From d591256a5cf9c744b9d95f7b0055dce8528a63ca Mon Sep 17 00:00:00 2001 From: Euan Harris Date: Fri, 4 May 2018 16:18:47 +0100 Subject: [PATCH] nsenter: fix parsing of -t, -S and -G options -t, -S and -G each take mandatory integer arguments. getopt32long()'s option string syntax for this type of argument is 'c:+', however nsenter's opt_str uses 'c+', which specifies two options 'c' and '+' which do not take arguments. This means that giving a target PID causes nsenter to exit and print the usage string: # nsenter -t1 sh nsenter: unrecognized option: 1 BusyBox v1.27.2 (2017-12-12 10:41:50 GMT) multi-call binary. ... The long form options are also broken: # nsenter --setuid=1000 --setgid=1000 sh BusyBox v1.29.0.git (2018-05-04 13:56:49 UTC) multi-call binary. ... `nsenter --target= sh` parses correctly and appears to work, but is ignored and set to 0. This doesn't raise an error unless one of the namespace arguments is also given: # ./busybox_unstripped nsenter --target=42 sh # exit # ./busybox_unstripped nsenter -n --target=42 sh BusyBox v1.29.0.git (2018-05-04 13:56:49 UTC) multi-call binary. ... This has caused problems in a couple of places: https://github.com/linuxkit/linuxkit/issues/567 https://github.com/gliderlabs/docker-alpine/issues/359 https://github.com/kontena/pharos-cluster/pull/81 Signed-off-by: Euan Harris Signed-off-by: Denys Vlasenko --- util-linux/nsenter.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/util-linux/nsenter.c b/util-linux/nsenter.c index 35439a2ab..ae8103a52 100644 --- a/util-linux/nsenter.c +++ b/util-linux/nsenter.c @@ -105,7 +105,7 @@ static const struct namespace_descr ns_list[] = { /* * Upstream nsenter doesn't support the short option for --preserve-credentials */ -static const char opt_str[] ALIGN1 = "U::i::u::n::p::m::""t+S+G+r::w::F"; +static const char opt_str[] ALIGN1 = "U::i::u::n::p::m::""t:+S:+G:+r::w::F"; #if ENABLE_LONG_OPTS static const char nsenter_longopts[] ALIGN1 = -- 2.25.1