libceph: implement CEPHX_V2 calculation mode

Derive the signature from the entire buffer (both AES cipher blocks)
instead of using just the first half of the first block, leaving out
data_crc entirely.

This addresses CVE-2018-1129.

Link: http://tracker.ceph.com/issues/24837
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>
This commit is contained in:
Ilya Dryomov 2018-07-27 19:25:32 +02:00
parent 6daca13d2e
commit cc255c76c7
2 changed files with 60 additions and 20 deletions

View File

@ -165,9 +165,9 @@ DEFINE_CEPH_FEATURE(58, 1, FS_FILE_LAYOUT_V2) // overlap
DEFINE_CEPH_FEATURE(59, 1, FS_BTIME)
DEFINE_CEPH_FEATURE(59, 1, FS_CHANGE_ATTR) // overlap
DEFINE_CEPH_FEATURE(59, 1, MSG_ADDR2) // overlap
DEFINE_CEPH_FEATURE(60, 1, BLKIN_TRACING) // *do not share this bit*
DEFINE_CEPH_FEATURE(60, 1, OSD_RECOVERY_DELETES) // *do not share this bit*
DEFINE_CEPH_FEATURE(61, 1, CEPHX_V2) // *do not share this bit*
DEFINE_CEPH_FEATURE(61, 1, RESERVED2) // unused, but slow down!
DEFINE_CEPH_FEATURE(62, 1, RESERVED) // do not use; used as a sentinal
DEFINE_CEPH_FEATURE_DEPRECATED(63, 1, RESERVED_BROKEN, LUMINOUS) // client-facing
@ -210,7 +210,8 @@ DEFINE_CEPH_FEATURE_DEPRECATED(63, 1, RESERVED_BROKEN, LUMINOUS) // client-facin
CEPH_FEATURE_SERVER_JEWEL | \
CEPH_FEATURE_MON_STATEFUL_SUB | \
CEPH_FEATURE_CRUSH_TUNABLES5 | \
CEPH_FEATURE_NEW_OSDOPREPLY_ENCODING)
CEPH_FEATURE_NEW_OSDOPREPLY_ENCODING | \
CEPH_FEATURE_CEPHX_V2)
#define CEPH_FEATURES_REQUIRED_DEFAULT \
(CEPH_FEATURE_NOSRCADDR | \

View File

@ -9,6 +9,7 @@
#include <linux/ceph/decode.h>
#include <linux/ceph/auth.h>
#include <linux/ceph/ceph_features.h>
#include <linux/ceph/libceph.h>
#include <linux/ceph/messenger.h>
@ -803,26 +804,64 @@ static int calc_signature(struct ceph_x_authorizer *au, struct ceph_msg *msg,
__le64 *psig)
{
void *enc_buf = au->enc_buf;
struct {
__le32 len;
__le32 header_crc;
__le32 front_crc;
__le32 middle_crc;
__le32 data_crc;
} __packed *sigblock = enc_buf + ceph_x_encrypt_offset();
int ret;
sigblock->len = cpu_to_le32(4*sizeof(u32));
sigblock->header_crc = msg->hdr.crc;
sigblock->front_crc = msg->footer.front_crc;
sigblock->middle_crc = msg->footer.middle_crc;
sigblock->data_crc = msg->footer.data_crc;
ret = ceph_x_encrypt(&au->session_key, enc_buf, CEPHX_AU_ENC_BUF_LEN,
sizeof(*sigblock));
if (ret < 0)
return ret;
if (!CEPH_HAVE_FEATURE(msg->con->peer_features, CEPHX_V2)) {
struct {
__le32 len;
__le32 header_crc;
__le32 front_crc;
__le32 middle_crc;
__le32 data_crc;
} __packed *sigblock = enc_buf + ceph_x_encrypt_offset();
sigblock->len = cpu_to_le32(4*sizeof(u32));
sigblock->header_crc = msg->hdr.crc;
sigblock->front_crc = msg->footer.front_crc;
sigblock->middle_crc = msg->footer.middle_crc;
sigblock->data_crc = msg->footer.data_crc;
ret = ceph_x_encrypt(&au->session_key, enc_buf,
CEPHX_AU_ENC_BUF_LEN, sizeof(*sigblock));
if (ret < 0)
return ret;
*psig = *(__le64 *)(enc_buf + sizeof(u32));
} else {
struct {
__le32 header_crc;
__le32 front_crc;
__le32 front_len;
__le32 middle_crc;
__le32 middle_len;
__le32 data_crc;
__le32 data_len;
__le32 seq_lower_word;
} __packed *sigblock = enc_buf;
struct {
__le64 a, b, c, d;
} __packed *penc = enc_buf;
int ciphertext_len;
sigblock->header_crc = msg->hdr.crc;
sigblock->front_crc = msg->footer.front_crc;
sigblock->front_len = msg->hdr.front_len;
sigblock->middle_crc = msg->footer.middle_crc;
sigblock->middle_len = msg->hdr.middle_len;
sigblock->data_crc = msg->footer.data_crc;
sigblock->data_len = msg->hdr.data_len;
sigblock->seq_lower_word = *(__le32 *)&msg->hdr.seq;
/* no leading len, no ceph_x_encrypt_header */
ret = ceph_crypt(&au->session_key, true, enc_buf,
CEPHX_AU_ENC_BUF_LEN, sizeof(*sigblock),
&ciphertext_len);
if (ret)
return ret;
*psig = penc->a ^ penc->b ^ penc->c ^ penc->d;
}
*psig = *(__le64 *)(enc_buf + sizeof(u32));
return 0;
}