4.9-stable review patch. If anyone has any objections, please let me know.
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From: Ilya Dryomov idryomov@gmail.com
commit cc255c76c70f7a87d97939621eae04b600d9f4a1 upstream.
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 [bwh: Backported to 4.9: - Define and test the feature bit in the old way - Don't change any other feature bits in ceph_features.h] Signed-off-by: Ben Hutchings ben.hutchings@codethink.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/linux/ceph/ceph_features.h | 4 + net/ceph/auth_x.c | 77 +++++++++++++++++++++++++++---------- 2 files changed, 61 insertions(+), 20 deletions(-)
--- a/include/linux/ceph/ceph_features.h +++ b/include/linux/ceph/ceph_features.h @@ -76,6 +76,7 @@ // duplicated since it was introduced at the same time as CEPH_FEATURE_CRUSH_TUNABLES5 #define CEPH_FEATURE_NEW_OSDOPREPLY_ENCODING (1ULL<<58) /* New, v7 encoding */ #define CEPH_FEATURE_FS_FILE_LAYOUT_V2 (1ULL<<58) /* file_layout_t */ +#define CEPH_FEATURE_CEPHX_V2 (1ULL<<61) // *do not share this bit*
/* * The introduction of CEPH_FEATURE_OSD_SNAPMAPPER caused the feature @@ -124,7 +125,8 @@ static inline u64 ceph_sanitize_features CEPH_FEATURE_MSGR_KEEPALIVE2 | \ CEPH_FEATURE_CRUSH_V4 | \ 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 | \ --- a/net/ceph/auth_x.c +++ b/net/ceph/auth_x.c @@ -8,6 +8,7 @@
#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>
@@ -799,26 +800,64 @@ static int calc_signature(struct ceph_x_ __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; + int ret; + + if (msg->con->peer_features & CEPH_FEATURE_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; }