From: Theodore Ts'o Date: Wed, 21 Dec 2011 19:14:31 +0000 (-0500) Subject: ext4: remove unneeded file_remove_suid() from ext4_ioctl() X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=22cdfca5641817060dd724a9c30442f5c0675fcd;p=linux-beck.git ext4: remove unneeded file_remove_suid() from ext4_ioctl() In the code to support EXT4_IOC_MOVE_EXT, ext4_ioctl calls file_remove_suid() after the call to ext4_move_extents() if any extents has been moved. There are at least three things wrong with this. First, file_remove_suid() should be called with i_mutex down, which is not here. Second, it should be called before the donor file has been modified, to avoid a potential race condition. Third, and most importantly, it's pointless, because ext4_file_extents() already checks if the donor file has the setuid or setgid bit set, and will return an error in that case. So the first two objections don't really matter, since file_remove_suid() will never need to modify the inode in any case. Signed-off-by: "Theodore Ts'o" --- diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index a56796814d6a..ff1aab7cd6e8 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -247,8 +247,6 @@ setversion_out: err = ext4_move_extents(filp, donor_filp, me.orig_start, me.donor_start, me.len, &me.moved_len); mnt_drop_write(filp->f_path.mnt); - if (me.moved_len > 0) - file_remove_suid(donor_filp); if (copy_to_user((struct move_extent __user *)arg, &me, sizeof(me)))