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| author | Daiki Ueno <ueno@gnu.org> | 2021-04-04 09:40:35 +0000 |
|---|---|---|
| committer | Daiki Ueno <ueno@gnu.org> | 2021-04-04 09:40:35 +0000 |
| commit | 1bd5c9c7a2b87b7c7ec802f83b1480de388a3a09 (patch) | |
| tree | 5ec3806a5a9cb2213d6340f31962539eaa6fc60a /lib/ext/key_share.c | |
| parent | 5980d0d9a23b552703507625ba6437bca7f45005 (diff) | |
| parent | dc07b8228b4bab83af5bcf7a2efd9d2a0f10f628 (diff) | |
| download | gnutls-1bd5c9c7a2b87b7c7ec802f83b1480de388a3a09.tar.gz | |
Merge branch 'wip/dueno/realloc-3.6.x' into 'gnutls_3_6_x'
key_share, pre_shared_key: avoid use-after-free around realloc [3.6.x]
See merge request gnutls/gnutls!1408
Diffstat (limited to 'lib/ext/key_share.c')
| -rw-r--r-- | lib/ext/key_share.c | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/lib/ext/key_share.c b/lib/ext/key_share.c index ab8abf8fe6..a8c4bb5cff 100644 --- a/lib/ext/key_share.c +++ b/lib/ext/key_share.c @@ -664,14 +664,14 @@ key_share_send_params(gnutls_session_t session, { unsigned i; int ret; - unsigned char *lengthp; - unsigned int cur_length; unsigned int generated = 0; const gnutls_group_entry_st *group; const version_entry_st *ver; /* this extension is only being sent on client side */ if (session->security_parameters.entity == GNUTLS_CLIENT) { + unsigned int length_pos; + ver = _gnutls_version_max(session); if (unlikely(ver == NULL || ver->key_shares == 0)) return 0; @@ -679,16 +679,13 @@ key_share_send_params(gnutls_session_t session, if (!have_creds_for_tls13(session)) return 0; - /* write the total length later */ - lengthp = &extdata->data[extdata->length]; + length_pos = extdata->length; ret = _gnutls_buffer_append_prefix(extdata, 16, 0); if (ret < 0) return gnutls_assert_val(ret); - cur_length = extdata->length; - if (session->internals.hsk_flags & HSK_HRR_RECEIVED) { /* we know the group */ group = get_group(session); if (unlikely(group == NULL)) @@ -736,7 +733,8 @@ key_share_send_params(gnutls_session_t session, } /* copy actual length */ - _gnutls_write_uint16(extdata->length - cur_length, lengthp); + _gnutls_write_uint16(extdata->length - length_pos - 2, + &extdata->data[length_pos]); } else { /* server */ ver = get_version(session); |