ext4: verify orphan file size is not too big

Browse source

commit 0a6ce20c15 upstream.

In principle orphan file can be arbitrarily large. However orphan replay
needs to traverse it all and we also pin all its buffers in memory. Thus
filesystems with absurdly large orphan files can lead to big amounts of
memory consumed. Limit orphan file size to a sane value and also use
kvmalloc() for allocating array of block descriptor structures to avoid
large order allocations for sane but large orphan files.

Reported-by: syzbot+0b92850d68d9b12934f5@syzkaller.appspotmail.com
Fixes: 02f310fcf4 ("ext4: Speedup ext4 orphan inode handling")
Cc: stable@kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Message-ID: <20250909112206.10459-2-jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

This commit is contained in:

Jan Kara 2025-09-09 13:22:07 +02:00 • committed by Greg Kroah-Hartman

parent e9663669a5

commit 2b9da798ff

1 changed files with 12 additions and 1 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

13

fs/ext4/orphan.c

View file