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authorKyle Evans <kevans@FreeBSD.org>2021-06-20 19:29:31 +0000
committerKyle Evans <kevans@FreeBSD.org>2021-07-19 04:05:48 +0000
commit7a129c973b5ba0fa916dfa658d523bec66dbd02d (patch)
tree198d64b5a995411511682782b088d31ebe05e766 /sys
parent46438b5366f9405beb6f76474a5aae822352f012 (diff)
downloadsrc-7a129c973b5ba0fa916dfa658d523bec66dbd02d.tar.gz
src-7a129c973b5ba0fa916dfa658d523bec66dbd02d.zip
kern: add an option for preserving the early kenv
Some downstream configurations do not store secrets in the early (loader/static) environments and desire a way to preserve these for diagnostic reasons. Provide an option to do so. Reviewed by: imp, jhb (earlier version) Differential Revision: https://reviews.freebsd.org/D30834
Diffstat (limited to 'sys')
-rw-r--r--sys/conf/options8
-rw-r--r--sys/kern/kern_environment.c4
2 files changed, 12 insertions, 0 deletions
diff --git a/sys/conf/options b/sys/conf/options
index 882460fbf35b..774850158221 100644
--- a/sys/conf/options
+++ b/sys/conf/options
@@ -1021,3 +1021,11 @@ IICHID_DEBUG opt_hid.h
IICHID_SAMPLING opt_hid.h
HKBD_DFLT_KEYMAP opt_hkbd.h
HIDRAW_MAKE_UHID_ALIAS opt_hid.h
+
+# kenv options
+# The early kernel environment (loader environment, config(8)-provided static)
+# is typically cleared after the dynamic environment comes up to ensure that
+# we're not inadvertently holding on to 'secret' values in these stale envs.
+# This option is insecure except in controlled environments where the static
+# environment's contents are known to be safe.
+PRESERVE_EARLY_KENV opt_global.h
diff --git a/sys/kern/kern_environment.c b/sys/kern/kern_environment.c
index 54992e6594ed..8dc345559e95 100644
--- a/sys/kern/kern_environment.c
+++ b/sys/kern/kern_environment.c
@@ -365,7 +365,11 @@ init_dynamic_kenv_from(char *init_env, int *curpos)
kenvp[i] = malloc(len, M_KENV, M_WAITOK);
strcpy(kenvp[i++], cp);
sanitize:
+#ifdef PRESERVE_EARLY_KENV
+ continue;
+#else
explicit_bzero(cp, len - 1);
+#endif
}
*curpos = i;
}