diff options
| author | Amir Goldstein <amir73il@gmail.com> | 2019-01-22 07:01:39 +0200 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2019-05-06 13:54:50 +0200 |
| commit | 3428030da004a1128cbdcf93dc03e16f184d845b (patch) | |
| tree | fa8bdd8c7fa12a50499519fe18123e4b271263d1 /fs/overlayfs/file.c | |
| parent | e93c9c99a629c61837d5a7fc2120cd2b6c70dbdd (diff) | |
ovl: fix missing upper fs freeze protection on copy up for ioctl
Generalize the helper ovl_open_maybe_copy_up() and use it to copy up file
with data before FS_IOC_SETFLAGS ioctl.
The FS_IOC_SETFLAGS ioctl is a bit of an odd ball in vfs, which probably
caused the confusion. File may be open O_RDONLY, but ioctl modifies the
file. VFS does not call mnt_want_write_file() nor lock inode mutex, but
fs-specific code for FS_IOC_SETFLAGS does. So ovl_ioctl() calls
mnt_want_write_file() for the overlay file, and fs-specific code calls
mnt_want_write_file() for upper fs file, but there was no call for
ovl_want_write() for copy up duration which prevents overlayfs from copying
up on a frozen upper fs.
Fixes: dab5ca8fd9dd ("ovl: add lsattr/chattr support")
Cc: <stable@vger.kernel.org> # v4.19
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/overlayfs/file.c')
| -rw-r--r-- | fs/overlayfs/file.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c index 84dd957efa24..50e4407398d8 100644 --- a/fs/overlayfs/file.c +++ b/fs/overlayfs/file.c @@ -116,11 +116,10 @@ static int ovl_real_fdget(const struct file *file, struct fd *real) static int ovl_open(struct inode *inode, struct file *file) { - struct dentry *dentry = file_dentry(file); struct file *realfile; int err; - err = ovl_open_maybe_copy_up(dentry, file->f_flags); + err = ovl_maybe_copy_up(file_dentry(file), file->f_flags); if (err) return err; @@ -390,7 +389,7 @@ static long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg) if (ret) return ret; - ret = ovl_copy_up_with_data(file_dentry(file)); + ret = ovl_maybe_copy_up(file_dentry(file), O_WRONLY); if (!ret) { ret = ovl_real_ioctl(file, cmd, arg); |