From 5132861a7a44498ebb18357473f8b8d4cdc70e9f Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Thu, 22 May 2008 09:33:34 -0400 Subject: [PATCH] disable most mode changes on non-unix/non-cifsacl mounts CIFS currently allows you to change the mode of an inode on a share that doesn't have unix extensions enabled, and isn't using cifsacl. The inode in this case *only* has its mode changed in memory on the client. This is problematic since it can change any time the inode is purged from the cache. This patch makes cifs_setattr silently ignore most mode changes when unix extensions and cifsacl support are not enabled, and when the share is not mounted with the "dynperm" option. The exceptions are: When a mode change would remove all write access to an inode we turn on the ATTR_READONLY bit on the server and remove all write bits from the inode's mode in memory. When a mode change would add a write bit to an inode that previously had them all turned off, it turns off the ATTR_READONLY bit on the server, and resets the mode back to what it would normally be (generally, the file_mode or dir_mode of the share). Signed-off-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/inode.c | 38 ++++++++++++++++++++++++++------------ 1 file changed, 26 insertions(+), 12 deletions(-) diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c index fe752fdb26c3..722be543ceec 100644 --- a/fs/cifs/inode.c +++ b/fs/cifs/inode.c @@ -1575,7 +1575,7 @@ int cifs_setattr(struct dentry *direntry, struct iattr *attrs) attrs->ia_valid &= ~ATTR_MODE; if (attrs->ia_valid & ATTR_MODE) { - cFYI(1, ("Mode changed to 0x%x", attrs->ia_mode)); + cFYI(1, ("Mode changed to 0%o", attrs->ia_mode)); mode = attrs->ia_mode; } @@ -1590,18 +1590,18 @@ int cifs_setattr(struct dentry *direntry, struct iattr *attrs) #ifdef CONFIG_CIFS_EXPERIMENTAL if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) rc = mode_to_acl(inode, full_path, mode); - else if ((mode & S_IWUGO) == 0) { -#else - if ((mode & S_IWUGO) == 0) { + else #endif - /* not writeable */ - if ((cifsInode->cifsAttrs & ATTR_READONLY) == 0) { - set_dosattr = true; - time_buf.Attributes = - cpu_to_le32(cifsInode->cifsAttrs | - ATTR_READONLY); - } - } else if (cifsInode->cifsAttrs & ATTR_READONLY) { + if (((mode & S_IWUGO) == 0) && + (cifsInode->cifsAttrs & ATTR_READONLY) == 0) { + set_dosattr = true; + time_buf.Attributes = cpu_to_le32(cifsInode->cifsAttrs | + ATTR_READONLY); + /* fix up mode if we're not using dynperm */ + if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM) == 0) + attrs->ia_mode = inode->i_mode & ~S_IWUGO; + } else if ((mode & S_IWUGO) && + (cifsInode->cifsAttrs & ATTR_READONLY)) { /* If file is readonly on server, we would not be able to write to it - so if any write bit is enabled for user or group or other we @@ -1612,6 +1612,20 @@ int cifs_setattr(struct dentry *direntry, struct iattr *attrs) /* Windows ignores set to zero */ if (time_buf.Attributes == 0) time_buf.Attributes |= cpu_to_le32(ATTR_NORMAL); + + /* reset local inode permissions to normal */ + if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM)) { + attrs->ia_mode &= ~(S_IALLUGO); + if (S_ISDIR(inode->i_mode)) + attrs->ia_mode |= + cifs_sb->mnt_dir_mode; + else + attrs->ia_mode |= + cifs_sb->mnt_file_mode; + } + } else if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM)) { + /* ignore mode change - ATTR_READONLY hasn't changed */ + attrs->ia_valid &= ~ATTR_MODE; } } -- 2.20.1