diff options
| -rw-r--r-- | security/keys/keyctl.c | 56 |
1 files changed, 26 insertions, 30 deletions
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c index eff88a5f5d4..4743d71e4aa 100644 --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -26,6 +26,8 @@ #include <asm/uaccess.h> #include "internal.h" +#define KEY_MAX_DESC_SIZE 4096 + static int key_get_type_from_user(char *type, const char __user *_type, unsigned len) @@ -78,7 +80,7 @@ SYSCALL_DEFINE5(add_key, const char __user *, _type, description = NULL; if (_description) { - description = strndup_user(_description, PAGE_SIZE); + description = strndup_user(_description, KEY_MAX_DESC_SIZE); if (IS_ERR(description)) { ret = PTR_ERR(description); goto error; @@ -177,7 +179,7 @@ SYSCALL_DEFINE4(request_key, const char __user *, _type, goto error; /* pull the description into kernel space */ - description = strndup_user(_description, PAGE_SIZE); + description = strndup_user(_description, KEY_MAX_DESC_SIZE); if (IS_ERR(description)) { ret = PTR_ERR(description); goto error; @@ -287,7 +289,7 @@ long keyctl_join_session_keyring(const char __user *_name) /* fetch the name from userspace */ name = NULL; if (_name) { - name = strndup_user(_name, PAGE_SIZE); + name = strndup_user(_name, KEY_MAX_DESC_SIZE); if (IS_ERR(name)) { ret = PTR_ERR(name); goto error; @@ -562,8 +564,9 @@ long keyctl_describe_key(key_serial_t keyid, { struct key *key, *instkey; key_ref_t key_ref; - char *tmpbuf; + char *infobuf; long ret; + int desclen, infolen; key_ref = lookup_user_key(keyid, KEY_LOOKUP_PARTIAL, KEY_NEED_VIEW); if (IS_ERR(key_ref)) { @@ -586,38 +589,31 @@ long keyctl_describe_key(key_serial_t keyid, } okay: - /* calculate how much description we're going to return */ - ret = -ENOMEM; - tmpbuf = kmalloc(PAGE_SIZE, GFP_KERNEL); - if (!tmpbuf) - goto error2; - key = key_ref_to_ptr(key_ref); + desclen = strlen(key->description); - ret = snprintf(tmpbuf, PAGE_SIZE - 1, - "%s;%d;%d;%08x;%s", - key->type->name, - from_kuid_munged(current_user_ns(), key->uid), - from_kgid_munged(current_user_ns(), key->gid), - key->perm, - key->description ?: ""); - - /* include a NUL char at the end of the data */ - if (ret > PAGE_SIZE - 1) - ret = PAGE_SIZE - 1; - tmpbuf[ret] = 0; - ret++; + /* calculate how much information we're going to return */ + ret = -ENOMEM; + infobuf = kasprintf(GFP_KERNEL, + "%s;%d;%d;%08x;", + key->type->name, + from_kuid_munged(current_user_ns(), key->uid), + from_kgid_munged(current_user_ns(), key->gid), + key->perm); + if (!infobuf) + goto error2; + infolen = strlen(infobuf); + ret = infolen + desclen + 1; /* consider returning the data */ - if (buffer && buflen > 0) { - if (buflen > ret) - buflen = ret; - - if (copy_to_user(buffer, tmpbuf, buflen) != 0) + if (buffer && buflen >= ret) { + if (copy_to_user(buffer, infobuf, infolen) != 0 || + copy_to_user(buffer + infolen, key->description, + desclen + 1) != 0) ret = -EFAULT; } - kfree(tmpbuf); + kfree(infobuf); error2: key_ref_put(key_ref); error: @@ -649,7 +645,7 @@ long keyctl_keyring_search(key_serial_t ringid, if (ret < 0) goto error; - description = strndup_user(_description, PAGE_SIZE); + description = strndup_user(_description, KEY_MAX_DESC_SIZE); if (IS_ERR(description)) { ret = PTR_ERR(description); goto error; |