This is a note to let you know that I've just added the patch titled
ovl: perform vfs_getxattr() with mounter creds
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ovl-perform-vfs_getxattr-with-mounter-creds.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit cedc5ac80e87fe4d49da40dd0c6b42bb2f65cf88
Author: Miklos Szeredi <mszeredi@xxxxxxxxxx>
Date: Thu Jan 28 10:22:48 2021 +0100
ovl: perform vfs_getxattr() with mounter creds
[ Upstream commit 554677b97257b0b69378bd74e521edb7e94769ff ]
The vfs_getxattr() in ovl_xattr_set() is used to check whether an xattr
exist on a lower layer file that is to be removed. If the xattr does not
exist, then no need to copy up the file.
This call of vfs_getxattr() wasn't wrapped in credential override, and this
is probably okay. But for consitency wrap this instance as well.
Reported-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index b584dca845baa..4fadafd8bdc12 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -346,7 +346,9 @@ int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
goto out;
if (!value && !upperdentry) {
+ old_cred = ovl_override_creds(dentry->d_sb);
err = vfs_getxattr(realdentry, name, NULL, 0);
+ revert_creds(old_cred);
if (err < 0)
goto out_drop_write;
}
