From fe542cf59bf0b31afe72b9e9749c0f6645419fa0 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Sun, 22 Nov 2009 11:49:55 +0900 Subject: 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: Tetsuo Handa Acked-by: John Johansen Signed-off-by: James Morris --- fs/open.c | 36 +++++++++++++++--------------------- 1 file changed, 15 insertions(+), 21 deletions(-) (limited to 'fs/open.c') diff --git a/fs/open.c b/fs/open.c index 201041d..b4b31d2 100644 --- a/fs/open.c +++ b/fs/open.c @@ -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); -- cgit v1.1