From patchwork Sun Dec 16 15:11:04 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Eggert X-Patchwork-Id: 30684 Received: (qmail 26927 invoked by alias); 16 Dec 2018 15:11:22 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 26531 invoked by uid 89); 16 Dec 2018 15:11:21 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-26.9 required=5.0 tests=BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, SPF_PASS autolearn=ham version=3.3.2 spammy=idx X-HELO: zimbra.cs.ucla.edu From: Paul Eggert To: libc-alpha@sourceware.org Cc: Assaf Gordon Subject: [INSTALLED 1/2] regex: fix heap-use-after-free error Date: Sun, 16 Dec 2018 07:11:04 -0800 Message-Id: <20181216151105.31863-1-eggert@cs.ucla.edu> MIME-Version: 1.0 From: Assaf Gordon [BZ #18040] Problem reported by Saito Takaaki in https://debbugs.gnu.org/32592 Call stack get_subexp->get_subexp_sub->clean_state_log_if_needed may call extend_buffers which reallocates the re_string_t internal buffer. Local variable 'buf' was not updated in such case, resulting in use-after-free. * posix/regexec.c (get_subexp): Update 'buf' after call to get_subexp_sub. --- ChangeLog | 13 +++++++++++++ posix/regexec.c | 1 + 2 files changed, 14 insertions(+) diff --git a/ChangeLog b/ChangeLog index 90e9f8f2d2..2fef13ec02 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,16 @@ +2018-12-15 Assaf Gordon + + regex: fix heap-use-after-free error + [BZ #18040] + Problem reported by Saito Takaaki in + https://debbugs.gnu.org/32592 + Call stack get_subexp->get_subexp_sub->clean_state_log_if_needed may + call extend_buffers which reallocates the re_string_t internal buffer. + Local variable 'buf' was not updated in such case, resulting in + use-after-free. + * posix/regexec.c (get_subexp): Update 'buf' after call to + get_subexp_sub. + 2018-12-15 Florian Weimer * support/blob_repeat.c (check_mul_overflow_size_t): New function. diff --git a/posix/regexec.c b/posix/regexec.c index c3e6a5b8cb..a29e8ad1ff 100644 --- a/posix/regexec.c +++ b/posix/regexec.c @@ -2783,6 +2783,7 @@ get_subexp (re_match_context_t *mctx, Idx bkref_node, Idx bkref_str_idx) return REG_ESPACE; err = get_subexp_sub (mctx, sub_top, sub_last, bkref_node, bkref_str_idx); + buf = (const char *) re_string_get_buffer (&mctx->input); if (err == REG_NOMATCH) continue; }