The patch titled
Subject: audit: catch possible NULL audit buffers
has been added to the -mm tree. Its filename is
audit-catch-possible-null-audit-buffers.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Kees Cook <keescook@xxxxxxxxxxxx>
Subject: audit: catch possible NULL audit buffers
It's possible for audit_log_start() to return NULL. Handle it in the
various callers.
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Eric Paris <eparis@xxxxxxxxxx>
Cc: Jeff Layton <jlayton@xxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Julien Tinnes <jln@xxxxxxxxxx>
Cc: Will Drewry <wad@xxxxxxxxxx>
Cc: Steve Grubb <sgrubb@xxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/audit.c | 4 ++++
kernel/audit_tree.c | 26 +++++++++++++++++---------
kernel/audit_watch.c | 2 ++
kernel/auditsc.c | 6 ++++--
4 files changed, 27 insertions(+), 11 deletions(-)
diff -puN kernel/audit.c~audit-catch-possible-null-audit-buffers kernel/audit.c
--- a/kernel/audit.c~audit-catch-possible-null-audit-buffers
+++ a/kernel/audit.c
@@ -272,6 +272,8 @@ static int audit_log_config_change(char
int rc = 0;
ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
+ if (unlikely(!ab))
+ return rc;
audit_log_format(ab, "%s=%d old=%d auid=%u ses=%u", function_name, new,
old, from_kuid(&init_user_ns, loginuid), sessionid);
if (sid) {
@@ -619,6 +621,8 @@ static int audit_log_common_recv_msg(str
}
*ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
+ if (unlikely(!*ab))
+ return rc;
audit_log_format(*ab, "pid=%d uid=%u auid=%u ses=%u",
task_tgid_vnr(current),
from_kuid(&init_user_ns, current_uid()),
diff -puN kernel/audit_tree.c~audit-catch-possible-null-audit-buffers kernel/audit_tree.c
--- a/kernel/audit_tree.c~audit-catch-possible-null-audit-buffers
+++ a/kernel/audit_tree.c
@@ -449,11 +449,26 @@ static int tag_chunk(struct inode *inode
return 0;
}
+static void audit_log_remove_rule(struct audit_krule *rule)
+{
+ struct audit_buffer *ab;
+
+ ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
+ if (unlikely(!ab))
+ return;
+ audit_log_format(ab, "op=");
+ audit_log_string(ab, "remove rule");
+ audit_log_format(ab, " dir=");
+ audit_log_untrustedstring(ab, rule->tree->pathname);
+ audit_log_key(ab, rule->filterkey);
+ audit_log_format(ab, " list=%d res=1", rule->listnr);
+ audit_log_end(ab);
+}
+
static void kill_rules(struct audit_tree *tree)
{
struct audit_krule *rule, *next;
struct audit_entry *entry;
- struct audit_buffer *ab;
list_for_each_entry_safe(rule, next, &tree->rules, rlist) {
entry = container_of(rule, struct audit_entry, rule);
@@ -461,14 +476,7 @@ static void kill_rules(struct audit_tree
list_del_init(&rule->rlist);
if (rule->tree) {
/* not a half-baked one */
- ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
- audit_log_format(ab, "op=");
- audit_log_string(ab, "remove rule");
- audit_log_format(ab, " dir=");
- audit_log_untrustedstring(ab, rule->tree->pathname);
- audit_log_key(ab, rule->filterkey);
- audit_log_format(ab, " list=%d res=1", rule->listnr);
- audit_log_end(ab);
+ audit_log_remove_rule(rule);
rule->tree = NULL;
list_del_rcu(&entry->list);
list_del(&entry->rule.list);
diff -puN kernel/audit_watch.c~audit-catch-possible-null-audit-buffers kernel/audit_watch.c
--- a/kernel/audit_watch.c~audit-catch-possible-null-audit-buffers
+++ a/kernel/audit_watch.c
@@ -240,6 +240,8 @@ static void audit_watch_log_rule_change(
if (audit_enabled) {
struct audit_buffer *ab;
ab = audit_log_start(NULL, GFP_NOFS, AUDIT_CONFIG_CHANGE);
+ if (unlikely(!ab))
+ return;
audit_log_format(ab, "auid=%u ses=%u op=",
from_kuid(&init_user_ns, audit_get_loginuid(current)),
audit_get_sessionid(current));
diff -puN kernel/auditsc.c~audit-catch-possible-null-audit-buffers kernel/auditsc.c
--- a/kernel/auditsc.c~audit-catch-possible-null-audit-buffers
+++ a/kernel/auditsc.c
@@ -1464,14 +1464,14 @@ static void show_special(struct audit_co
audit_log_end(ab);
ab = audit_log_start(context, GFP_KERNEL,
AUDIT_IPC_SET_PERM);
+ if (unlikely(!ab))
+ return;
audit_log_format(ab,
"qbytes=%lx ouid=%u ogid=%u mode=%#ho",
context->ipc.qbytes,
context->ipc.perm_uid,
context->ipc.perm_gid,
context->ipc.perm_mode);
- if (!ab)
- return;
}
break; }
case AUDIT_MQ_OPEN: {
@@ -2720,6 +2720,8 @@ void audit_core_dumps(long signr)
return;
ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_ANOM_ABEND);
+ if (unlikely(!ab))
+ return;
audit_log_abend(ab, "memory violation", signr);
audit_log_end(ab);
}
_
Patches currently in -mm which might be from keescook@xxxxxxxxxxxx are
linux-next.patch
audit-create-explicit-audit_seccomp-event-type.patch
audit-catch-possible-null-audit-buffers.patch
fs-pstore-ramc-fix-up-section-annotations.patch
checkpatch-warn-about-using-config_experimental.patch
binfmt_elfc-use-get_random_int-to-fix-entropy-depleting.patch
proc-dont-show-nonexistent-capabilities.patch
proc-pid-status-add-seccomp-field.patch
proc-pid-status-show-all-supplementary-groups.patch
exec-do-not-leave-bprm-interp-on-stack.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
