diff options
| author | Miklos Szeredi <mszeredi@redhat.com> | 2016-12-06 16:18:45 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2017-02-23 03:54:43 +0000 |
| commit | a4ab1eeb4f60563209664142185a4969c703f02d (patch) | |
| tree | cc1f1d6c2dbdce6d48d40081caa2e0016c7e3d31 /fs/fuse/dir.c | |
| parent | dd613d3308c5d7223746b955317fd5f825074419 (diff) | |
fuse: fix clearing suid, sgid for chown()
commit c01638f5d919728f565bf8b5e0a6a159642df0d9 upstream.
Basically, the pjdfstests set the ownership of a file to 06555, and then
chowns it (as root) to a new uid/gid. Prior to commit a09f99eddef4 ("fuse:
fix killing s[ug]id in setattr"), fuse would send down a setattr with both
the uid/gid change and a new mode. Now, it just sends down the uid/gid
change.
Technically this is NOTABUG, since POSIX doesn't _require_ that we clear
these bits for a privileged process, but Linux (wisely) has done that and I
think we don't want to change that behavior here.
This is caused by the use of should_remove_suid(), which will always return
0 when the process has CAP_FSETID.
In fact we really don't need to be calling should_remove_suid() at all,
since we've already been indicated that we should remove the suid, we just
don't want to use a (very) stale mode for that.
This patch should fix the above as well as simplify the logic.
Reported-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: a09f99eddef4 ("fuse: fix killing s[ug]id in setattr")
Reviewed-by: Jeff Layton <jlayton@redhat.com>
[bwh: Backported to 3.16: adjust context, indentation]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'fs/fuse/dir.c')
| -rw-r--r-- | fs/fuse/dir.c | 7 |
1 files changed, 2 insertions, 5 deletions
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index 2ef8defac554..a5c32420bfc8 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -1829,8 +1829,6 @@ static int fuse_setattr(struct dentry *entry, struct iattr *attr) return -EACCES; if (attr->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID)) { - int kill; - attr->ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE); /* @@ -1842,12 +1840,11 @@ static int fuse_setattr(struct dentry *entry, struct iattr *attr) return ret; attr->ia_mode = inode->i_mode; - kill = should_remove_suid(entry); - if (kill & ATTR_KILL_SUID) { + if (inode->i_mode & S_ISUID) { attr->ia_valid |= ATTR_MODE; attr->ia_mode &= ~S_ISUID; } - if (kill & ATTR_KILL_SGID) { + if ((inode->i_mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { attr->ia_valid |= ATTR_MODE; attr->ia_mode &= ~S_ISGID; } |