Re: apcupsd and wall+sendmail
[email protected] (Christos Zoulas)
| Newsgroups | gmane.os.netbsd.help |
|---|---|
| Message-ID | <[email protected]> |
In article <[email protected]>, Thierry Lacoste <[email protected]> wrote: >On Saturday 14 July 2007 14:49, David Laight wrote: >> On Sat, Jul 14, 2007 at 01:26:24PM +0200, Thierry Lacoste wrote: >> > Jul 12 11:42:27 vega /netbsd: set{u,g}id pid 29748 (sendmail) was invoked >> > by uid 0 ppid 1 (init) with fd 1,2 closed >> > Jul 12 11:42:27 vega /netbsd: set{u,g}id pid 2714 (wall) was invoked by >> > uid 0 ppid 1889 (sh) with fd 1,2 closed >> > >> > What do wall and sendmail messages mean? >> >> They are from the kernel. Basically programs and (worse) library code >> are likely to assume that fd 1 and 2 are connected to places they can >> write messages to. If you start a program with them closed, then they >> can be used for 'normal' file opens, and then writes to stdout/stderr >> can appear in the wring place. >> When this happens accidentally [1] is can be hard to debug, but for >> suid programs it could be a security issue. >> The kernel warnings are this suggesting that you fix whatever is >> closing the fds >Thanks David. I suspected something like this but I was not sure as this >does not happen on other BSDs. OpenBSD has the same code AFAIK. FreeBSD's is a bit different. christos