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authorKees Cook <keescook@chromium.org>2013-01-11 14:32:07 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-01-11 14:54:55 -0800
commit0644ec0cc8a33fb654e348897ad7684e22a4b5d8 (patch)
tree95a0532a89fdd148593c4bd52faa055d308e3380 /kernel
parent7b9205bd775afc4439ed86d617f9042ee9e76a71 (diff)
downloadlinaro-lsk-0644ec0cc8a33fb654e348897ad7684e22a4b5d8.tar.gz
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@chromium.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric Paris <eparis@redhat.com> Cc: Jeff Layton <jlayton@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Julien Tinnes <jln@google.com> Cc: Will Drewry <wad@google.com> Cc: Steve Grubb <sgrubb@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/audit.c4
-rw-r--r--kernel/audit_tree.c26
-rw-r--r--kernel/audit_watch.c2
-rw-r--r--kernel/auditsc.c6
4 files changed, 27 insertions, 11 deletions
diff --git a/kernel/audit.c b/kernel/audit.c
index 40414e9143d..a219998aecc 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -272,6 +272,8 @@ static int audit_log_config_change(char *function_name, int new, int old,
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(struct audit_buffer **ab, u16 msg_type,
}
*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 --git a/kernel/audit_tree.c b/kernel/audit_tree.c
index e81175ef25f..642a89c4f3d 100644
--- a/kernel/audit_tree.c
+++ b/kernel/audit_tree.c
@@ -449,11 +449,26 @@ static int tag_chunk(struct inode *inode, struct audit_tree *tree)
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 *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 --git a/kernel/audit_watch.c b/kernel/audit_watch.c
index 4a599f699ad..22831c4d369 100644
--- a/kernel/audit_watch.c
+++ b/kernel/audit_watch.c
@@ -240,6 +240,8 @@ static void audit_watch_log_rule_change(struct audit_krule *r, struct audit_watc
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 --git a/kernel/auditsc.c b/kernel/auditsc.c
index 3e46d1dec61..a371f857a0a 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1464,14 +1464,14 @@ static void show_special(struct audit_context *context, int *call_panic)
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);
}