Commit Diff

Commit:
7348a3998ad2435a907529cc66d605a9e890ea31
From:
Sergey Bronnikov <sergeyb@tarantool.org>
Via:
Sergey Kaplun <sergey_v_kaplun@mail.ru>
Date:
Message:
varbinary: fix UB in a varbinary.new() With enabled UndefinedBehavior Sanitizer runtime error like below is triggered: NO_WRAP $ UBSAN_OPTIONS=external_symbolizer_path=/usr/lib/llvm-13/bin/llvm-symbolizer:print_stacktrace=1 $ ./build/src/tarantool -e "require('varbinary').new()" /home/sergeyb/sources/MRG/tarantool/third_party/luajit/src/lib_ffi.c:710:14: \ runtime error: null pointer passed as argument 2, which is declared to never be null /usr/include/string.h:44:28: note: nonnull attribute specified here NO_WRAP This happened because in the varbinary constructor, the NULL pointer was passed to `ffi.copy()` and then to `memcpy()`, which is an undefined behaviour. The patch fixes that. Needed for #10145 NO_CHANGELOG=codehealth NO_DOC=codehealth NO_TEST=codehealth (cherry picked from commit 30179d44da65f835d81494ad63e86935f1c5aad0)
Actions:
Patch | Tree
commit - f2d64a14b0292001579bb6e9af2544f67d573d4b
commit + 7348a3998ad2435a907529cc66d605a9e890ea31
blob - fa32cb71c37fb25be60e922be98c267f4f316b9c
blob + 6f1c1d952a0647a585e2a528317348ea2c2e72e8
--- src/lua/varbinary.lua
+++ src/lua/varbinary.lua
@@ -24,7 +24,9 @@ local function new_varbinary(data, size)
         error('Usage: varbinary.new(str) or varbinary.new(ptr, size)', 2)
     end
     local bin = ffi.new(varbinary_t, size)
-    ffi.copy(bin, data, size)
+    if size ~= 0 then
+        ffi.copy(bin, data, size)
+    end
     return bin
 end