From 74c05f5b2cfde7a561e55437eb499f96864179a3 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Fri, 4 Aug 2017 17:36:16 +0200 Subject: [PATCH] chat: trim help text Noticed while auditing nofork/noexec status function old new delta packed_usage 31777 31747 -30 Signed-off-by: Denys Vlasenko --- NOFORK_NOEXEC.lst | 93 +++++++++++++++++++++------------------- miscutils/chat.c | 4 +- util-linux/freeramdisk.c | 8 +++- 3 files changed, 58 insertions(+), 47 deletions(-) diff --git a/NOFORK_NOEXEC.lst b/NOFORK_NOEXEC.lst index 74922ff52..9741f21ea 100644 --- a/NOFORK_NOEXEC.lst +++ b/NOFORK_NOEXEC.lst @@ -11,8 +11,8 @@ 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, -need to be inspected that they do not fall into alloc+xfunc, open+xfunc -categories. +need to be inspected that they do not fall into alloc+xfunc, open+xfunc, +leak categories. Why can't be NOEXEC: suid: runs under different uid - must fork+exec @@ -23,7 +23,15 @@ 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 complex: no immediately obvious reason why NOFORK wouldn't work, - but does some non-obvoius operations (example: fuser, lsof, losetup) + but does some non-obvoius operations (example: fuser, lsof, losetup); + detailed audit often turns out that it's a leaker + +Interesting example of "interactive" applet which is nevertheless can be +(and is) NOEXEC is "rm". Yes, "rm -i" is interactive - but it's not that typical +for users to keep it waiting for many minutes, whereas running "rm" in shell +is very typical, and speeding up this common use via NOEXEC is useful. +IOW: rm is "interactive", but not "longterm". + [ - NOFORK [[ - NOFORK @@ -34,9 +42,9 @@ adduser adjtimex ar - runner arch - NOFORK -arp +arp - complex, rare arping - runner -ash - interactive +ash - interactive, longterm awk - noexec. runner base64 - runner basename - NOFORK @@ -52,7 +60,7 @@ bzcat - runner bzip2 - runner cal - runner: cal -n9999 cat - runner -chat +chat - needs ^C to work chattr - runner chgrp - noexec. runner chmod - noexec. runner @@ -77,10 +85,10 @@ cut - noexec. runner date - noexec. nofork candidate(needs to stop messing up env, free xasprintf result, not use xfuncs after xasprintf) dc - runner (eats stdin if no params) dd - noexec. runner -deallocvt +deallocvt - leaks: get_console_fd_or_die() may open a new fd, or return one of stdio fds. Also, "rare" category. Can be noexec. delgroup deluser -depmod +depmod - complex, rare devmem - runner, complex (access to device memory may hang) df - complex (nested allocs) dhcprelay - daemon @@ -88,16 +96,16 @@ diff - runner dirname - NOFORK dmesg - runner dnsd - daemon -dnsdomainname - DNS resolution may trigger, need ^C +dnsdomainname - needs ^C (may talk to DNS servers, which may be down) dos2unix - noexec. runner dpkg - runner du - runner -dumpkmap +dumpkmap - leaks: get_console_fd_or_die() may open a new fd, or return one of stdio fds. Also, "rare" category. Can be noexec. dumpleases echo - NOFORK -ed - interactive -egrep - runner -eject +ed - interactive, longterm +egrep - longterm runner ("CMD | egrep ..." may run indefinitely, better to exec to conserve memory) +eject - leaks: open+ioctl_or_perror_and_die, changes state (moves fds) env - noexec. changes state (env) envdir - spawner envuidgid - spawner @@ -107,24 +115,24 @@ factor - runner (eats stdin if no params) fakeidentd - daemon false - NOFORK fatattr - complex (xopen+xioctl can leak fd) -fbset -fbsplash - runner, interactive -fdflush -fdformat - runner -fdisk - interactive -fgconsole -fgrep - runner +fbset - leaks: open+xfunc, complex, rare +fbsplash - runner, longterm +fdflush - leaks: open+ioctl_or_perror_and_die, needs ^C (floppy may be unresponsive), rare +fdformat - needs ^C (floppy may be unresponsive), longterm, rare +fdisk - interactive, longterm +fgconsole - leaks: get_console_fd_or_die() may open a new fd, or return one of stdio fds. Also, "rare" category. Can be noexec. +fgrep - longterm runner ("CMD | fgrep ..." may run indefinitely, better to exec to conserve memory) find - noexec. runner findfs - suid flash_eraseall flash_lock flash_unlock flashcp -flock +flock - spawner, changes state (file locks) fold - noexec. runner free - nofork candidate(struct globals, needs to close /proc/meminfo fd) -freeramdisk -fsck - interactive +freeramdisk - leaks: open+ioctl_or_perror_and_die +fsck - interactive, longterm fsck.minix fsfreeze fstrim @@ -134,8 +142,8 @@ ftpget - runner ftpput - runner fuser - complex getopt - noexec. complex (many allocs) -getty - interactive -grep - runner +getty - interactive, longterm +grep - longterm runner ("CMD | grep ..." may run indefinitely, better to exec to conserve memory) groups - noexec gunzip - runner gzip - runner @@ -147,7 +155,7 @@ hexdump - noexec. runner hostid - NOFORK hostname - DNS resolution may trigger, need ^C httpd - daemon -hush - interactive +hush - interactive, longterm hwclock i2cdetect i2cdump @@ -180,39 +188,39 @@ killall - NOFORK killall5 - NOFORK klogd - daemon last - runner (I've got 1300 lines of output when tried it) -less - interactive +less - interactive, longterm link - NOFORK linux32 - spawner linux64 - spawner linuxrc - daemon ln - noexec loadfont -loadkmap +loadkmap - leaks: get_console_fd_or_die() may open a new fd, or return one of stdio fds. Also, "rare" category. Can be noexec. logger - runner -login - suid, interactive +login - suid, interactive, longterm logname - NOFORK losetup - complex lpd - daemon lpq - runner lpr - runner ls - noexec. runner -lsattr +lsattr - runner. noexec candidate (ls is, why not this one?) lsmod - noexec lsof - complex -lspci -lsscsi -lsusb +lspci - noexec candidate, too rare to bother for nofork +lsscsi - noexec candidate, too rare to bother for nofork +lsusb - noexec candidate, too rare to bother for nofork lzcat - runner lzma - runner lzop - runner lzopcat - runner makedevs makemime - runner -man - spawner, interactive +man - spawner, interactive, longterm md5sum - noexec. runner mdev - daemon mesg -microcom - interactive, complex +microcom - interactive, longterm mkdir - NOFORK mkdosfs mke2fs @@ -223,10 +231,10 @@ mkfs.vfat mknod - noexec mkpasswd mkswap -mktemp +mktemp - leaks: xstrdup+concat_path_file modinfo - noexec modprobe - noexec -more - interactive +more - interactive, longterm mount - suid mountpoint mpstat @@ -305,12 +313,11 @@ setpriv - spawner setserial setsid - spawner setuidgid -sh - interactive sha1sum - noexec. runner sha256sum - noexec. runner sha3sum - noexec. runner sha512sum - noexec. runner -showkey - interactive +showkey - interactive, longterm shred - runner shuf - noexec. runner slattach @@ -342,7 +349,7 @@ tar - runner taskset - spawner tcpsvd - daemon tee - runner -telnet - interactive +telnet - interactive, longterm telnetd - daemon test - NOFORK tftp - runner @@ -359,7 +366,7 @@ truncate - NOFORK tty - NOFORK ttysize - NOFORK tunctl -tune2fs +tune2fs - leaks: open+xfunc ubiattach ubidetach ubimkvol @@ -387,8 +394,8 @@ users - nofork candidate(is getutxent ok?) usleep - NOFORK uudecode - runner uuencode - runner -vconfig -vi - interactive +vconfig - leaks: xsocket+ioctl_or_perror_and_die +vi - interactive, longterm vlock - suid volname - runner w diff --git a/miscutils/chat.c b/miscutils/chat.c index 216a899a0..1446a040c 100644 --- a/miscutils/chat.c +++ b/miscutils/chat.c @@ -82,8 +82,8 @@ //usage: "EXPECT [SEND [EXPECT [SEND...]]]" //usage:#define chat_full_usage "\n\n" //usage: "Useful for interacting with a modem connected to stdin/stdout.\n" -//usage: "A script consists of one or more \"expect-send\" pairs of strings,\n" -//usage: "each pair is a pair of arguments. Example:\n" +//usage: "A script consists of \"expect-send\" argument pairs.\n" +//usage: "Example:\n" //usage: "chat '' ATZ OK ATD123456 CONNECT '' ogin: pppuser word: ppppass '~'" #include "libbb.h" diff --git a/util-linux/freeramdisk.c b/util-linux/freeramdisk.c index 55187cb40..a73578404 100644 --- a/util-linux/freeramdisk.c +++ b/util-linux/freeramdisk.c @@ -67,8 +67,12 @@ int freeramdisk_main(int argc UNUSED_PARAM, char **argv) fd = xopen(single_argv(argv), O_RDWR); // Act like freeramdisk, fdflush, or both depending on configuration. - ioctl_or_perror_and_die(fd, (ENABLE_FREERAMDISK && applet_name[1] == 'r') - || !ENABLE_FDFLUSH ? BLKFLSBUF : FDFLUSH, NULL, "%s", argv[1]); + ioctl_or_perror_and_die(fd, + ((ENABLE_FREERAMDISK && applet_name[1] == 'r') || !ENABLE_FDFLUSH) + ? BLKFLSBUF + : FDFLUSH, + NULL, "%s", argv[1] + ); if (ENABLE_FEATURE_CLEAN_UP) close(fd); -- 2.25.1