diff options
| -rw-r--r-- | ChangeLog | 6 | ||||
| -rw-r--r-- | generic/tclStringObj.c | 33 |
2 files changed, 35 insertions, 4 deletions
@@ -1,3 +1,9 @@ +2009-02-05 Don Porter <dgp@users.sourceforge.net> + + * generic/tclStringObj.c: Added overflow protections to the + AppendUtfToUtfRep routine to either avoid invalid arguments and + crashes, or to replace them with controlled panics. [Bug 2561794] + 2009-02-04 Don Porter <dgp@users.sourceforge.net> * generic/tclStringObj.c (SetUnicodeObj): Corrected failure of diff --git a/generic/tclStringObj.c b/generic/tclStringObj.c index 2325d1f..8d5bb6f 100644 --- a/generic/tclStringObj.c +++ b/generic/tclStringObj.c @@ -33,7 +33,7 @@ * See the file "license.terms" for information on usage and redistribution * of this file, and for a DISCLAIMER OF ALL WARRANTIES. * - * RCS: @(#) $Id: tclStringObj.c,v 1.32.2.5 2009/02/04 22:39:47 dgp Exp $ */ + * RCS: @(#) $Id: tclStringObj.c,v 1.32.2.6 2009/02/05 14:10:58 dgp Exp $ */ #include "tclInt.h" @@ -743,6 +743,14 @@ Tcl_SetObjLength(objPtr, length) { String *stringPtr; + if (length < 0) { + /* + * Setting to a negative length is nonsense. This is probably the + * result of overflowing the signed integer range. + */ + Tcl_Panic("Tcl_SetObjLength: negative length requested: " + "%d (integer overflow?)", length); + } if (Tcl_IsShared(objPtr)) { panic("Tcl_SetObjLength called with shared object"); } @@ -752,7 +760,7 @@ Tcl_SetObjLength(objPtr, length) /* Check that we're not extending a pure unicode string */ - if (length > (int) stringPtr->allocated && + if ((size_t)length > stringPtr->allocated && (objPtr->bytes != NULL || stringPtr->hasUnicode == 0)) { char *new; @@ -838,6 +846,13 @@ Tcl_AttemptSetObjLength(objPtr, length) { String *stringPtr; + if (length < 0) { + /* + * Setting to a negative length is nonsense. This is probably the + * result of overflowing the signed integer range. + */ + return 0; + } if (Tcl_IsShared(objPtr)) { panic("Tcl_AttemptSetObjLength called with shared object"); } @@ -1377,6 +1392,9 @@ AppendUtfToUtfRep(objPtr, bytes, numBytes) */ oldLength = objPtr->length; + if (numBytes > INT_MAX - oldLength) { + Tcl_Panic("max size for a Tcl value (%d bytes) exceeded", INT_MAX); + } newLength = numBytes + oldLength; stringPtr = GET_STRING(objPtr); @@ -1391,8 +1409,15 @@ AppendUtfToUtfRep(objPtr, bytes, numBytes) */ if (Tcl_AttemptSetObjLength(objPtr, 2 * newLength) == 0) { - Tcl_SetObjLength(objPtr, - newLength + numBytes + TCL_GROWTH_MIN_ALLOC); + /* + * Take care computing the amount of modest growth to avoid + * overflow into invalid argument values for Tcl_SetObjLength. + */ + unsigned int limit = INT_MAX - newLength; + unsigned int extra = numBytes + TCL_GROWTH_MIN_ALLOC; + int growth = (int) ((extra > limit) ? limit : extra); + + Tcl_SetObjLength(objPtr, newLength + growth); } } |