The branch master has been updated
       via  767db672c429aeb98a68b0e310dea15f1b48eb84 (commit)
      from  7e35458b511f042d9a37d49227b01096c444e575 (commit)


- Log -----------------------------------------------------------------
commit 767db672c429aeb98a68b0e310dea15f1b48eb84
Author: Tomas Mraz <[email protected]>
Date:   Wed Oct 13 09:00:31 2021 +0200

    cmp.c: Avoid dereference with negative index and use memcpy
    
    This prevents a compile-time warning on newer gcc.
    
    Also fix the related warning message.
    
    Fixes #16814
    
    Reviewed-by: Shane Lontis <[email protected]>
    Reviewed-by: Paul Dale <[email protected]>
    (Merged from https://github.com/openssl/openssl/pull/16821)

-----------------------------------------------------------------------

Summary of changes:
 apps/cmp.c | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/apps/cmp.c b/apps/cmp.c
index 170ac816f2..b6e88e64f6 100644
--- a/apps/cmp.c
+++ b/apps/cmp.c
@@ -1989,7 +1989,7 @@ static void print_itavs(STACK_OF(OSSL_CMP_ITAV) *itavs)
 }
 
 static char opt_item[SECTION_NAME_MAX + 1];
-/* get previous name from a comma-separated list of names */
+/* get previous name from a comma or space-separated list of names */
 static const char *prev_item(const char *opt, const char *end)
 {
     const char *beg;
@@ -1998,19 +1998,28 @@ static const char *prev_item(const char *opt, const 
char *end)
     if (end == opt)
         return NULL;
     beg = end;
-    while (beg != opt && beg[-1] != ',' && !isspace(beg[-1]))
-        beg--;
+    while (beg > opt) {
+        --beg;
+        if (beg[0] == ',' || isspace(beg[0])) {
+            ++beg;
+            break;
+        }
+    }
     len = end - beg;
     if (len > SECTION_NAME_MAX) {
-        CMP_warn2("using only first %d characters of section name starting 
with \"%s\"",
-                  SECTION_NAME_MAX, opt_item);
+        CMP_warn3("using only first %d characters of section name starting 
with \"%.*s\"",
+                  SECTION_NAME_MAX, SECTION_NAME_MAX, beg);
         len = SECTION_NAME_MAX;
     }
-    strncpy(opt_item, beg, len);
-    opt_item[SECTION_NAME_MAX] = '\0'; /* avoid gcc v8 O3 stringop-truncation 
*/
+    memcpy(opt_item, beg, len);
     opt_item[len] = '\0';
-    while (beg != opt && (beg[-1] == ',' || isspace(beg[-1])))
-        beg--;
+    while (beg > opt) {
+        --beg;
+        if (beg[0] != ',' && !isspace(beg[0])) {
+            ++beg;
+            break;
+        }
+    }
     return beg;
 }
 

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