ext2: fix a block leak

open file, unlink it, then use ioctl(2) to make it immutable or
append only.  Now close it and watch the blocks *not* freed...

Immutable/append-only checks belong in ->setattr().
Note: the bug is old and backport to anything prior to 737f2e93b9
("ext2: convert to use the new truncate convention") will need
these checks lifted into ext2_setattr().

Cc: stable@kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2018-05-17 17:18:30 -04:00
parent 3819bb0d79
commit 5aa1437d2d
1 changed files with 0 additions and 10 deletions

View File

@ -1264,21 +1264,11 @@ do_indirects:
static void ext2_truncate_blocks(struct inode *inode, loff_t offset)
{
/*
* XXX: it seems like a bug here that we don't allow
* IS_APPEND inode to have blocks-past-i_size trimmed off.
* review and fix this.
*
* Also would be nice to be able to handle IO errors and such,
* but that's probably too much to ask.
*/
if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
S_ISLNK(inode->i_mode)))
return;
if (ext2_inode_is_fast_symlink(inode))
return;
if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
return;
dax_sem_down_write(EXT2_I(inode));
__ext2_truncate_blocks(inode, offset);