From 1f5a81e41f8b1a782c68d3843e9ec1bfaadf7d72 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Wed, 2 Jun 2010 22:04:39 -0400 Subject: ext4: Make sure the MOVE_EXT ioctl can't overwrite append-only files From: Theodore Ts'o commit 1f5a81e41f8b1a782c68d3843e9ec1bfaadf7d72 upstream. Dan Roseberg has reported a problem with the MOVE_EXT ioctl. If the donor file is an append-only file, we should not allow the operation to proceed, lest we end up overwriting the contents of an append-only file. Signed-off-by: "Theodore Ts'o" Cc: Dan Rosenberg Signed-off-by: Greg Kroah-Hartman --- fs/ext4/move_extent.c | 3 +++ 1 file changed, 3 insertions(+) --- a/fs/ext4/move_extent.c +++ b/fs/ext4/move_extent.c @@ -959,6 +959,9 @@ mext_check_arguments(struct inode *orig_ return -EINVAL; } + if (IS_IMMUTABLE(donor_inode) || IS_APPEND(donor_inode)) + return -EPERM; + /* Ext4 move extent does not support swapfile */ if (IS_SWAPFILE(orig_inode) || IS_SWAPFILE(donor_inode)) { ext4_debug("ext4 move extent: The argument files should "