[PATCH 5.5 131/367] ovl: fix lseek overflow on 32bit

Greg Kroah-Hartman
2020-02-10T13:04:16Z

From: Miklos Szeredi <mszeredi@redhat.com>

commit a4ac9d45c0cd14a2adc872186431c79804b77dbf upstream.

ovl_lseek() is using ssize_t to return the value from vfs_llseek(). On a
32-bit kernel ssize_t is a 32-bit signed int, which overflows above 2 GB.

Assign the return value of vfs_llseek() to loff_t to fix this.

Reported-by: Boris Gjenero <boris.gjenero@gmail.com>
Fixes: 9e46b840c705 ("ovl: support stacked SEEK_HOLE/SEEK_DATA")
Cc: <stable@vger.kernel.org> # v4.19
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/overlayfs/file.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -146,7 +146,7 @@ static loff_t ovl_llseek(struct file *fi
struct inode *inode = file_inode(file);
struct fd real;
const struct cred *old_cred;
- ssize_t ret;
+ loff_t ret;

/*
* The two special cases below do not need to involve real fs,