Bugtraq mailing list archives
Re: Symlinks and Cryogenic Sleep
From: mouse () RODENTS MONTREAL QC CA (der Mouse)
Date: Mon, 3 Jan 2000 21:04:27 -0500
[symlink-paranoia code]
However, consider an average setuid root application, [...]. When the application reaches the critical section of code between the lstat and the open, you stop it by sending it a SIGSTOP.
If you can send it a SIGSTOP, either you're running as root (in which case you don't *need* to play with symlink races), the application is running as you (in which case breaking it buys you nothing), or signal delivery is critically broken. In fact, I suspect that any process you can SIGSTOP, you can attach to with ptrace and do whatever you want without need for subtrefuge.
--for instance a lookup of /tmp/foo (as done by lstat()) will change the directory's atime.
"That turns out not to be the case." Or at least, you can't count on it: [Sparkle] 115> ls -ldu /tmp drwxrwxrwt 24 root 2560 Jan 2 21:15 /tmp [Sparkle] 116> date Mon Jan 3 23:15:27 EST 2000 [Sparkle] 117> ls -ld /tmp/foobar /tmp/foobar not found [Sparkle] 118> ls -ldu /tmp drwxrwxrwt 24 root 2560 Jan 2 21:15 /tmp [Sparkle] 119> der Mouse mouse () rodents montreal qc ca 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B
Current thread:
- Re: Symlinks and Cryogenic Sleep, (continued)
- Re: Symlinks and Cryogenic Sleep pedward () WEBCOM COM (Jan 04)
- Re: Symlinks and Cryogenic Sleep Christos Zoulas (Jan 04)
- Re: Symlinks and Cryogenic Sleep Mikael Olsson (Jan 05)
- Re: Symlinks and Cryogenic Sleep Marc Heuse (Jan 05)
- Re: Symlinks and Cryogenic Sleep Wietse Venema (Jan 04)
- Re: Symlinks and Cryogenic Sleep Pavel Machek (Jan 04)
- Security problem with Solstice Backup/Legato Networker recover command Chris Siebenmann (Jan 04)
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- Re: Symlinks and Cryogenic Sleep Pavel Kankovsky (Jan 05)
- [RHSA-2000:002] New lpr packages available Bill Nottingham (Jan 07)
- Re: Symlinks and Cryogenic Sleep der Mouse (Jan 03)
- Re: Symlinks and Cryogenic Sleep Marc Heuse (Jan 04)
- Re: Symlinks and Cryogenic Sleep John Cochran (Jan 04)
- Re: Symlinks and Cryogenic Sleep Antonomasia (Jan 04)
- Re: Symlinks and Cryogenic Sleep Antonomasia (Jan 05)