Bugtraq mailing list archives
Re: Linux kernel filesystem oddities
From: peak () kerberos troja mff cuni cz (Pavel Kankovsky)
Date: Wed, 8 Jul 1998 22:42:21 +0200
On Mon, 6 Jul 1998, Michal Zalewski wrote:
FIFO itself occupies a single inode, no block, therefore charging inode quota but not block quota is correct.It's not charged at all. Set inode quota to something reasonable, then create any amount FIFOs in /tmp.
Argh. You're right. There is this STUPID statement at the beginning of dquot_initialize() (fs/dquot.c): if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) This is a bug!
But there will be problem with hard-links - creator of this object is...Hardlink is not a fs object, it is a directory entry.Yep. I mean, we need more information about these entries - who really CREATED entry... But it's a major change in filesystem architecture and I don't think it's possible...
It would be rather confusing if directory entries themselves had their own attributes.
The world writable directory is a real problem. It is similar to world writable files: anyone can use them to store data on its owner.They are not similar, because directory stores data about owner of entries in it. Kernel provides mechanism to limit it, but unfortunately, this mechanism is waek.
Owners are stored in i-nodes. Directory entries are nothing but (filename, i-node number) pairs. link("publicly-visible-file", "world-writable-directory/blah") is as anonymous as write(open("/world-writable-file", O_WRONLY), "blah", 4) --Pavel Kankovsky aka Peak [ Boycott Microsoft--http://www.vcnet.com/bms ] "You can't be truly paranoid unless you're sure they have already got you."
Current thread:
- SmurfLog 1.0 Bug Lord (Jul 03)
- Linux kernel filesystem oddities Michal Zalewski (Jul 05)
- sentry Paul Boehm (Jul 08)
- Re: Linux kernel filesystem oddities Pavel Kankovsky (Jul 08)
- Re: Linux kernel filesystem oddities Michal Zalewski (Jul 06)
- Re: Linux kernel filesystem oddities Pavel Kankovsky (Jul 08)
- Re: Linux kernel filesystem oddities Jeffrey Hutzelman (Jul 09)
- dslip package David Kopstain (Jul 09)
- SLMail 3.0.2421 Stack Overflow... Aleph One (Jul 09)
- Linux kernel filesystem oddities Michal Zalewski (Jul 05)
- Re: SmurfLog 1.0 Bug Lord (Jul 10)
- Re: port 0 scanning Lamont Granquist (Jul 09)
- Regarding Mudge's OBP/FORTH root hack (PHRACK53) Jericho Nunn (Jul 10)
- Re: Regarding Mudge's OBP/FORTH root hack (PHRACK53) John W. Temples (Jul 11)
- Re: Regarding Mudge's OBP/FORTH root hack (PHRACK53) Casper Dik (Jul 13)