[PATCH 7/7] unionfs: fix unionfs_create and unionfs_setattr to handle ATTR_KILL_S*ID

From: Jeff Layton
Date: Tue Sep 04 2007 - 10:39:43 EST


Don't allow either function to trip the BUG() in notify_change. For
unionfs_setattr, clear ATTR_MODE if the either ATTR_KILL_S*ID is set.

unionfs_create is setting the mode explicitly already. Don't set
ATTR_KILL_S*ID. Just fix up the mode to have the same effect. Also, move
locking the i_mutex to lower in the function. It's not needed until it
checks the i_size.

(Jeff Sipek indicated that he was planning to change some of this code,
so this patch may need changes if it goes in after his patchset)

Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/unionfs/inode.c | 10 ++++++----
1 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/fs/unionfs/inode.c b/fs/unionfs/inode.c
index 59bb418..f2e7f25 100644
--- a/fs/unionfs/inode.c
+++ b/fs/unionfs/inode.c
@@ -78,15 +78,14 @@ static int unionfs_create(struct inode *parent, struct dentry *dentry,
struct dentry *lower_dir_dentry;
struct iattr newattrs;

- mutex_lock(&wh_dentry->d_inode->i_mutex);
newattrs.ia_valid = ATTR_CTIME | ATTR_MODE | ATTR_ATIME
- | ATTR_MTIME | ATTR_UID | ATTR_GID | ATTR_FORCE
- | ATTR_KILL_SUID | ATTR_KILL_SGID;
+ | ATTR_MTIME | ATTR_UID | ATTR_GID | ATTR_FORCE;

- newattrs.ia_mode = mode & ~current->fs->umask;
+ newattrs.ia_mode = mode & ~(current->fs->umask|S_ISUID|S_ISGID);
newattrs.ia_uid = current->fsuid;
newattrs.ia_gid = current->fsgid;

+ mutex_lock(&wh_dentry->d_inode->i_mutex);
if (wh_dentry->d_inode->i_size != 0) {
newattrs.ia_valid |= ATTR_SIZE;
newattrs.ia_size = 0;
@@ -1032,6 +1031,9 @@ static int unionfs_setattr(struct dentry *dentry, struct iattr *ia)
bend = dbend(dentry);
inode = dentry->d_inode;

+ if (ia->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
+ ia->ia_valid &= ~ATTR_MODE;
+
for (bindex = bstart; (bindex <= bend) || (bindex == bstart);
bindex++) {
lower_dentry = unionfs_lower_dentry_idx(dentry, bindex);
--
1.5.2.1

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