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Commit 7247c0ca authored by Akira Fujita's avatar Akira Fujita Committed by Theodore Ts'o
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ext4: Fix the NULL reference in double_down_write_data_sem() 



If EXT4_IOC_MOVE_EXT ioctl is called with NULL donor_fd, fget() in
ext4_ioctl() gets inappropriate file structure for donor; so we need
to do this check earlier, before calling double_down_write_data_sem().

Signed-off-by: default avatarAkira Fujita <a-fujita@rs.jp.nec.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 5fd5249a

fs/ext4/move_extent.c

+8 −8
Original line number Diff line number Diff line
@@ -953,14 +953,6 @@ mext_check_arguments(struct inode *orig_inode, 
	unsigned int blkbits = orig_inode->i_blkbits;

	unsigned int blocksize = 1 << blkbits;



	/* Regular file check */

	if (!S_ISREG(orig_inode->i_mode) || !S_ISREG(donor_inode->i_mode)) {

		ext4_debug("ext4 move extent: The argument files should be "

			"regular file [ino:orig %lu, donor %lu]\n",

			orig_inode->i_ino, donor_inode->i_ino);

		return -EINVAL;

	}



	if (donor_inode->i_mode & (S_ISUID|S_ISGID)) {

		ext4_debug("ext4 move extent: suid or sgid is set"

			   " to donor file [ino:orig %lu, donor %lu]\n",
@@ -1208,6 +1200,14 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, 
		return -EINVAL;

	}



	/* Regular file check */

	if (!S_ISREG(orig_inode->i_mode) || !S_ISREG(donor_inode->i_mode)) {

		ext4_debug("ext4 move extent: The argument files should be "

			"regular file [ino:orig %lu, donor %lu]\n",

			orig_inode->i_ino, donor_inode->i_ino);

		return -EINVAL;

	}



	/* Protect orig and donor inodes against a truncate */

	ret1 = mext_inode_double_lock(orig_inode, donor_inode);

	if (ret1 < 0)