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-rw-r--r--NOFORK_NOEXEC.lst20
1 files changed, 11 insertions, 9 deletions
diff --git a/NOFORK_NOEXEC.lst b/NOFORK_NOEXEC.lst
index 14019bf7d..74922ff52 100644
--- a/NOFORK_NOEXEC.lst
+++ b/NOFORK_NOEXEC.lst
@@ -2,26 +2,28 @@ Why an applet can't be NOFORK or NOEXEC?
Why can't be NOFORK:
interactive: may wait for user input, ^C has to work
-spawner: "tool PROG ARGS" which changes program's environment - must fork
+spawner: "tool PROG ARGS" which changes program state and execs - must fork
changes state: e.g. environment, signal handlers
alloc+xfunc: xmalloc, then xfunc - leaks memory if xfunc dies
open+xfunc: opens fd, then calls xfunc - fd is leaked if xfunc dies
+leaks: does not free allocated memory or opened fds
runner: sometimes may run for long(ish) time, and/or works with network:
^C has to work (cat BIGFILE, chmod -R, ftpget, nc)
-"runners" can become eligible after shell is taught ^C to interrupt NOFORKs!
+"runners" can become eligible after shell is taught ^C to interrupt NOFORKs,
+need to be inspected that they do not fall into alloc+xfunc, open+xfunc
+categories.
Why can't be NOEXEC:
suid: runs under different uid - must fork+exec
Why shouldn't be NOFORK/NOEXEC:
-complex: no immediately obvious reason why NOFORK wouldn't work,
- but does some non-obvoius operations (example: fuser, lsof, losetup);
- nested xmallocs (typical in complex code) is a problem for NOFORK
-rare: not used often enough to bother optimizing (example: poweroff)
+rare: not started often enough to bother optimizing (example: poweroff)
+daemon: runs indefinitely; these are also always fit "rare" category
longterm: often runs for a long time (many seconds), execing would make
memory footprint smaller
-daemon: runs indefinitely
+complex: no immediately obvious reason why NOFORK wouldn't work,
+ but does some non-obvoius operations (example: fuser, lsof, losetup)
[ - NOFORK
[[ - NOFORK
@@ -59,7 +61,7 @@ chpasswd - runner (list of "user:password"s from stdin)
chpst - spawner
chroot - spawner
chrt - spawner
-chvt
+chvt - leaks: get_console_fd_or_die() may open a new fd, or return one of stdio fds. Also, "rare" category. Can be noexec.
cksum - noexec. runner
clear - NOFORK
cmp - runner
@@ -69,7 +71,7 @@ cp - noexec. runner
cpio - runner
crond - daemon
crontab
-cryptpw
+cryptpw - changes state: with --password-fd=N, moves N to stdin. Also, "rare" category. Can be noexec.
cttyhack - spawner
cut - noexec. runner
date - noexec. nofork candidate(needs to stop messing up env, free xasprintf result, not use xfuncs after xasprintf)