From: Akira Fujita Date: Thu, 4 Mar 2010 05:34:58 +0000 (-0500) Subject: ext4: Fix the NULL reference in double_down_write_data_sem() X-Git-Tag: v2.6.34-rc1~199^2~2 X-Git-Url: http://pileus.org/git/?a=commitdiff_plain;h=7247c0caa23d94a1cb6b307edba9dc45fb0798d4;p=~andy%2Flinux 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: Akira Fujita Signed-off-by: "Theodore Ts'o" --- diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c index 9eca1c0ec54..7e99f4e72bf 100644 --- a/fs/ext4/move_extent.c +++ b/fs/ext4/move_extent.c @@ -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)