diff options
Diffstat (limited to 'security/keys/keyring.c')
| -rw-r--r-- | security/keys/keyring.c | 39 |
1 files changed, 19 insertions, 20 deletions
diff --git a/security/keys/keyring.c b/security/keys/keyring.c index a7e51f793867..36f842ec87f0 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; } /* |