On 11/1/2022 5:05 PM, Kees Cook wrote: > Enhance the details reported by "lsm.debug" in several ways: > > - report contents of "security=" > - report contents of "CONFIG_LSM" > - report contents of "lsm=" > - report any early LSM details > - whitespace-align the output of similar phases for easier visual parsing > - change "disabled" to more accurate "skipped" > - explain what "skipped" and "ignored" mean in a parenthetical > > Upgrade the "security= is ignored" warning from pr_info to pr_warn, > and include full arguments list to make the cause even more clear. > > Replace static "Security Framework initializing" pr_info with specific > list of the resulting order of enabled LSMs. > > For example, if the kernel is built with: > > CONFIG_SECURITY_SELINUX=y > CONFIG_SECURITY_APPARMOR=y > CONFIG_SECURITY_LOADPIN=y > CONFIG_SECURITY_YAMA=y > CONFIG_SECURITY_SAFESETID=y > CONFIG_SECURITY_LOCKDOWN_LSM=y > CONFIG_SECURITY_LANDLOCK=y > CONFIG_INTEGRITY=y > CONFIG_BPF_LSM=y > CONFIG_DEFAULT_SECURITY_APPARMOR=y > CONFIG_LSM="landlock,lockdown,yama,loadpin,safesetid,integrity,selinux,smack,tomoyo,apparmor,bpf" > > Booting without options will show: > > LSM: initializing lsm=lockdown,capability,landlock,yama,loadpin,safesetid,integrity,selinux,bpf > landlock: Up and running. > Yama: becoming mindful. > LoadPin: ready to pin (currently not enforcing) > SELinux: Initializing. > LSM support for eBPF active > > Boot with "lsm.debug" will show: > > LSM: legacy security= *unspecified* > LSM: CONFIG_LSM=landlock,lockdown,yama,loadpin,safesetid,integrity,selinux,smack,tomoyo,apparmor,bpf > LSM: boot arg lsm= *unspecified* > LSM: early started: lockdown (enabled) > LSM: first ordered: capability (enabled) > LSM: builtin ordered: landlock (enabled) > LSM: builtin ignored: lockdown (not built into kernel) > LSM: builtin ordered: yama (enabled) > LSM: builtin ordered: loadpin (enabled) > LSM: builtin ordered: safesetid (enabled) > LSM: builtin ordered: integrity (enabled) > LSM: builtin ordered: selinux (enabled) > LSM: builtin ignored: smack (not built into kernel) > LSM: builtin ignored: tomoyo (not built into kernel) > LSM: builtin ordered: apparmor (enabled) > LSM: builtin ordered: bpf (enabled) > LSM: exclusive chosen: selinux > LSM: exclusive disabled: apparmor > LSM: initializing lsm=lockdown,capability,landlock,yama,loadpin,safesetid,integrity,selinux,bpf > LSM: cred blob size = 32 > LSM: file blob size = 16 > LSM: inode blob size = 72 > LSM: ipc blob size = 8 > LSM: msg_msg blob size = 4 > LSM: superblock blob size = 80 > LSM: task blob size = 8 > LSM: initializing capability > LSM: initializing landlock > landlock: Up and running. > LSM: initializing yama > Yama: becoming mindful. > LSM: initializing loadpin > LoadPin: ready to pin (currently not enforcing) > LSM: initializing safesetid > LSM: initializing integrity > LSM: initializing selinux > SELinux: Initializing. > LSM: initializing bpf > LSM support for eBPF active > > And some examples of how the lsm.debug ordering report changes... > > With "lsm.debug security=selinux": > > LSM: legacy security=selinux > LSM: CONFIG_LSM=landlock,lockdown,yama,loadpin,safesetid,integrity,selinux,smack,tomoyo,apparmor,bpf > LSM: boot arg lsm= *unspecified* > LSM: early started: lockdown (enabled) > LSM: first ordered: capability (enabled) > LSM: security=selinux disabled: apparmor (only one legacy major LSM) > LSM: builtin ordered: landlock (enabled) > LSM: builtin ignored: lockdown (not built into kernel) > LSM: builtin ordered: yama (enabled) > LSM: builtin ordered: loadpin (enabled) > LSM: builtin ordered: safesetid (enabled) > LSM: builtin ordered: integrity (enabled) > LSM: builtin ordered: selinux (enabled) > LSM: builtin ignored: smack (not built into kernel) > LSM: builtin ignored: tomoyo (not built into kernel) > LSM: builtin ordered: apparmor (disabled) > LSM: builtin ordered: bpf (enabled) > LSM: exclusive chosen: selinux > LSM: initializing lsm=lockdown,capability,landlock,yama,loadpin,safesetid,integrity,selinux,bpf > > With "lsm.debug lsm=integrity,selinux,loadpin,crabability,bpf,loadpin,loadpin": > > LSM: legacy security= *unspecified* > LSM: CONFIG_LSM=landlock,lockdown,yama,loadpin,safesetid,integrity,selinux,smack,tomoyo,apparmor,bpf > LSM: boot arg lsm=integrity,selinux,loadpin,capability,bpf,loadpin,loadpin > LSM: early started: lockdown (enabled) > LSM: first ordered: capability (enabled) > LSM: cmdline ordered: integrity (enabled) > LSM: cmdline ordered: selinux (enabled) > LSM: cmdline ordered: loadpin (enabled) > LSM: cmdline ignored: crabability (not built into kernel) > LSM: cmdline ordered: bpf (enabled) > LSM: cmdline skipped: apparmor (not in requested order) > LSM: cmdline skipped: yama (not in requested order) > LSM: cmdline skipped: safesetid (not in requested order) > LSM: cmdline skipped: landlock (not in requested order) > LSM: exclusive chosen: selinux > LSM: initializing lsm=lockdown,capability,integrity,selinux,loadpin,bpf > > Cc: Paul Moore <paul@xxxxxxxxxxxxxx> > Cc: James Morris <jmorris@xxxxxxxxx> > Cc: "Serge E. Hallyn" <serge@xxxxxxxxxx> > Cc: linux-security-module@xxxxxxxxxxxxxxx > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> Acked-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx> I'm curious about what is driving this change. > --- > v2: en/dis-enabled expanded, example output in commit log, use pr_cont. > v1: https://lore.kernel.org/lkml/20221018064825.never.323-kees@xxxxxxxxxx/ > --- > security/security.c | 45 ++++++++++++++++++++++++++++++++++++--------- > 1 file changed, 36 insertions(+), 9 deletions(-) > > diff --git a/security/security.c b/security/security.c > index 79d82cb6e469..abceabda103d 100644 > --- a/security/security.c > +++ b/security/security.c > @@ -161,8 +161,8 @@ static void __init append_ordered_lsm(struct lsm_info *lsm, const char *from) > lsm->enabled = &lsm_enabled_true; > ordered_lsms[last_lsm++] = lsm; > > - init_debug("%s ordering: %s (%sabled)\n", from, lsm->name, > - is_enabled(lsm) ? "en" : "dis"); > + init_debug("%s ordered: %s (%s)\n", from, lsm->name, > + is_enabled(lsm) ? "enabled" : "disabled"); > } > > /* Is an LSM allowed to be initialized? */ > @@ -224,7 +224,7 @@ static void __init prepare_lsm(struct lsm_info *lsm) > if (enabled) { > if ((lsm->flags & LSM_FLAG_EXCLUSIVE) && !exclusive) { > exclusive = lsm; > - init_debug("exclusive chosen: %s\n", lsm->name); > + init_debug("exclusive chosen: %s\n", lsm->name); > } > > lsm_set_blob_sizes(lsm->blobs); > @@ -252,7 +252,7 @@ static void __init ordered_lsm_parse(const char *order, const char *origin) > /* LSM_ORDER_FIRST is always first. */ > for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) { > if (lsm->order == LSM_ORDER_FIRST) > - append_ordered_lsm(lsm, "first"); > + append_ordered_lsm(lsm, " first"); > } > > /* Process "security=", if given. */ > @@ -270,7 +270,7 @@ static void __init ordered_lsm_parse(const char *order, const char *origin) > if ((major->flags & LSM_FLAG_LEGACY_MAJOR) && > strcmp(major->name, chosen_major_lsm) != 0) { > set_enabled(major, false); > - init_debug("security=%s disabled: %s\n", > + init_debug("security=%s disabled: %s (only one legacy major LSM)\n", > chosen_major_lsm, major->name); > } > } > @@ -291,7 +291,8 @@ static void __init ordered_lsm_parse(const char *order, const char *origin) > } > > if (!found) > - init_debug("%s ignored: %s\n", origin, name); > + init_debug("%s ignored: %s (not built into kernel)\n", > + origin, name); > } > > /* Process "security=", if given. */ > @@ -309,7 +310,8 @@ static void __init ordered_lsm_parse(const char *order, const char *origin) > if (exists_ordered_lsm(lsm)) > continue; > set_enabled(lsm, false); > - init_debug("%s disabled: %s\n", origin, lsm->name); > + init_debug("%s skipped: %s (not in requested order)\n", > + origin, lsm->name); > } > > kfree(sep); > @@ -320,6 +322,24 @@ static void __init lsm_early_task(struct task_struct *task); > > static int lsm_append(const char *new, char **result); > > +static void __init report_lsm_order(void) > +{ > + struct lsm_info **lsm, *early; > + int first = 0; > + > + pr_info("initializing lsm="); > + > + /* Report each enabled LSM name, comma separated. */ > + for (early = __start_early_lsm_info; early < __end_early_lsm_info; early++) > + if (is_enabled(early)) > + pr_cont("%s%s", first++ == 0 ? "" : ",", early->name); > + for (lsm = ordered_lsms; *lsm; lsm++) > + if (is_enabled(*lsm)) > + pr_cont("%s%s", first++ == 0 ? "" : ",", (*lsm)->name); > + > + pr_cont("\n"); > +} > + > static void __init ordered_lsm_init(void) > { > struct lsm_info **lsm; > @@ -329,7 +349,8 @@ static void __init ordered_lsm_init(void) > > if (chosen_lsm_order) { > if (chosen_major_lsm) { > - pr_info("security= is ignored because it is superseded by lsm=\n"); > + pr_warn("security=%s is ignored because it is superseded by lsm=%s\n", > + chosen_major_lsm, chosen_lsm_order); > chosen_major_lsm = NULL; > } > ordered_lsm_parse(chosen_lsm_order, "cmdline"); > @@ -339,6 +360,8 @@ static void __init ordered_lsm_init(void) > for (lsm = ordered_lsms; *lsm; lsm++) > prepare_lsm(*lsm); > > + report_lsm_order(); > + > init_debug("cred blob size = %d\n", blob_sizes.lbs_cred); > init_debug("file blob size = %d\n", blob_sizes.lbs_file); > init_debug("inode blob size = %d\n", blob_sizes.lbs_inode); > @@ -395,13 +418,17 @@ int __init security_init(void) > { > struct lsm_info *lsm; > > - pr_info("Security Framework initializing\n"); > + init_debug("legacy security=%s\n", chosen_major_lsm ?: " *unspecified*"); > + init_debug(" CONFIG_LSM=%s\n", builtin_lsm_order); > + init_debug("boot arg lsm=%s\n", chosen_lsm_order ?: " *unspecified*"); > > /* > * Append the names of the early LSM modules now that kmalloc() is > * available > */ > for (lsm = __start_early_lsm_info; lsm < __end_early_lsm_info; lsm++) { > + init_debug(" early started: %s (%s)\n", lsm->name, > + is_enabled(lsm) ? "enabled" : "disabled"); > if (lsm->enabled) > lsm_append(lsm->name, &lsm_names); > }
