Make sure the size parameter to read and write VFS methods in the unix VFS

do not become too big or go negative.  This was not actually possible in the
current code.  The checks are added to make sure some future bug does not
make it possible.

FossilOrigin-Name: daebe3bd2d9bd7b6f876a8110cf5045eb3fee078

diff --git a/manifest b/manifest
index 07b54cc849f6b04a6ccd3c3e078df5d031b30e1d..0bf6940ec3a7363e42821402feee4c2b8fff5a2b 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Ensure\sthat\sthe\svalue\sreturned\sby\sxSectorSize()\sis\sreasonable\s(currently\sdefined\sas\sbetween\s2^5\sand\s2^16\sbytes)\sbefore\susing\sit\sto\scalculate\sthe\samount\sof\spadding\sto\sadd\sto\sa\swal\sfile.
-D 2012-10-01T06:50:55.576
+C Make\ssure\sthe\ssize\sparameter\sto\sread\sand\swrite\sVFS\smethods\sin\sthe\sunix\sVFS\ndo\snot\sbecome\stoo\sbig\sor\sgo\snegative.\s\sThis\swas\snot\sactually\spossible\sin\sthe\ncurrent\scode.\s\sThe\schecks\sare\sadded\sto\smake\ssure\ssome\sfuture\sbug\sdoes\snot\nmake\sit\spossible.
+D 2012-10-01T12:16:26.771
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 5f4f26109f9d80829122e0e09f9cda008fa065fb
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -160,7 +160,7 @@ F src/notify.c 976dd0f6171d4588e89e874fcc765e92914b6d30
 F src/os.c e1acdc09ff3ac2412945cca9766e2dcf4675f31c
 F src/os.h 027491c77d2404c0a678bb3fb06286f331eb9b57
 F src/os_common.h 92815ed65f805560b66166e3583470ff94478f04
-F src/os_unix.c 69b2fe66316524eebf5f1ce85c1fdfe2952307e9
+F src/os_unix.c a5a45a2857c43b37bac145b521064a85a544cd7a
 F src/os_win.c 90c7a1fe2698867555ba4266f5bd436c85d0d1dc
 F src/pager.c 9f5f2823594cc2848e151510f726af02896485b5
 F src/pager.h bdbc379557eb2e233dfec10986b3086877e72db7
@@ -1018,7 +1018,7 @@ F tool/vdbe-compress.tcl f12c884766bd14277f4fcedcae07078011717381
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh fbc018d67fd7395f440c28f33ef0f94420226381
 F tool/win/sqlite.vsix 67d8a99aceb56384a81b3f30d6c71743146d2cc9
-P 62225b4a4c4bfe1820ef54cb202edf2cd866429f
-R 09d3e5b05c9dfd1b20715f593e6818b6
-U dan
-Z 07828d460d32254f1342208677faf52f
+P 6b4ff83bff07d427af585c9fd03be90abf2fc82f
+R 43398c1dd9f4f691234256568baab7a2
+U drh
+Z 321bb2af8cac9de7aef8d0d7efaf3889

diff --git a/manifest.uuid b/manifest.uuid
index 19bd1d6a9722d75b1bb3e8b595c088cbba6c7d1e..1db2bb2963c8a20e50b9a0e9c1453bcabe4d2811 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-6b4ff83bff07d427af585c9fd03be90abf2fc82f
\ No newline at end of file
+daebe3bd2d9bd7b6f876a8110cf5045eb3fee078
\ No newline at end of file

diff --git a/src/os_unix.c b/src/os_unix.c
index c0df66e8e07ecca54783d70a85011cf33546dd24..0852eb1a891f620aae1f998b06efb9a30b8e2d91 100644 (file)
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -3010,6 +3010,8 @@ static int seekAndRead(unixFile *id, sqlite3_int64 offset, void *pBuf, int cnt){
   i64 newOffset;
 #endif
   TIMER_START;
+  assert( cnt==(cnt&0x1ffff) );
+  cnt &= 0x1ffff;
   do{
 #if defined(USE_PREAD)
     got = osPread(id->h, pBuf, cnt, offset);
@@ -3099,6 +3101,8 @@ static int seekAndWrite(unixFile *id, i64 offset, const void *pBuf, int cnt){
 #if (!defined(USE_PREAD) && !defined(USE_PREAD64))
   i64 newOffset;
 #endif
+  assert( cnt==(cnt&0x1ffff) );
+  cnt &= 0x1ffff;
   TIMER_START;
 #if defined(USE_PREAD)
   do{ got = osPwrite(id->h, pBuf, cnt, offset); }while( got<0 && errno==EINTR );