[openssl] OpenSSL_1_1_1-stable update

[Matt Caswell]

The branch OpenSSL_1_1_1-stable has been updated
       via  99f0c7a8a6999e2f78fc065e4da78643ae14c14c (commit)
      from  c352bd07ed2ff872876534c950a6968d75ef121e (commit)


- Log -----------------------------------------------------------------
commit 99f0c7a8a6999e2f78fc065e4da78643ae14c14c
Author: Vitezslav Cizek <vcizek at suse.com>
Date:   Thu Feb 28 13:47:18 2019 +0100

    openssl_strerror_r: Fix handling of GNU strerror_r
    
    GNU strerror_r may return either a pointer to a string that the function
    stores in buf, or a pointer to some (immutable) static string in which case
    buf is unused.
    
    In such a case we need to set buf manually.
    
    Reviewed-by: Bernd Edlinger <bernd.edlinger at hotmail.de>
    Reviewed-by: Matt Caswell <matt at openssl.org>
    (Merged from https://github.com/openssl/openssl/pull/8371)
    
    (cherry picked from commit e3b35d2b29e9446af83fcaa534e67e7b04a60d7a)

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

Summary of changes:
 crypto/o_str.c | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/crypto/o_str.c b/crypto/o_str.c
index a835769..437e45a 100644
--- a/crypto/o_str.c
+++ b/crypto/o_str.c
@@ -223,7 +223,26 @@ int openssl_strerror_r(int errnum, char *buf, size_t buflen)
 #if defined(_MSC_VER) && _MSC_VER>=1400
     return !strerror_s(buf, buflen, errnum);
 #elif defined(_GNU_SOURCE)
-    return strerror_r(errnum, buf, buflen) != NULL;
+    char *err;
+
+    /*
+     * GNU strerror_r may not actually set buf.
+     * It can return a pointer to some (immutable) static string in which case
+     * buf is left unused.
+     */
+    err = strerror_r(errnum, buf, buflen);
+    if (err == NULL)
+        return 0;
+    /*
+     * If err is statically allocated, err != buf and we need to copy the data.
+     * If err points somewhere inside buf, OPENSSL_strlcpy can handle this,
+     * since src and dest are not annotated with __restrict and the function
+     * reads src byte for byte and writes to dest.
+     * If err == buf we do not have to copy anything.
+     */
+    if (err != buf)
+        OPENSSL_strlcpy(buf, err, buflen);
+    return 1;
 #elif (defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 200112L) || \
       (defined(_XOPEN_SOURCE) && _XOPEN_SOURCE >= 600)
     /*
@@ -234,6 +253,7 @@ int openssl_strerror_r(int errnum, char *buf, size_t buflen)
     return !strerror_r(errnum, buf, buflen);
 #else
     char *err;
+
     /* Fall back to non-thread safe strerror()...its all we can do */
     if (buflen < 2)
         return 0;
@@ -241,8 +261,7 @@ int openssl_strerror_r(int errnum, char *buf, size_t buflen)
     /* Can this ever happen? */
     if (err == NULL)
         return 0;
-    strncpy(buf, err, buflen - 1);
-    buf[buflen - 1] = '\0';
+    OPENSSL_strlcpy(buf, err, buflen);
     return 1;
 #endif
 }