Commit fe542cf5 authored by Tetsuo Handa's avatar Tetsuo Handa Committed by James Morris

LSM: Move security_path_chmod()/security_path_chown() to after mutex_lock().

We should call security_path_chmod()/security_path_chown() after mutex_lock()
in order to avoid races.
Signed-off-by: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: default avatarJohn Johansen <john.johansen@canonical.com>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
parent 85c3b529
......@@ -619,17 +619,17 @@ SYSCALL_DEFINE2(fchmod, unsigned int, fd, mode_t, mode)
err = mnt_want_write_file(file);
if (err)
goto out_putf;
mutex_lock(&inode->i_mutex);
err = security_path_chmod(dentry, file->f_vfsmnt, mode);
if (err)
goto out_drop_write;
mutex_lock(&inode->i_mutex);
goto out_unlock;
if (mode == (mode_t) -1)
mode = inode->i_mode;
newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
err = notify_change(dentry, &newattrs);
out_unlock:
mutex_unlock(&inode->i_mutex);
out_drop_write:
mnt_drop_write(file->f_path.mnt);
out_putf:
fput(file);
......@@ -652,17 +652,17 @@ SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename, mode_t, mode)
error = mnt_want_write(path.mnt);
if (error)
goto dput_and_out;
mutex_lock(&inode->i_mutex);
error = security_path_chmod(path.dentry, path.mnt, mode);
if (error)
goto out_drop_write;
mutex_lock(&inode->i_mutex);
goto out_unlock;
if (mode == (mode_t) -1)
mode = inode->i_mode;
newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
error = notify_change(path.dentry, &newattrs);
out_unlock:
mutex_unlock(&inode->i_mutex);
out_drop_write:
mnt_drop_write(path.mnt);
dput_and_out:
path_put(&path);
......@@ -675,9 +675,9 @@ SYSCALL_DEFINE2(chmod, const char __user *, filename, mode_t, mode)
return sys_fchmodat(AT_FDCWD, filename, mode);
}
static int chown_common(struct dentry * dentry, uid_t user, gid_t group)
static int chown_common(struct path *path, uid_t user, gid_t group)
{
struct inode *inode = dentry->d_inode;
struct inode *inode = path->dentry->d_inode;
int error;
struct iattr newattrs;
......@@ -694,7 +694,9 @@ static int chown_common(struct dentry * dentry, uid_t user, gid_t group)
newattrs.ia_valid |=
ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV;
mutex_lock(&inode->i_mutex);
error = notify_change(dentry, &newattrs);
error = security_path_chown(path, user, group);
if (!error)
error = notify_change(path->dentry, &newattrs);
mutex_unlock(&inode->i_mutex);
return error;
......@@ -711,9 +713,7 @@ SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group)
error = mnt_want_write(path.mnt);
if (error)
goto out_release;
error = security_path_chown(&path, user, group);
if (!error)
error = chown_common(path.dentry, user, group);
error = chown_common(&path, user, group);
mnt_drop_write(path.mnt);
out_release:
path_put(&path);
......@@ -738,9 +738,7 @@ SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user,
error = mnt_want_write(path.mnt);
if (error)
goto out_release;
error = security_path_chown(&path, user, group);
if (!error)
error = chown_common(path.dentry, user, group);
error = chown_common(&path, user, group);
mnt_drop_write(path.mnt);
out_release:
path_put(&path);
......@@ -759,9 +757,7 @@ SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group
error = mnt_want_write(path.mnt);
if (error)
goto out_release;
error = security_path_chown(&path, user, group);
if (!error)
error = chown_common(path.dentry, user, group);
error = chown_common(&path, user, group);
mnt_drop_write(path.mnt);
out_release:
path_put(&path);
......@@ -784,9 +780,7 @@ SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group)
goto out_fput;
dentry = file->f_path.dentry;
audit_inode(NULL, dentry);
error = security_path_chown(&file->f_path, user, group);
if (!error)
error = chown_common(dentry, user, group);
error = chown_common(&file->f_path, user, group);
mnt_drop_write(file->f_path.mnt);
out_fput:
fput(file);
......
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