[Precise][Trusty][CVE-2014-6416/7/8][PATCH 2/2] libceph: do not hard code max auth ticket len
Luis Henriques
luis.henriques at canonical.com
Mon Sep 22 16:10:47 UTC 2014
From: Ilya Dryomov <ilya.dryomov at inktank.com>
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 at vger.kernel.org
Signed-off-by: Ilya Dryomov <ilya.dryomov at inktank.com>
Reviewed-by: Sage Weil <sage at redhat.com>
(cherry picked from commit c27a3e4d667fdcad3db7b104f75659478e0c68d8)
CVE-2014-6416
BugLink: http://bugs.launchpad.net/bugs/1370044
CVE-2014-6417
BugLink: http://bugs.launchpad.net/bugs/1370046
CVE-2014-6418
BugLink: http://bugs.launchpad.net/bugs/1370047
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
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))
--
2.1.0
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