On Wed, Oct 30, 2024 at 1:29 AM Oleksandr Tymoshenko ovt@google.com wrote:

dentry_open in ovl_security_fileattr fails for any file larger than 2GB if open method of the underlying filesystem calls generic_file_open (e.g. fusefs).

The issue can be reproduce using the following script: (passthrough_ll is an example app from libfuse).

$ D=/opt/test/mnt $ mkdir -p ${D}/{source,base,top/uppr,top/work,ovlfs} $ dd if=/dev/zero of=${D}/source/zero.bin bs=1G count=2 $ passthrough_ll -o source=${D}/source ${D}/base $ mount -t overlay overlay \ -olowerdir=${D}/base,upperdir=${D}/top/uppr,workdir=${D}/top/work \ ${D}/ovlfs $ chmod 0777 ${D}/mnt/ovlfs/zero.bin

Running this script results in "Value too large for defined data type" error message from chmod.

Signed-off-by: Oleksandr Tymoshenko ovt@google.com Fixes: 72db82115d2b ("ovl: copy up sync/noatime fileattr flags") Cc: stable@vger.kernel.org # v5.15+

Applied.

Thanks, Amir,

---

fs/overlayfs/inode.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 35fd3e3e1778..baa54c718bd7 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -616,8 +616,13 @@ static int ovl_security_fileattr(const struct path *realpath, struct fileattr *f struct file *file; unsigned int cmd; int err;

•   unsigned int flags;
  

•   flags = O_RDONLY;
  

•   if (force_o_largefile())
  

•           flags |= O_LARGEFILE;
  
  

•   file = dentry_open(realpath, O_RDONLY, current_cred());
  

•   file = dentry_open(realpath, flags, current_cred());
    if (IS_ERR(file))
            return PTR_ERR(file);
  
  

-- 2.47.0.163.g1226f6d8fa-goog