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auth/box: don't bother switching to none

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Changing the user to none doesn't do much for us
here. For kernel drivers that check the user of the
current proc we'll be none, but anything from devmnt
will still be accessed using creds from the original
attachment. Instead, running with none can be done
by chaining with auth/none:

auth/none auth/box ...
This commit is contained in:
Jacob Moody 2022-06-10 04:10:54 +00:00
parent 1b5ea51ee1
commit 13065e16b3
2 changed files with 17 additions and 25 deletions
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35
sys/man/8/auth
View file

@ -279,27 +279,24 @@ It's an easy way to run a command as
.IR none .
.PP
.I Box
sets up a restricted namespace and
.IR exec's
its arguments as the user
.IR none .
Components of the current namespace are bound
into the child namespace with the
.B -r
and
.B -c
flags, using either
.I MREPL
or
.I MCREATE
respectively. The only components
in the child namespace will be those
defined this way.
By default all further kernel driver
access is blocked. The
executes its arguments in a minimal namespace.
This namespace is derived by binding in the specified
program to the same name within a new hierarchy.
The same is done with the paths
provided as arguments. Paths provided with the
.B -r
flag are bound with
.IR MREPL ,
and those provided with the
.B -c
flag are bound with
.IR MCREATE .
.I Box
removes access to all kernel drivers from
the child namespace; the
.B -e
flag specifies a string of driver
characters to keep in the child namespace.
characters to keep.
.PP
.I As
executes

7
sys/src/cmd/auth/box.c
View file

@ -163,17 +163,12 @@ main(int argc, char **argv)
mflags[nparts++] = MREPL;
argv[0] = b;
rfork(RFNAMEG|RFENVG);
rfork(RFNAMEG|RFFDG);
dfd = open("/dev/drivers", OWRITE|OCEXEC);
if(dfd < 0)
sysfatal("could not /dev/drivers: %r");
resolvenames(parts, nparts);
if(procsetuser("none") < 0)
sysfatal("cant become none: %r");
putenv("user", "none");
sandbox(parts, mflags, nparts);
if(debug)