From 4507847c86bfc64e9bdce941a0f707560d3df98a Mon Sep 17 00:00:00 2001
From: Chao Yu <yuchao0@huawei.com>
Date: Wed, 17 Jul 2019 17:06:11 +0800
Subject: [PATCH] f2fs: support FS_IOC_{GET,SET}FSLABEL
Support two generic fs ioctls FS_IOC_{GET,SET}FSLABEL, letting
f2fs pass generic/492 testcase.
Fixes were made by Eric where:
- f2fs: fix buffer overruns in FS_IOC_{GET, SET}FSLABEL
utf16s_to_utf8s() and utf8s_to_utf16s() take the number of characters,
not the number of bytes.
- f2fs: fix copying too many bytes in FS_IOC_SETFSLABEL
Userspace provides a null-terminated string, so don't assume that the
full FSLABEL_MAX bytes can always be copied.
- f2fs: add missing authorization check in FS_IOC_SETFSLABEL
FS_IOC_SETFSLABEL modifies the filesystem superblock, so it shouldn't be
allowed to regular users. Require CAP_SYS_ADMIN, like xfs and btrfs do.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
fs/f2fs/f2fs.h | 3 +++
fs/f2fs/file.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 72 insertions(+)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 09ad4116d635d..d2b718e33f88e 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -418,6 +418,9 @@ static inline bool __has_cursum_space(struct f2fs_journal *journal,
#define F2FS_IOC_PRECACHE_EXTENTS _IO(F2FS_IOCTL_MAGIC, 15)
#define F2FS_IOC_RESIZE_FS _IOW(F2FS_IOCTL_MAGIC, 16, __u64)
+#define F2FS_IOC_GET_VOLUME_NAME FS_IOC_GETFSLABEL
+#define F2FS_IOC_SET_VOLUME_NAME FS_IOC_SETFSLABEL
+
#define F2FS_IOC_SET_ENCRYPTION_POLICY FS_IOC_SET_ENCRYPTION_POLICY
#define F2FS_IOC_GET_ENCRYPTION_POLICY FS_IOC_GET_ENCRYPTION_POLICY
#define F2FS_IOC_GET_ENCRYPTION_PWSALT FS_IOC_GET_ENCRYPTION_PWSALT
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index b1f38f2795bc9..344e0bd638e51 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -20,6 +20,7 @@
#include <linux/uio.h>
#include <linux/uuid.h>
#include <linux/file.h>
+#include <linux/nls.h>
#include "f2fs.h"
#include "node.h"
@@ -3081,6 +3082,68 @@ static int f2fs_ioc_resize_fs(struct file *filp, unsigned long arg)
return ret;
}
+static int f2fs_get_volume_name(struct file *filp, unsigned long arg)
+{
+ struct inode *inode = file_inode(filp);
+ struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+ char *vbuf;
+ int count;
+ int err = 0;
+
+ vbuf = f2fs_kzalloc(sbi, MAX_VOLUME_NAME, GFP_KERNEL);
+ if (!vbuf)
+ return -ENOMEM;
+
+ down_read(&sbi->sb_lock);
+ count = utf16s_to_utf8s(sbi->raw_super->volume_name,
+ ARRAY_SIZE(sbi->raw_super->volume_name),
+ UTF16_LITTLE_ENDIAN, vbuf, MAX_VOLUME_NAME);
+ up_read(&sbi->sb_lock);
+
+ if (copy_to_user((char __user *)arg, vbuf,
+ min(FSLABEL_MAX, count)))
+ err = -EFAULT;
+
+ kvfree(vbuf);
+ return err;
+}
+
+static int f2fs_set_volume_name(struct file *filp, unsigned long arg)
+{
+ struct inode *inode = file_inode(filp);
+ struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+ char *vbuf;
+ int err = 0;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ vbuf = strndup_user((const char __user *)arg, FSLABEL_MAX);
+ if (IS_ERR(vbuf))
+ return PTR_ERR(vbuf);
+
+ err = mnt_want_write_file(filp);
+ if (err)
+ goto out;
+
+ down_write(&sbi->sb_lock);
+
+ memset(sbi->raw_super->volume_name, 0,
+ sizeof(sbi->raw_super->volume_name));
+ utf8s_to_utf16s(vbuf, strlen(vbuf), UTF16_LITTLE_ENDIAN,
+ sbi->raw_super->volume_name,
+ ARRAY_SIZE(sbi->raw_super->volume_name));
+
+ err = f2fs_commit_super(sbi, false);
+
+ up_write(&sbi->sb_lock);
+
+ mnt_drop_write_file(filp);
+out:
+ kfree(vbuf);
+ return err;
+}
+
long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
int ret;
@@ -3144,6 +3207,10 @@ long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
return f2fs_ioc_precache_extents(filp, arg);
case F2FS_IOC_RESIZE_FS:
return f2fs_ioc_resize_fs(filp, arg);
+ case F2FS_IOC_GET_VOLUME_NAME:
+ return f2fs_get_volume_name(filp, arg);
+ case F2FS_IOC_SET_VOLUME_NAME:
+ return f2fs_set_volume_name(filp, arg);
default:
return -ENOTTY;
}
@@ -3253,6 +3320,8 @@ long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case F2FS_IOC_SET_PIN_FILE:
case F2FS_IOC_PRECACHE_EXTENTS:
case F2FS_IOC_RESIZE_FS:
+ case F2FS_IOC_GET_VOLUME_NAME:
+ case F2FS_IOC_SET_VOLUME_NAME:
break;
default:
return -ENOIOCTLCMD;