From 512ecf84714aa7f906807c5149cd4776d157d7ab Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Thu, 25 Jul 2013 11:49:11 +0200 Subject: isofs: Refuse RW mount of the filesystem instead of making it RO commit 17b7f7cf58926844e1dd40f5eb5348d481deca6a upstream. Refuse RW mount of isofs filesystem. So far we just silently changed it to RO mount but when the media is writeable, block layer won't notice this change and thus will think device is used RW and will block eject button of the drive. That is unexpected by users because for non-writeable media eject button works just fine. Userspace mount(8) command handles this just fine and retries mounting with MS_RDONLY set so userspace shouldn't see any regression. Plus any tool mounting isofs is likely confronted with the case of read-only media where block layer already refuses to mount the filesystem without MS_RDONLY set so our behavior shouldn't be anything new for it. Reported-by: Hui Wang Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman --- fs/isofs/inode.c | 16 +++++----------- 1 file changed, 5 insertions(+), 11 deletions(-) (limited to 'fs') diff --git a/fs/isofs/inode.c b/fs/isofs/inode.c index 29037c365ba4..e92a342f14e7 100644 --- a/fs/isofs/inode.c +++ b/fs/isofs/inode.c @@ -119,8 +119,8 @@ static void destroy_inodecache(void) static int isofs_remount(struct super_block *sb, int *flags, char *data) { - /* we probably want a lot more here */ - *flags |= MS_RDONLY; + if (!(*flags & MS_RDONLY)) + return -EROFS; return 0; } @@ -769,15 +769,6 @@ root_found: */ s->s_maxbytes = 0x80000000000LL; - /* - * The CDROM is read-only, has no nodes (devices) on it, and since - * all of the files appear to be owned by root, we really do not want - * to allow suid. (suid or devices will not show up unless we have - * Rock Ridge extensions) - */ - - s->s_flags |= MS_RDONLY /* | MS_NODEV | MS_NOSUID */; - /* Set this for reference. Its not currently used except on write which we don't have .. */ @@ -1536,6 +1527,9 @@ struct inode *isofs_iget(struct super_block *sb, static struct dentry *isofs_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data) { + /* We don't support read-write mounts */ + if (!(flags & MS_RDONLY)) + return ERR_PTR(-EACCES); return mount_bdev(fs_type, flags, dev_name, data, isofs_fill_super); } -- cgit v1.2.3