From: Christian Brauner <brauner@kernel.org>
To: Amir Goldstein <amir73il@gmail.com>,
Miklos Szeredi <miklos@szeredi.hu>,
"Darrick J . Wong" <djwong@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>, Christoph Hellwig <hch@lst.de>,
Seth Forshee <sforshee@kernel.org>,
Yang Xu <xuyang2018.jy@fujitsu.com>,
Filipe Manana <fdmanana@kernel.org>,
Christian Brauner <brauner@kernel.org>,
linux-unionfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
Miklos Szeredi <mszeredi@redhat.com>
Subject: [PATCH v3 5/5] ovl: remove privs in ovl_fallocate()
Date: Mon, 17 Oct 2022 12:06:00 +0200 [thread overview]
Message-ID: <20221017100600.70269-6-brauner@kernel.org> (raw)
In-Reply-To: <20221017100600.70269-1-brauner@kernel.org>
From: Amir Goldstein <amir73il@gmail.com>
Underlying fs doesn't remove privs because fallocate is called with
privileged mounter credentials.
This fixes some failure in fstests generic/683..687.
Fixes: aab8848cee5e ("ovl: add ovl_fallocate()")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Miklos Szeredi <mszeredi@redhat.com>
---
Notes:
/* v2 */
Acked-by: Miklos Szeredi <miklos@szeredi.hu>
/* v3 */
unchanged
fs/overlayfs/file.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index 755a11c63596..d066be3b9226 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -517,9 +517,16 @@ static long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len
const struct cred *old_cred;
int ret;
+ inode_lock(inode);
+ /* Update mode */
+ ovl_copyattr(inode);
+ ret = file_remove_privs(file);
+ if (ret)
+ goto out_unlock;
+
ret = ovl_real_fdget(file, &real);
if (ret)
- return ret;
+ goto out_unlock;
old_cred = ovl_override_creds(file_inode(file)->i_sb);
ret = vfs_fallocate(real.file, mode, offset, len);
@@ -530,6 +537,9 @@ static long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len
fdput(real);
+out_unlock:
+ inode_unlock(inode);
+
return ret;
}
--
2.34.1
prev parent reply other threads:[~2022-10-17 10:06 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-17 10:05 [PATCH v3 0/5] fs: improve setgid stripping consistency even more Christian Brauner
2022-10-17 10:05 ` [PATCH v3 1/5] attr: add setattr_drop_sgid() Christian Brauner
2022-10-17 12:00 ` Amir Goldstein
2022-10-17 10:05 ` [PATCH v3 2/5] attr: add setattr_should_drop_sgid() Christian Brauner
2022-10-17 12:03 ` Amir Goldstein
2022-10-17 10:05 ` [PATCH v3 3/5] attr: use consistent sgid stripping checks Christian Brauner
2022-10-17 11:59 ` Amir Goldstein
2022-10-17 12:05 ` Amir Goldstein
2022-10-17 10:05 ` [PATCH v3 4/5] ovl: remove privs in ovl_copyfile() Christian Brauner
2022-10-17 10:06 ` Christian Brauner [this message]
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