[Libreoffice-commits] online.git: common/Session.cpp

[Miklos Vajna (via logerrit)]

 common/Session.cpp |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

New commits:
commit 204cff5c192eeb60205c6c33914ed506c529780a
Author:     Miklos Vajna <vmiklos at collabora.com>
AuthorDate: Fri Nov 22 14:11:00 2019 +0100
Commit:     Miklos Vajna <vmiklos at collabora.com>
CommitDate: Fri Nov 22 14:11:00 2019 +0100

    Avoid UB in Session::setHash()
    
    Ubsan says that signed integer overflow is happening here:
    
        #0 0xec344a in Session::setHash(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) common/Session.cpp:267:17
        #1 0x918b54 in DocumentBroker::load(std::shared_ptr<ClientSession> const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) wsd/DocumentBroker.cpp:682:18
    ...
    SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior common/Session.cpp:267:17 in
    
    (While running unit_wopi_watermark.)
    
    Change-Id: Idcb1692f6d5d0df8be35dc557d2d72a345acbcf4

diff --git a/common/Session.cpp b/common/Session.cpp
index 9495cc99a..1e4c76573 100644
--- a/common/Session.cpp
+++ b/common/Session.cpp
@@ -257,8 +257,8 @@ void Session::getIOStats(uint64_t &sent, uint64_t &recv)
 
 void Session::setHash(const std::string& text)
  {
-    int hash = 0x811C9DC5;
-    int prime = 0x1000193;
+    unsigned int hash = 0x811C9DC5;
+    unsigned int prime = 0x1000193;
 
     if (!text.empty())
     {
@@ -268,7 +268,7 @@ void Session::setHash(const std::string& text)
            hash *= prime;
        }
     }
-    _hash = abs(hash);
+    _hash = abs(static_cast<int>(hash));
  }