diff mbox series

[v2] grep: work around UTF-8 related JIT bug in PCRE2 <= 10.34

Message ID 20230323172539.25230-1-minipli@grsecurity.net (mailing list archive)
State Accepted
Commit 14b9a044798ebb3858a1f1a1377309a3d6054ac8
Headers show
Series [v2] grep: work around UTF-8 related JIT bug in PCRE2 <= 10.34 | expand

Commit Message

Mathias Krause March 23, 2023, 5:25 p.m. UTC 
Stephane is reporting[1] a regression introduced in git v2.40.0 that leads
to 'git grep' segfaulting in his CI pipeline. It turns out, he's using an
older version of libpcre2 that triggers a wild pointer dereference in
the generated JIT code that was fixed in PCRE2 10.35.

Instead of completely disabling the JIT compiler for the buggy version,
just mask out the Unicode property handling as we used to do prior to
commit acabd2048ee0 ("grep: correctly identify utf-8 characters with
\{b,w} in -P").

[1] https://lore.kernel.org/git/7E83DAA1-F9A9-4151-8D07-D80EA6D59EEA@clumio.com/

Reported-by: Stephane Odul <stephane@clumio.com>
Signed-off-by: Mathias Krause <minipli@grsecurity.net>
---
v2:
- make PCRE2_UCP masking depend only on the PCRE2 version, as
  suggested by Junio

 grep.c | 9 +++++++++
 grep.h | 3 +++
 2 files changed, 12 insertions(+)
diff mbox series

Patch

diff --git a/grep.c b/grep.c
index cee44a78d044..dcfa7a27bf88 100644
--- a/grep.c
+++ b/grep.c
@@ -320,6 +320,15 @@  static void compile_pcre2_pattern(struct grep_pat *p, const struct grep_opt *opt
 	if (!opt->ignore_locale && is_utf8_locale() && !literal)
 		options |= (PCRE2_UTF | PCRE2_UCP | PCRE2_MATCH_INVALID_UTF);
 
+#ifndef GIT_PCRE2_VERSION_10_35_OR_HIGHER
+	/*
+	 * Work around a JIT bug related to invalid Unicode character handling
+	 * fixed in 10.35:
+	 * https://github.com/PCRE2Project/pcre2/commit/c21bd977547d
+	 */
+	options &= ~PCRE2_UCP;
+#endif
+
 #ifndef GIT_PCRE2_VERSION_10_36_OR_HIGHER
 	/* Work around https://bugs.exim.org/show_bug.cgi?id=2642 fixed in 10.36 */
 	if (PCRE2_MATCH_INVALID_UTF && options & (PCRE2_UTF | PCRE2_CASELESS))
diff --git a/grep.h b/grep.h
index 6075f997e68f..c59592e3bdba 100644
--- a/grep.h
+++ b/grep.h
@@ -7,6 +7,9 @@ 
 #if (PCRE2_MAJOR >= 10 && PCRE2_MINOR >= 36) || PCRE2_MAJOR >= 11
 #define GIT_PCRE2_VERSION_10_36_OR_HIGHER
 #endif
+#if (PCRE2_MAJOR >= 10 && PCRE2_MINOR >= 35) || PCRE2_MAJOR >= 11
+#define GIT_PCRE2_VERSION_10_35_OR_HIGHER
+#endif
 #if (PCRE2_MAJOR >= 10 && PCRE2_MINOR >= 34) || PCRE2_MAJOR >= 11
 #define GIT_PCRE2_VERSION_10_34_OR_HIGHER
 #endif