The commit is pushed to "branch-rh7-3.10.0-229.7.2.vz7.9.x-ovz" and will appear
at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-229.7.2.vz7.9.20
------>
commit b51ecb573ac11fc5ed86c210c1731607199c9652
Author: Cyrill Gorcunov <[email protected]>
Date: Thu Jan 14 15:57:30 2016 +0400
ms/ovl: fix permission checking for setattr
This fixes CVE-2015-8660.
https://access.redhat.com/security/cve/cve-2015-8660
ms commit: acff81ec2c79492b180fade3c2894425cd35a545
From: Miklos Szeredi <[email protected]>
[Al Viro] The bug is in being too enthusiastic about optimizing ->setattr()
away - instead of "copy verbatim with metadata" + "chmod/chown/utimes"
(with the former being always safe and the latter failing in case of
insufficient permissions) it tries to combine these two. Note that copyup
itself will have to do ->setattr() anyway; _that_ is where the elevated
capabilities are right. Having these two ->setattr() (one to set verbatim
copy of metadata, another to do what overlayfs ->setattr() had been asked
to do in the first place) combined is where it breaks.
Signed-off-by: Miklos Szeredi <[email protected]>
Cc: <[email protected]>
Signed-off-by: Al Viro <[email protected]>
Signed-off-by: Cyrill Gorcunov <[email protected]>
---
fs/overlayfs/inode.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 9ad8de5..70db25a 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -49,13 +49,13 @@ int ovl_setattr(struct dentry *dentry, struct iattr *attr)
if (err)
goto out;
- upperdentry = ovl_dentry_upper(dentry);
- if (upperdentry) {
+ err = ovl_copy_up(dentry);
+ if (!err) {
+ upperdentry = ovl_dentry_upper(dentry);
+
mutex_lock(&upperdentry->d_inode->i_mutex);
err = notify_change(upperdentry, attr, NULL);
mutex_unlock(&upperdentry->d_inode->i_mutex);
- } else {
- err = ovl_copy_up_last(dentry, attr, false);
}
ovl_drop_write(dentry);
out:
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