)
goto out;
de = vfsmnt->mnt_mountpoint;
vfsmnt = vfsmnt->mnt_parent;
de = mnt->mnt_mountpoint;
mnt = mnt->mnt_parent;
}
if (!is_subdir(de, base))
......@@ -564,7 +567,7 @@ static int proc_check_chroot(struct dentry *root, struct vfsmount *vfsmnt)
dput(base);
mntput(our_vfsmnt);
dput(root);
mntput(mnt);
mntput(vfsmnt);
return res;
out:
spin_unlock(&vfsmount_lock);
......
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