diff options
Diffstat (limited to 'fs/namei.c')
| -rw-r--r-- | fs/namei.c | 35 |
1 files changed, 24 insertions, 11 deletions
diff --git a/fs/namei.c b/fs/namei.c index c5b2a25be7..1e05a0f3f0 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2422,6 +2422,14 @@ static const char *path_init(struct nameidata *nd, unsigned flags) if (!f.file) return ERR_PTR(-EBADF); + if (flags & LOOKUP_LINKAT_EMPTY) { + if (f.file->f_cred != current_cred() && + !ns_capable(f.file->f_cred->user_ns, CAP_DAC_READ_SEARCH)) { + fdput(f); + return ERR_PTR(-ENOENT); + } + } + dentry = f.file->f_path.dentry; if (*s && unlikely(!d_can_lookup(dentry))) { @@ -3564,8 +3572,12 @@ static const char *open_last_lookups(struct nameidata *nd, else inode_lock_shared(dir->d_inode); dentry = lookup_open(nd, file, op, got_write); - if (!IS_ERR(dentry) && (file->f_mode & FMODE_CREATED)) - fsnotify_create(dir->d_inode, dentry); + if (!IS_ERR(dentry)) { + if (file->f_mode & FMODE_CREATED) + fsnotify_create(dir->d_inode, dentry); + if (file->f_mode & FMODE_OPENED) + fsnotify_open(file); + } if (open_flag & O_CREAT) inode_unlock(dir->d_inode); else @@ -3668,9 +3680,9 @@ static int do_open(struct nameidata *nd, * On non-idmapped mounts or if permission checking is to be performed on the * raw inode simply pass @nop_mnt_idmap. */ -static int vfs_tmpfile(struct mnt_idmap *idmap, - const struct path *parentpath, - struct file *file, umode_t mode) +int vfs_tmpfile(struct mnt_idmap *idmap, + const struct path *parentpath, + struct file *file, umode_t mode) { struct dentry *child; struct inode *dir = d_inode(parentpath->dentry); @@ -3692,6 +3704,8 @@ static int vfs_tmpfile(struct mnt_idmap *idmap, mode = vfs_prepare_mode(idmap, dir, mode, mode, mode); error = dir->i_op->tmpfile(idmap, dir, file, mode); dput(child); + if (file->f_mode & FMODE_OPENED) + fsnotify_open(file); if (error) return error; /* Don't check for other permissions, the inode was just created */ @@ -4641,14 +4655,13 @@ int do_linkat(int olddfd, struct filename *old, int newdfd, goto out_putnames; } /* - * To use null names we require CAP_DAC_READ_SEARCH + * To use null names we require CAP_DAC_READ_SEARCH or + * that the open-time creds of the dfd matches current. * This ensures that not everyone will be able to create - * handlink using the passed filedescriptor. + * a hardlink using the passed file descriptor. */ - if (flags & AT_EMPTY_PATH && !capable(CAP_DAC_READ_SEARCH)) { - error = -ENOENT; - goto out_putnames; - } + if (flags & AT_EMPTY_PATH) + how |= LOOKUP_LINKAT_EMPTY; if (flags & AT_SYMLINK_FOLLOW) how |= LOOKUP_FOLLOW; |