On Wed, Oct 30, 2024 at 1:29 AM Oleksandr Tymoshenko <ovt@xxxxxxxxxx> 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@xxxxxxxxxx>
> Fixes: 72db82115d2b ("ovl: copy up sync/noatime fileattr flags")
> Cc: stable@xxxxxxxxxxxxxxx # 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
>
