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authorGravatar Denys Vlasenko <vda.linux@googlemail.com>2017-08-04 17:36:16 +0200
committerGravatar Denys Vlasenko <vda.linux@googlemail.com>2017-08-04 17:36:16 +0200
commit74c05f5b2cfde7a561e55437eb499f96864179a3 (patch)
treed2f84f2fcf5ab032a58bc37c6a0b6f0d6f273c9b
parentdd5a40246b91bd5d3d165998e6ac3cc4f7083f63 (diff)
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chat: trim help text
Noticed while auditing nofork/noexec status function old new delta packed_usage 31777 31747 -30 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--NOFORK_NOEXEC.lst93
-rw-r--r--miscutils/chat.c4
-rw-r--r--util-linux/freeramdisk.c8
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);