From 75a937d97f4fefc6f9b08e3791f151445f551cb3 Mon Sep 17 00:00:00 2001 From: Daiki Ueno Date: Fri, 29 Jan 2021 14:06:50 +0100 Subject: [PATCH] pre_shared_key: avoid use-after-free around realloc Signed-off-by: Daiki Ueno https://gitlab.com/gnutls/gnutls/-/commit/75a937d97f4fefc6f9b08e3791f151445f551cb3 Upstream-Status: Backport CVE: CVE-2021-CVE-2021-20232 Signed-off-by: Chee Yang Lee --- lib/ext/pre_shared_key.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/lib/ext/pre_shared_key.c b/lib/ext/pre_shared_key.c index a042c6488e..380bf39ed5 100644 --- a/lib/ext/pre_shared_key.c +++ b/lib/ext/pre_shared_key.c @@ -267,7 +267,7 @@ client_send_params(gnutls_session_t session, size_t spos; gnutls_datum_t username = {NULL, 0}; gnutls_datum_t user_key = {NULL, 0}, rkey = {NULL, 0}; - gnutls_datum_t client_hello; + unsigned client_hello_len; unsigned next_idx; const mac_entry_st *prf_res = NULL; const mac_entry_st *prf_psk = NULL; @@ -428,8 +428,7 @@ client_send_params(gnutls_session_t session, assert(extdata->length >= sizeof(mbuffer_st)); assert(ext_offset >= (ssize_t)sizeof(mbuffer_st)); ext_offset -= sizeof(mbuffer_st); - client_hello.data = extdata->data+sizeof(mbuffer_st); - client_hello.size = extdata->length-sizeof(mbuffer_st); + client_hello_len = extdata->length-sizeof(mbuffer_st); next_idx = 0; @@ -440,6 +439,11 @@ client_send_params(gnutls_session_t session, } if (prf_res && rkey.size > 0) { + gnutls_datum_t client_hello; + + client_hello.data = extdata->data+sizeof(mbuffer_st); + client_hello.size = client_hello_len; + ret = compute_psk_binder(session, prf_res, binders_len, binders_pos, ext_offset, &rkey, &client_hello, 1, @@ -474,6 +478,11 @@ client_send_params(gnutls_session_t session, } if (prf_psk && user_key.size > 0 && info) { + gnutls_datum_t client_hello; + + client_hello.data = extdata->data+sizeof(mbuffer_st); + client_hello.size = client_hello_len; + ret = compute_psk_binder(session, prf_psk, binders_len, binders_pos, ext_offset, &user_key, &client_hello, 0, -- GitLab