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| author | Miklos Szeredi <mszeredi@redhat.com> | 2016-07-04 16:49:48 +0200 |
|---|---|---|
| committer | Sasha Levin <alexander.levin@verizon.com> | 2016-08-07 21:44:50 -0400 |
| commit | d4e1ac55843e799890318798794d7e6b48a68d4c (patch) | |
| tree | a6327728a903514f14f1b4ff3bcced135482e34c /fs | |
| parent | 69fb704cac4d3eb59b407f8cc8fa366c44e71318 (diff) | |
| download | lwn-d4e1ac55843e799890318798794d7e6b48a68d4c.tar.gz lwn-d4e1ac55843e799890318798794d7e6b48a68d4c.zip | |
ovl: handle ATTR_KILL*
[ Upstream commit b99c2d913810e56682a538c9f2394d76fca808f8 ]
Before 4bacc9c9234c ("overlayfs: Make f_path...") file->f_path pointed to
the underlying file, hence suid/sgid removal on write worked fine.
After that patch file->f_path pointed to the overlay file, and the file
mode bits weren't copied to overlay_inode->i_mode. So the suid/sgid
removal simply stopped working.
The fix is to copy the mode bits, but then ovl_setattr() needs to clear
ATTR_MODE to avoid the BUG() in notify_change(). So do this first, then in
the next patch copy the mode.
Reported-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 4bacc9c9234c ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay")
Cc: <stable@vger.kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/overlayfs/inode.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index e696ba32a2b5..7b0f4e39768f 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -54,6 +54,10 @@ int ovl_setattr(struct dentry *dentry, struct iattr *attr) upperdentry = ovl_dentry_upper(dentry); mutex_lock(&upperdentry->d_inode->i_mutex); + + if (attr->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID)) + attr->ia_valid &= ~ATTR_MODE; + err = notify_change(upperdentry, attr, NULL); if (!err) ovl_copyattr(upperdentry->d_inode, dentry->d_inode); |