Avoid a potential (harmless) signed integer overflow in memory usage

accounting when calling sqlite3_realloc() to reduce the size of an
allocation.

FossilOrigin-Name: 2d71cbdf6bc24f0269027c70b39ea7f342436bdb

diff --git a/manifest b/manifest
index a1a4c4b69eb70eb28a36666e773e50a7f786d3da..5efd5be1042a8021e6da3e35a50e5f5ef5a8d85a 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Minor\schanges\sto\smake\ssome\snewer\stest\scases\swork\sunder\smore\scompile-time\noptions.
-D 2016-12-27T02:43:47.038
+C Avoid\sa\spotential\s(harmless)\ssigned\sinteger\soverflow\sin\smemory\susage\naccounting\swhen\scalling\ssqlite3_realloc()\sto\sreduce\sthe\ssize\sof\san\nallocation.
+D 2016-12-27T12:08:36.304
 F Makefile.in 41bd4cad981487345c4a84081074bcdb876e4b2e
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc b8ca53350ae545e3562403d5da2a69cec79308da
@@ -354,7 +354,7 @@ F src/insert.c 91ba5d0143e66479081536ebbaff1850ec9f57d9
 F src/legacy.c 75d3023be8f0d2b99d60f905090341a03358c58e
 F src/loadext.c 5d6642d141c07d366e43d359e94ec9de47add41d
 F src/main.c ec789a410860bcdc5d8f7a82090043f482482aec
-F src/malloc.c 5ee7c2d3dcb1b0a902c9c6d0115deef54736bdfa
+F src/malloc.c f3fad34cd570022abca558c573f1761fb09a8212
 F src/mem0.c 6a55ebe57c46ca1a7d98da93aaa07f99f1059645
 F src/mem1.c 6919bcf12f221868ea066eec27e579fed95ce98b
 F src/mem2.c f1940d9e91948dd6a908fbb9ce3835c36b5d83c3
@@ -1539,7 +1539,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P edc9db41f3ee200ba44579a46ed8331bbbbf539e
-R 96afac5b20dcc0117476250a7301f42d
+P 382eea36c56f866efee1321f643687a4061e8b9e
+R 93ac45881220ef048be2df84ae58f915
 U drh
-Z 51bc03a9fcd5bae5965694035444d10d
+Z 198951405d8d4aa948aae7ef07798be3

diff --git a/manifest.uuid b/manifest.uuid
index 9b729c87bb5b9fce22936e087f39b141490ac5a0..28b15c57b0f687290e21e995001124240761d234 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-382eea36c56f866efee1321f643687a4061e8b9e
\ No newline at end of file
+2d71cbdf6bc24f0269027c70b39ea7f342436bdb
\ No newline at end of file

diff --git a/src/malloc.c b/src/malloc.c
index 4ec1bca57cad9c866c8ac4582cdd5bd5f659b65b..84191c78a10915fbd0eb3ddf47a06c766633ffbd 100644 (file)
--- a/src/malloc.c
+++ b/src/malloc.c
@@ -519,7 +519,7 @@ void *sqlite3Realloc(void *pOld, u64 nBytes){
     sqlite3_mutex_enter(mem0.mutex);
     sqlite3StatusHighwater(SQLITE_STATUS_MALLOC_SIZE, (int)nBytes);
     nDiff = nNew - nOld;
-    if( sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED) >= 
+    if( nDiff>0 && sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED) >= 
           mem0.alarmThreshold-nDiff ){
       sqlite3MallocAlarm(nDiff);
     }