We hard code cephx auth ticket buffer size to 256 bytes. This isn't enough for any moderate setups and, in case tickets themselves are not encrypted, leads to buffer overflows (ceph_x_decrypt() errors out, but ceph_decode_copy() doesn't - it's just a memcpy() wrapper). Since the buffer is allocated dynamically anyway, allocated it a bit later, at the point where we know how much is going to be needed. Fixes: http://tracker.ceph.com/issues/8979 Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Ilya Dryomov <ilya.dryomov@xxxxxxxxxxx> --- net/ceph/auth_x.c | 64 ++++++++++++++++++++++++----------------------------- 1 file changed, 29 insertions(+), 35 deletions(-) diff --git a/net/ceph/auth_x.c b/net/ceph/auth_x.c index 0eb146dce1aa..de6662b14e1f 100644 --- a/net/ceph/auth_x.c +++ b/net/ceph/auth_x.c @@ -13,8 +13,6 @@ #include "auth_x.h" #include "auth_x_protocol.h" -#define TEMP_TICKET_BUF_LEN 256 - static void ceph_x_validate_tickets(struct ceph_auth_client *ac, int *pneed); static int ceph_x_is_authenticated(struct ceph_auth_client *ac) @@ -64,7 +62,7 @@ static int ceph_x_encrypt(struct ceph_crypto_key *secret, } static int ceph_x_decrypt(struct ceph_crypto_key *secret, - void **p, void *end, void *obuf, size_t olen) + void **p, void *end, void **obuf, size_t olen) { struct ceph_x_encrypt_header head; size_t head_len = sizeof(head); @@ -75,8 +73,14 @@ static int ceph_x_decrypt(struct ceph_crypto_key *secret, return -EINVAL; dout("ceph_x_decrypt len %d\n", len); - ret = ceph_decrypt2(secret, &head, &head_len, obuf, &olen, - *p, len); + if (*obuf == NULL) { + *obuf = kmalloc(len, GFP_NOFS); + if (!*obuf) + return -ENOMEM; + olen = len; + } + + ret = ceph_decrypt2(secret, &head, &head_len, *obuf, &olen, *p, len); if (ret) return ret; if (head.struct_v != 1 || le64_to_cpu(head.magic) != CEPHX_ENC_MAGIC) @@ -131,18 +135,19 @@ static void remove_ticket_handler(struct ceph_auth_client *ac, static int process_one_ticket(struct ceph_auth_client *ac, struct ceph_crypto_key *secret, - void **p, void *end, - void *dbuf, void *ticket_buf) + void **p, void *end) { struct ceph_x_info *xi = ac->private; int type; u8 tkt_struct_v, blob_struct_v; struct ceph_x_ticket_handler *th; + void *dbuf = NULL; void *dp, *dend; int dlen; char is_enc; struct timespec validity; struct ceph_crypto_key old_key; + void *ticket_buf = NULL; void *tp, *tpend; struct ceph_timespec new_validity; struct ceph_crypto_key new_session_key; @@ -167,8 +172,7 @@ static int process_one_ticket(struct ceph_auth_client *ac, } /* blob for me */ - dlen = ceph_x_decrypt(secret, p, end, dbuf, - TEMP_TICKET_BUF_LEN); + dlen = ceph_x_decrypt(secret, p, end, &dbuf, 0); if (dlen <= 0) { ret = dlen; goto out; @@ -195,20 +199,25 @@ static int process_one_ticket(struct ceph_auth_client *ac, /* ticket blob for service */ ceph_decode_8_safe(p, end, is_enc, bad); - tp = ticket_buf; if (is_enc) { /* encrypted */ dout(" encrypted ticket\n"); - dlen = ceph_x_decrypt(&old_key, p, end, ticket_buf, - TEMP_TICKET_BUF_LEN); + dlen = ceph_x_decrypt(&old_key, p, end, &ticket_buf, 0); if (dlen < 0) { ret = dlen; goto out; } + tp = ticket_buf; dlen = ceph_decode_32(&tp); } else { /* unencrypted */ ceph_decode_32_safe(p, end, dlen, bad); + ticket_buf = kmalloc(dlen, GFP_NOFS); + if (!ticket_buf) { + ret = -ENOMEM; + goto out; + } + tp = ticket_buf; ceph_decode_need(p, end, dlen, bad); ceph_decode_copy(p, ticket_buf, dlen); } @@ -237,6 +246,8 @@ static int process_one_ticket(struct ceph_auth_client *ac, xi->have_keys |= th->service; out: + kfree(ticket_buf); + kfree(dbuf); return ret; bad: @@ -249,21 +260,10 @@ static int ceph_x_proc_ticket_reply(struct ceph_auth_client *ac, void *buf, void *end) { void *p = buf; - char *dbuf; - char *ticket_buf; u8 reply_struct_v; u32 num; int ret; - dbuf = kmalloc(TEMP_TICKET_BUF_LEN, GFP_NOFS); - if (!dbuf) - return -ENOMEM; - - ret = -ENOMEM; - ticket_buf = kmalloc(TEMP_TICKET_BUF_LEN, GFP_NOFS); - if (!ticket_buf) - goto out_dbuf; - ceph_decode_8_safe(&p, end, reply_struct_v, bad); if (reply_struct_v != 1) return -EINVAL; @@ -272,22 +272,15 @@ static int ceph_x_proc_ticket_reply(struct ceph_auth_client *ac, dout("%d tickets\n", num); while (num--) { - ret = process_one_ticket(ac, secret, &p, end, - dbuf, ticket_buf); + ret = process_one_ticket(ac, secret, &p, end); if (ret) - goto out; + return ret; } - ret = 0; -out: - kfree(ticket_buf); -out_dbuf: - kfree(dbuf); - return ret; + return 0; bad: - ret = -EINVAL; - goto out; + return -EINVAL; } static int ceph_x_build_authorizer(struct ceph_auth_client *ac, @@ -603,13 +596,14 @@ static int ceph_x_verify_authorizer_reply(struct ceph_auth_client *ac, struct ceph_x_ticket_handler *th; int ret = 0; struct ceph_x_authorize_reply reply; + void *preply = &reply; void *p = au->reply_buf; void *end = p + sizeof(au->reply_buf); th = get_ticket_handler(ac, au->service); if (IS_ERR(th)) return PTR_ERR(th); - ret = ceph_x_decrypt(&th->session_key, &p, end, &reply, sizeof(reply)); + ret = ceph_x_decrypt(&th->session_key, &p, end, &preply, sizeof(reply)); if (ret < 0) return ret; if (ret != sizeof(reply)) -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
