[OE-core] [PATCH] libpcre2: fix CVE-2017-7186

Ross Burton ross.burton at intel.com
Wed Mar 6 22:51:01 UTC 2019


Signed-off-by: Ross Burton <ross.burton at intel.com>
---
 .../libpcre/libpcre2/CVE-2017-7186.patch           | 83 ++++++++++++++++++++++
 meta/recipes-support/libpcre/libpcre2_10.32.bb     |  1 +
 2 files changed, 84 insertions(+)
 create mode 100644 meta/recipes-support/libpcre/libpcre2/CVE-2017-7186.patch

diff --git a/meta/recipes-support/libpcre/libpcre2/CVE-2017-7186.patch b/meta/recipes-support/libpcre/libpcre2/CVE-2017-7186.patch
new file mode 100644
index 00000000000..7cd7c27c6c0
--- /dev/null
+++ b/meta/recipes-support/libpcre/libpcre2/CVE-2017-7186.patch
@@ -0,0 +1,83 @@
+libpcre1 in PCRE 8.40 and libpcre2 in PCRE2 10.23 allow remote attackers to
+cause a denial of service (segmentation violation for read access, and
+application crash) by triggering an invalid Unicode property lookup.	
+
+CVE: CVE-2017-7186
+Upstream-Status: Backport
+Signed-off-by: Ross Burton <ross.burton at intel.com>
+
+---
+ src/pcre2_internal.h | 15 ++++++++++++++-
+ src/pcre2_ucd.c      | 14 ++++++++++++++
+ 2 files changed, 28 insertions(+), 1 deletion(-)
+
+diff --git a/src/pcre2_internal.h b/src/pcre2_internal.h
+index 6a8774c..720bbc9 100644
+--- a/src/pcre2_internal.h
++++ b/src/pcre2_internal.h
+@@ -1774,10 +1774,17 @@ typedef struct {
+ /* UCD access macros */
+ 
+ #define UCD_BLOCK_SIZE 128
+-#define GET_UCD(ch) (PRIV(ucd_records) + \
++#define REAL_GET_UCD(ch) (PRIV(ucd_records) + \
+         PRIV(ucd_stage2)[PRIV(ucd_stage1)[(int)(ch) / UCD_BLOCK_SIZE] * \
+         UCD_BLOCK_SIZE + (int)(ch) % UCD_BLOCK_SIZE])
+ 
++#if PCRE2_CODE_UNIT_WIDTH == 32
++#define GET_UCD(ch) ((ch > MAX_UTF_CODE_POINT)? \
++  PRIV(dummy_ucd_record) : REAL_GET_UCD(ch))
++#else
++#define GET_UCD(ch) REAL_GET_UCD(ch)
++#endif
++
+ #define UCD_CHARTYPE(ch)    GET_UCD(ch)->chartype
+ #define UCD_SCRIPT(ch)      GET_UCD(ch)->script
+ #define UCD_CATEGORY(ch)    PRIV(ucp_gentype)[UCD_CHARTYPE(ch)]
+@@ -1834,6 +1841,9 @@ extern const uint8_t          PRIV(utf8_table4)[];
+ #define _pcre2_default_compile_context PCRE2_SUFFIX(_pcre2_default_compile_context_)
+ #define _pcre2_default_match_context   PCRE2_SUFFIX(_pcre2_default_match_context_)
+ #define _pcre2_default_tables          PCRE2_SUFFIX(_pcre2_default_tables_)
++#if PCRE2_CODE_UNIT_WIDTH == 32
++#define _pcre2_dummy_ucd_record        PCRE2_SUFFIX(_pcre2_dummy_ucd_record_)
++#endif
+ #define _pcre2_hspace_list             PCRE2_SUFFIX(_pcre2_hspace_list_)
+ #define _pcre2_vspace_list             PCRE2_SUFFIX(_pcre2_vspace_list_)
+ #define _pcre2_ucd_caseless_sets       PCRE2_SUFFIX(_pcre2_ucd_caseless_sets_)
+@@ -1858,6 +1868,9 @@ extern const uint32_t                  PRIV(hspace_list)[];
+ extern const uint32_t                  PRIV(vspace_list)[];
+ extern const uint32_t                  PRIV(ucd_caseless_sets)[];
+ extern const ucd_record                PRIV(ucd_records)[];
++#if PCRE2_CODE_UNIT_WIDTH == 32
++extern const ucd_record                PRIV(dummy_ucd_record)[];
++#endif
+ extern const uint8_t                   PRIV(ucd_stage1)[];
+ extern const uint16_t                  PRIV(ucd_stage2)[];
+ extern const uint32_t                  PRIV(ucp_gbtable)[];
+diff --git a/src/pcre2_ucd.c b/src/pcre2_ucd.c
+index 116f537..56aa29d 100644
+--- a/src/pcre2_ucd.c
++++ b/src/pcre2_ucd.c
+@@ -41,6 +41,20 @@ const uint32_t PRIV(ucd_caseless_sets)[] = {0};
+ 
+ const char *PRIV(unicode_version) = "8.0.0";
+ 
++/* If the 32-bit library is run in non-32-bit mode, character values
++greater than 0x10ffff may be encountered. For these we set up a
++special record. */
++
++#if PCRE2_CODE_UNIT_WIDTH == 32
++const ucd_record PRIV(dummy_ucd_record)[] = {{
++  ucp_Common,    /* script */
++  ucp_Cn,        /* type unassigned */
++  ucp_gbOther,   /* grapheme break property */
++  0,             /* case set */
++  0,             /* other case */
++  }};
++#endif
++
+ /* When recompiling tables with a new Unicode version, please check the
+ types in this structure definition from pcre2_internal.h (the actual
+ field names will be different):
+-- 
+2.12.1
diff --git a/meta/recipes-support/libpcre/libpcre2_10.32.bb b/meta/recipes-support/libpcre/libpcre2_10.32.bb
index 3a0aa53029f..59953626c74 100644
--- a/meta/recipes-support/libpcre/libpcre2_10.32.bb
+++ b/meta/recipes-support/libpcre/libpcre2_10.32.bb
@@ -12,6 +12,7 @@ LIC_FILES_CHKSUM = "file://LICENCE;md5=cf66d307bf03bae65d413eb7a8e603a0"
 
 SRC_URI = "https://ftp.pcre.org/pub/pcre/pcre2-${PV}.tar.bz2 \
            file://pcre-cross.patch \
+           file://CVE-2017-7186.patch \
 "
 
 SRC_URI[md5sum] = "8a096287153fb994970df3570e90fcb5"
-- 
2.11.0



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