[INSTALLED,1/2] regex: fix heap-use-after-free error
Commit Message
From: Assaf Gordon <assafgordon@gmail.com>
[BZ #18040]
Problem reported by Saito Takaaki <tails.saito@gmail.com> 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(+)
@@ -1,3 +1,16 @@
+2018-12-15 Assaf Gordon <assafgordon@gmail.com>
+
+ regex: fix heap-use-after-free error
+ [BZ #18040]
+ Problem reported by Saito Takaaki <tails.saito@gmail.com> 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 <fweimer@redhat.com>
* support/blob_repeat.c (check_mul_overflow_size_t): New function.
@@ -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;
}