Date: Wed, 31 Mar 2021 19:21:44 -0600 From: Dan Raymond <draymond@...valley.net> To: Alan Coopersmith <alan.coopersmith@...cle.com>, libc-coord@...ts.openwall.com, Adhemerval Zanella <adhemerval.zanella@...aro.org>, libc-alpha@...rceware.org, Rich Felker <dalias@...c.org> Subject: Re: syslog and LOG_KERN - Re: [PATCH] Bug 3604: fix calls to openlog() with LOG_KERN facility On 3/31/2021 1:44 PM, Alan Coopersmith wrote: > On 3/31/21 12:27 PM, Adhemerval Zanella wrote: >> Not allowing LOG_KERN by any user process seems to be de facto behavior >> on all systems I am aware of: >> >> * FreeBSD and MUSL explicit set to previous log facility (they check >> if the priority against a mask and since on both LOG_KERN is 0 is >> set to the previous/default value). >> >> * Solaris 11.4 man page explicit says: >> >> LOG_KERN Messages generated by the kernel. These cannot >> be gener- >> ated by any user processes. > > The Solaris implementation is similar to FreeBSD & MUSL - LOG_KERN is 0, > so appears the same to syslog() as not specifying a facility and letting > the default value be used. It's a fair point that even with this patch the user can't explicitly specify LOG_KERN during a call to syslog(). To use LOG_KERN they must call openlog() first and set it as the default facility. That's a little clumsy but it is good enough to fix the klogd implementation in busybox. What is the alternative? To rewrite klogd so it bypasses syslog() altogether and writes directly to the syslogd socket? That seems inefficient and doesn't really achieve any security. If klogd can do this any user process can do it too.
Powered by blists - more mailing lists
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.