Merge branch 'fixes-v4.14-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull key handling fixes from James Morris:
"Fixes for the Keys subsystem by Eric Biggers"
* 'fixes-v4.14-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
KEYS: fix out-of-bounds read during ASN.1 parsing
KEYS: trusted: fix writing past end of buffer in trusted_read()
KEYS: return full count in keyring_read() if buffer is too small
diff --git a/lib/asn1_decoder.c b/lib/asn1_decoder.c
index 0bd8a61..fef5d2e 100644
--- a/lib/asn1_decoder.c
+++ b/lib/asn1_decoder.c
@@ -284,6 +284,9 @@ int asn1_ber_decoder(const struct asn1_decoder *decoder,
if (unlikely(len > datalen - dp))
goto data_overrun_error;
}
+ } else {
+ if (unlikely(len > datalen - dp))
+ goto data_overrun_error;
}
if (flags & FLAG_CONS) {
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index a7e51f7..36f842e 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -459,34 +459,33 @@ static long keyring_read(const struct key *keyring,
char __user *buffer, size_t buflen)
{
struct keyring_read_iterator_context ctx;
- unsigned long nr_keys;
- int ret;
+ long ret;
kenter("{%d},,%zu", key_serial(keyring), buflen);
if (buflen & (sizeof(key_serial_t) - 1))
return -EINVAL;
- nr_keys = keyring->keys.nr_leaves_on_tree;
- if (nr_keys == 0)
- return 0;
-
- /* Calculate how much data we could return */
- if (!buffer || !buflen)
- return nr_keys * sizeof(key_serial_t);
-
- /* Copy the IDs of the subscribed keys into the buffer */
- ctx.buffer = (key_serial_t __user *)buffer;
- ctx.buflen = buflen;
- ctx.count = 0;
- ret = assoc_array_iterate(&keyring->keys, keyring_read_iterator, &ctx);
- if (ret < 0) {
- kleave(" = %d [iterate]", ret);
- return ret;
+ /* Copy as many key IDs as fit into the buffer */
+ if (buffer && buflen) {
+ ctx.buffer = (key_serial_t __user *)buffer;
+ ctx.buflen = buflen;
+ ctx.count = 0;
+ ret = assoc_array_iterate(&keyring->keys,
+ keyring_read_iterator, &ctx);
+ if (ret < 0) {
+ kleave(" = %ld [iterate]", ret);
+ return ret;
+ }
}
- kleave(" = %zu [ok]", ctx.count);
- return ctx.count;
+ /* Return the size of the buffer needed */
+ ret = keyring->keys.nr_leaves_on_tree * sizeof(key_serial_t);
+ if (ret <= buflen)
+ kleave("= %ld [ok]", ret);
+ else
+ kleave("= %ld [buffer too small]", ret);
+ return ret;
}
/*
diff --git a/security/keys/trusted.c b/security/keys/trusted.c
index bd85315..98aa89f 100644
--- a/security/keys/trusted.c
+++ b/security/keys/trusted.c
@@ -1147,20 +1147,21 @@ static long trusted_read(const struct key *key, char __user *buffer,
p = dereference_key_locked(key);
if (!p)
return -EINVAL;
- if (!buffer || buflen <= 0)
- return 2 * p->blob_len;
- ascii_buf = kmalloc(2 * p->blob_len, GFP_KERNEL);
- if (!ascii_buf)
- return -ENOMEM;
- bufp = ascii_buf;
- for (i = 0; i < p->blob_len; i++)
- bufp = hex_byte_pack(bufp, p->blob[i]);
- if ((copy_to_user(buffer, ascii_buf, 2 * p->blob_len)) != 0) {
+ if (buffer && buflen >= 2 * p->blob_len) {
+ ascii_buf = kmalloc(2 * p->blob_len, GFP_KERNEL);
+ if (!ascii_buf)
+ return -ENOMEM;
+
+ bufp = ascii_buf;
+ for (i = 0; i < p->blob_len; i++)
+ bufp = hex_byte_pack(bufp, p->blob[i]);
+ if (copy_to_user(buffer, ascii_buf, 2 * p->blob_len) != 0) {
+ kzfree(ascii_buf);
+ return -EFAULT;
+ }
kzfree(ascii_buf);
- return -EFAULT;
}
- kzfree(ascii_buf);
return 2 * p->blob_len;
}
