path: root/mm/filemap.c
diff options
authorAl Viro <>2011-06-03 18:24:58 -0400
committerAl Viro <>2011-06-03 18:24:58 -0400
commit9e1f1de02c2275d7172e18dc4e7c2065777611bf (patch)
tree15e9d202e64275cdbff6ed1d54804da5966d7d8d /mm/filemap.c
parent1fa7b6a29c61358cc2ca6f64cef4aa0e1a7ca74c (diff)
more conservative S_NOSEC handling
Caching "we have already removed suid/caps" was overenthusiastic as merged. On network filesystems we might have had suid/caps set on another client, silently picked by this client on revalidate, all of that *without* clearing the S_NOSEC flag. AFAICS, the only reasonably sane way to deal with that is * new superblock flag; unless set, S_NOSEC is not going to be set. * local block filesystems set it in their ->mount() (more accurately, mount_bdev() does, so does btrfs ->mount(), users of mount_bdev() other than local block ones clear it) * if any network filesystem (or a cluster one) wants to use S_NOSEC, it'll need to set MS_NOSEC in sb->s_flags *AND* take care to clear S_NOSEC when inode attribute changes are picked from other clients. It's not an earth-shattering hole (anybody that can set suid on another client will almost certainly be able to write to the file before doing that anyway), but it's a bug that needs fixing. Signed-off-by: Al Viro <>
Diffstat (limited to 'mm/filemap.c')
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/filemap.c b/mm/filemap.c
index d7b10578a64b..a8251a8d3457 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2000,7 +2000,7 @@ int file_remove_suid(struct file *file)
error = security_inode_killpriv(dentry);
if (!error && killsuid)
error = __remove_suid(dentry, killsuid);
- if (!error)
+ if (!error && (inode->i_sb->s_flags & MS_NOSEC))
inode->i_flags |= S_NOSEC;
return error;