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authorLinus Torvalds <torvalds@linux-foundation.org>2020-02-27 11:01:22 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-02-27 11:01:22 -0800
commited5fa5591866f95be1fe75cd267cf9df2c0390f5 (patch)
treeb483dc1440127f7617925a062dbed0cef143cbcf /kernel
parentbfdc6d91a25f4545bcd1b12e3219af4838142ef1 (diff)
parent756125289285f6e55a03861bf4b6257aa3d19a93 (diff)
Merge tag 'audit-pr-20200226' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit
Pull audit fixes from Paul Moore: "Two fixes for problems found by syzbot: - Moving audit filter structure fields into a union caused some problems in the code which populates that filter structure. We keep the union (that idea is a good one), but we are fixing the code so that it doesn't needlessly set fields in the union and mess up the error handling. - The audit_receive_msg() function wasn't validating user input as well as it should in all cases, we add the necessary checks" * tag 'audit-pr-20200226' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit: audit: always check the netlink payload length in audit_receive_msg() audit: fix error handling in audit_data_to_entry()
Diffstat (limited to 'kernel')
-rw-r--r--kernel/audit.c40
-rw-r--r--kernel/auditfilter.c71
2 files changed, 60 insertions, 51 deletions
diff --git a/kernel/audit.c b/kernel/audit.c
index 17b0d523afb3..9ddfe2aa6671 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1101,13 +1101,11 @@ static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature
audit_log_end(ab);
}
-static int audit_set_feature(struct sk_buff *skb)
+static int audit_set_feature(struct audit_features *uaf)
{
- struct audit_features *uaf;
int i;
BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > ARRAY_SIZE(audit_feature_names));
- uaf = nlmsg_data(nlmsg_hdr(skb));
/* if there is ever a version 2 we should handle that here */
@@ -1175,6 +1173,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
{
u32 seq;
void *data;
+ int data_len;
int err;
struct audit_buffer *ab;
u16 msg_type = nlh->nlmsg_type;
@@ -1188,6 +1187,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
seq = nlh->nlmsg_seq;
data = nlmsg_data(nlh);
+ data_len = nlmsg_len(nlh);
switch (msg_type) {
case AUDIT_GET: {
@@ -1211,7 +1211,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
struct audit_status s;
memset(&s, 0, sizeof(s));
/* guard against past and future API changes */
- memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh)));
+ memcpy(&s, data, min_t(size_t, sizeof(s), data_len));
if (s.mask & AUDIT_STATUS_ENABLED) {
err = audit_set_enabled(s.enabled);
if (err < 0)
@@ -1315,7 +1315,9 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
return err;
break;
case AUDIT_SET_FEATURE:
- err = audit_set_feature(skb);
+ if (data_len < sizeof(struct audit_features))
+ return -EINVAL;
+ err = audit_set_feature(data);
if (err)
return err;
break;
@@ -1327,6 +1329,8 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
err = audit_filter(msg_type, AUDIT_FILTER_USER);
if (err == 1) { /* match or error */
+ char *str = data;
+
err = 0;
if (msg_type == AUDIT_USER_TTY) {
err = tty_audit_push();
@@ -1334,26 +1338,24 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
break;
}
audit_log_user_recv_msg(&ab, msg_type);
- if (msg_type != AUDIT_USER_TTY)
+ if (msg_type != AUDIT_USER_TTY) {
+ /* ensure NULL termination */
+ str[data_len - 1] = '\0';
audit_log_format(ab, " msg='%.*s'",
AUDIT_MESSAGE_TEXT_MAX,
- (char *)data);
- else {
- int size;
-
+ str);
+ } else {
audit_log_format(ab, " data=");
- size = nlmsg_len(nlh);
- if (size > 0 &&
- ((unsigned char *)data)[size - 1] == '\0')
- size--;
- audit_log_n_untrustedstring(ab, data, size);
+ if (data_len > 0 && str[data_len - 1] == '\0')
+ data_len--;
+ audit_log_n_untrustedstring(ab, str, data_len);
}
audit_log_end(ab);
}
break;
case AUDIT_ADD_RULE:
case AUDIT_DEL_RULE:
- if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
+ if (data_len < sizeof(struct audit_rule_data))
return -EINVAL;
if (audit_enabled == AUDIT_LOCKED) {
audit_log_common_recv_msg(audit_context(), &ab,
@@ -1365,7 +1367,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
audit_log_end(ab);
return -EPERM;
}
- err = audit_rule_change(msg_type, seq, data, nlmsg_len(nlh));
+ err = audit_rule_change(msg_type, seq, data, data_len);
break;
case AUDIT_LIST_RULES:
err = audit_list_rules_send(skb, seq);
@@ -1380,7 +1382,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
case AUDIT_MAKE_EQUIV: {
void *bufp = data;
u32 sizes[2];
- size_t msglen = nlmsg_len(nlh);
+ size_t msglen = data_len;
char *old, *new;
err = -EINVAL;
@@ -1456,7 +1458,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
memset(&s, 0, sizeof(s));
/* guard against past and future API changes */
- memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh)));
+ memcpy(&s, data, min_t(size_t, sizeof(s), data_len));
/* check if new data is valid */
if ((s.enabled != 0 && s.enabled != 1) ||
(s.log_passwd != 0 && s.log_passwd != 1))
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index b0126e9c0743..026e34da4ace 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -456,6 +456,7 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
bufp = data->buf;
for (i = 0; i < data->field_count; i++) {
struct audit_field *f = &entry->rule.fields[i];
+ u32 f_val;
err = -EINVAL;
@@ -464,12 +465,12 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
goto exit_free;
f->type = data->fields[i];
- f->val = data->values[i];
+ f_val = data->values[i];
/* Support legacy tests for a valid loginuid */
- if ((f->type == AUDIT_LOGINUID) && (f->val == AUDIT_UID_UNSET)) {
+ if ((f->type == AUDIT_LOGINUID) && (f_val == AUDIT_UID_UNSET)) {
f->type = AUDIT_LOGINUID_SET;
- f->val = 0;
+ f_val = 0;
entry->rule.pflags |= AUDIT_LOGINUID_LEGACY;
}
@@ -485,7 +486,7 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
case AUDIT_SUID:
case AUDIT_FSUID:
case AUDIT_OBJ_UID:
- f->uid = make_kuid(current_user_ns(), f->val);
+ f->uid = make_kuid(current_user_ns(), f_val);
if (!uid_valid(f->uid))
goto exit_free;
break;
@@ -494,11 +495,12 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
case AUDIT_SGID:
case AUDIT_FSGID:
case AUDIT_OBJ_GID:
- f->gid = make_kgid(current_user_ns(), f->val);
+ f->gid = make_kgid(current_user_ns(), f_val);
if (!gid_valid(f->gid))
goto exit_free;
break;
case AUDIT_ARCH:
+ f->val = f_val;
entry->rule.arch_f = f;
break;
case AUDIT_SUBJ_USER:
@@ -511,11 +513,13 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
case AUDIT_OBJ_TYPE:
case AUDIT_OBJ_LEV_LOW:
case AUDIT_OBJ_LEV_HIGH:
- str = audit_unpack_string(&bufp, &remain, f->val);
- if (IS_ERR(str))
+ str = audit_unpack_string(&bufp, &remain, f_val);
+ if (IS_ERR(str)) {
+ err = PTR_ERR(str);
goto exit_free;
- entry->rule.buflen += f->val;
-
+ }
+ entry->rule.buflen += f_val;
+ f->lsm_str = str;
err = security_audit_rule_init(f->type, f->op, str,
(void **)&f->lsm_rule);
/* Keep currently invalid fields around in case they
@@ -524,68 +528,71 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
pr_warn("audit rule for LSM \'%s\' is invalid\n",
str);
err = 0;
- }
- if (err) {
- kfree(str);
+ } else if (err)
goto exit_free;
- } else
- f->lsm_str = str;
break;
case AUDIT_WATCH:
- str = audit_unpack_string(&bufp, &remain, f->val);
- if (IS_ERR(str))
+ str = audit_unpack_string(&bufp, &remain, f_val);
+ if (IS_ERR(str)) {
+ err = PTR_ERR(str);
goto exit_free;
- entry->rule.buflen += f->val;
-
- err = audit_to_watch(&entry->rule, str, f->val, f->op);
+ }
+ err = audit_to_watch(&entry->rule, str, f_val, f->op);
if (err) {
kfree(str);
goto exit_free;
}
+ entry->rule.buflen += f_val;
break;
case AUDIT_DIR:
- str = audit_unpack_string(&bufp, &remain, f->val);
- if (IS_ERR(str))
+ str = audit_unpack_string(&bufp, &remain, f_val);
+ if (IS_ERR(str)) {
+ err = PTR_ERR(str);
goto exit_free;
- entry->rule.buflen += f->val;
-
+ }
err = audit_make_tree(&entry->rule, str, f->op);
kfree(str);
if (err)
goto exit_free;
+ entry->rule.buflen += f_val;
break;
case AUDIT_INODE:
+ f->val = f_val;
err = audit_to_inode(&entry->rule, f);
if (err)
goto exit_free;
break;
case AUDIT_FILTERKEY:
- if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
+ if (entry->rule.filterkey || f_val > AUDIT_MAX_KEY_LEN)
goto exit_free;
- str = audit_unpack_string(&bufp, &remain, f->val);
- if (IS_ERR(str))
+ str = audit_unpack_string(&bufp, &remain, f_val);
+ if (IS_ERR(str)) {
+ err = PTR_ERR(str);
goto exit_free;
- entry->rule.buflen += f->val;
+ }
+ entry->rule.buflen += f_val;
entry->rule.filterkey = str;
break;
case AUDIT_EXE:
- if (entry->rule.exe || f->val > PATH_MAX)
+ if (entry->rule.exe || f_val > PATH_MAX)
goto exit_free;
- str = audit_unpack_string(&bufp, &remain, f->val);
+ str = audit_unpack_string(&bufp, &remain, f_val);
if (IS_ERR(str)) {
err = PTR_ERR(str);
goto exit_free;
}
- entry->rule.buflen += f->val;
-
- audit_mark = audit_alloc_mark(&entry->rule, str, f->val);
+ audit_mark = audit_alloc_mark(&entry->rule, str, f_val);
if (IS_ERR(audit_mark)) {
kfree(str);
err = PTR_ERR(audit_mark);
goto exit_free;
}
+ entry->rule.buflen += f_val;
entry->rule.exe = audit_mark;
break;
+ default:
+ f->val = f_val;
+ break;
}
}