From 077caf61d867d4cab49b5aa42da1611868596fe7 Mon Sep 17 00:00:00 2001 From: Assaf Gordon Date: Wed, 5 Sep 2018 23:25:07 -0700 Subject: [PATCH] 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. --- 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; } -- 2.43.5