From d2d21512cbc681e73131077a6d88ff3799faa287 Mon Sep 17 00:00:00 2001
From: Oleksandr Tymoshenko <ovt@google.com>
Date: Wed, 30 Oct 2024 00:28:55 +0000
Subject: [PATCH] ovl: properly handle large files in ovl_security_fileattr
commit 3b6b99ef15ea37635604992ede9ebcccef38a239 upstream.
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+
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
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 c062f7e2ecb52..330c31bc99ecb 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -593,8 +593,13 @@ 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);
--
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