From fb1e4a18589dcd6dcf8bab488503e3ce89873098 Mon Sep 17 00:00:00 2001 From: dgp Date: Thu, 21 Apr 2011 16:53:44 +0000 Subject: Limits on list length were too strict. Revised panics to errors where possible. --- ChangeLog | 4 ++ generic/tclCmdIL.c | 17 +++---- generic/tclInt.h | 3 ++ generic/tclListObj.c | 125 +++++++++++++++++++++++++++++++++------------------ 4 files changed, 93 insertions(+), 56 deletions(-) diff --git a/ChangeLog b/ChangeLog index bce5d58..e593b99 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,9 @@ 2011-04-21 Don Porter + * generic/tclCmdIL.c: Limits on list length were too strict. + * generic/tclInt.h: Revised panics to errors where possible. + * generic/tclListObj.c: + * generic/tclCompile.c: Make sure SetFooFromAny routines react * generic/tclIO.c: reasonably when passed a NULL interp. * generic/tclIndexObj.c: diff --git a/generic/tclCmdIL.c b/generic/tclCmdIL.c index 25fd078..13db6d5 100644 --- a/generic/tclCmdIL.c +++ b/generic/tclCmdIL.c @@ -2429,21 +2429,14 @@ Tcl_LrepeatObjCmd( objc -= 2; objv += 2; - /* - * Final sanity check. Total number of elements must fit in a signed - * integer. We also limit the number of elements to 512M-1 so allocations - * on 32-bit machines are guaranteed to be less than 2GB! [Bug 2130992] - */ + /* Final sanity check. Do not exceed limits on max list length. */ - totalElems = objc * elementCount; - if (totalElems/objc != elementCount || totalElems/elementCount != objc) { - Tcl_AppendResult(interp, "too many elements in result list", NULL); - return TCL_ERROR; - } - if (totalElems >= 0x20000000) { - Tcl_AppendResult(interp, "too many elements in result list", NULL); + if (objc > LIST_MAX/elementCount) { + Tcl_SetObjResult(interp, Tcl_ObjPrintf( + "max length of a Tcl list (%d elements) exceeded", LIST_MAX)); return TCL_ERROR; } + totalElems = objc * elementCount; /* * Get an empty list object that is allocated large enough to hold each diff --git a/generic/tclInt.h b/generic/tclInt.h index ca565dd..e410a1d 100644 --- a/generic/tclInt.h +++ b/generic/tclInt.h @@ -2193,6 +2193,9 @@ typedef struct List { * accomodate all elements. */ } List; +#define LIST_MAX \ + (1 + (int)(((size_t)UINT_MAX - sizeof(List))/sizeof(Tcl_Obj *))) + /* * Macro used to get the elements of a list object. */ diff --git a/generic/tclListObj.c b/generic/tclListObj.c index 751cc13..730b94d 100644 --- a/generic/tclListObj.c +++ b/generic/tclListObj.c @@ -17,7 +17,9 @@ * Prototypes for functions defined later in this file: */ -static List * NewListIntRep(int objc, Tcl_Obj *CONST objv[]); +static List * AttemptNewList(Tcl_Interp *interp, int objc, + Tcl_Obj *CONST objv[]); +static List * NewListIntRep(int objc, Tcl_Obj *CONST objv[], int p); static void DupListInternalRep(Tcl_Obj *srcPtr, Tcl_Obj *copyPtr); static void FreeListInternalRep(Tcl_Obj *listPtr); static int SetListFromAny(Tcl_Interp *interp, Tcl_Obj *objPtr); @@ -49,16 +51,16 @@ Tcl_ObjType tclListType = { * * NewListIntRep -- * - * If objc>0 and objv!=NULL, this function creates a list internal rep - * with objc elements given in the array objv. If objc>0 and objv==NULL - * it creates the list internal rep of a list with 0 elements, where - * enough space has been preallocated to store objc elements. If objc<=0, - * it returns NULL. + * Creates a list internal rep with space for objc elements. objc + * must be > 0. If objv!=NULL, initializes with the first objc values + * in that array. If objv==NULL, initalize list internal rep to have + * 0 elements, with space to add objc more. Flag value "p" indicates + * how to behave on failure. * * Results: - * A new List struct is returned. If objc<=0 or if the allocation fails - * for lack of memory, NULL is returned. The list returned has refCount - * 0. + * A new List struct with refCount 0 is returned. If some failure + * prevents this then if p=0, NULL is returned and otherwise the + * routine panics. * * Side effects: * The ref counts of the elements in objv are incremented since the @@ -70,12 +72,13 @@ Tcl_ObjType tclListType = { static List * NewListIntRep( int objc, - Tcl_Obj *CONST objv[]) + Tcl_Obj *CONST objv[], + int p) { List *listRepPtr; if (objc <= 0) { - return NULL; + Tcl_Panic("NewListIntRep: expects postive element count"); } /* @@ -85,13 +88,21 @@ NewListIntRep( * requires API changes to fix. See [Bug 219196] for a discussion. */ - if ((size_t)objc > INT_MAX/sizeof(Tcl_Obj *)) { + if ((size_t)objc > LIST_MAX) { + if (p) { + Tcl_Panic("max length of a Tcl list (%d elements) exceeded", + LIST_MAX); + } return NULL; } listRepPtr = (List *) attemptckalloc(sizeof(List) + ((objc-1) * sizeof(Tcl_Obj *))); if (listRepPtr == NULL) { + if (p) { + Tcl_Panic("list creation failed: unable to alloc %u bytes", + sizeof(List) + ((objc-1) * sizeof(Tcl_Obj *))); + } return NULL; } @@ -118,6 +129,50 @@ NewListIntRep( /* *---------------------------------------------------------------------- * + * AttemptNewList -- + * + * Creates a list internal rep with space for objc elements. objc + * must be > 0. If objv!=NULL, initializes with the first objc values + * in that array. If objv==NULL, initalize list internal rep to have + * 0 elements, with space to add objc more. + * + * Results: + * A new List struct with refCount 0 is returned. If some failure + * prevents this then NULL is returned, and an error message is left + * in the interp result, unless interp is NULL. + * + * Side effects: + * The ref counts of the elements in objv are incremented since the + * resulting list now refers to them. + * + *---------------------------------------------------------------------- + */ + +static List * +AttemptNewList( + Tcl_Interp *interp, + int objc, + Tcl_Obj *CONST objv[]) +{ + List *listRepPtr = NewListIntRep(objc, objv, 0); + + if (interp != NULL && listRepPtr == NULL) { + if (objc > LIST_MAX) { + Tcl_SetObjResult(interp, Tcl_ObjPrintf( + "max length of a Tcl list (%d elements) exceeded", + LIST_MAX)); + } else { + Tcl_SetObjResult(interp, Tcl_ObjPrintf( + "list creation failed: unable to alloc %u bytes", + sizeof(List) + ((objc-1) * sizeof(Tcl_Obj *)))); + } + } + return listRepPtr; +} + +/* + *---------------------------------------------------------------------- + * * Tcl_NewListObj -- * * This function is normally called when not debugging: i.e., when @@ -172,10 +227,7 @@ Tcl_NewListObj( * Create the internal rep. */ - listRepPtr = NewListIntRep(objc, objv); - if (!listRepPtr) { - Tcl_Panic("Not enough memory to allocate list"); - } + listRepPtr = NewListIntRep(objc, objv, 1); /* * Now create the object. @@ -244,10 +296,7 @@ Tcl_DbNewListObj( * Create the internal rep. */ - listRepPtr = NewListIntRep(objc, objv); - if (!listRepPtr) { - Tcl_Panic("Not enough memory to allocate list"); - } + listRepPtr = NewListIntRep(objc, objv, 1); /* * Now create the object. @@ -326,10 +375,7 @@ Tcl_SetListObj( */ if (objc > 0) { - listRepPtr = NewListIntRep(objc, objv); - if (!listRepPtr) { - Tcl_Panic("Cannot allocate enough memory for Tcl_SetListObj"); - } + listRepPtr = NewListIntRep(objc, objv, 1); objPtr->internalRep.twoPtrValue.ptr1 = (void *) listRepPtr; objPtr->internalRep.twoPtrValue.ptr2 = NULL; objPtr->typePtr = &tclListType; @@ -587,9 +633,9 @@ Tcl_ListObjAppendElement( List *oldListRepPtr = listRepPtr; Tcl_Obj **oldElems; - listRepPtr = NewListIntRep(newMax, NULL); - if (!listRepPtr) { - Tcl_Panic("Not enough memory to allocate list"); + listRepPtr = AttemptNewList(interp, newMax, NULL); + if (listRepPtr == NULL) { + return TCL_ERROR; } oldElems = &oldListRepPtr->elements; elemPtrs = &listRepPtr->elements; @@ -884,9 +930,9 @@ Tcl_ListObjReplace( newMax = listRepPtr->maxElemCount; } - listRepPtr = NewListIntRep(newMax, NULL); - if (!listRepPtr) { - Tcl_Panic("Not enough memory to allocate list"); + listRepPtr = AttemptNewList(interp, newMax, NULL); + if (listRepPtr == NULL) { + return TCL_ERROR; } listPtr->internalRep.twoPtrValue.ptr1 = (void *) listRepPtr; @@ -1527,9 +1573,9 @@ TclListObjSetElement( Tcl_Obj **oldElemPtrs = elemPtrs; int i; - listRepPtr = NewListIntRep(listRepPtr->maxElemCount, NULL); + listRepPtr = AttemptNewList(interp, listRepPtr->maxElemCount, NULL); if (listRepPtr == NULL) { - Tcl_Panic("Not enough memory to allocate list"); + return TCL_ERROR; } listRepPtr->canonicalFlag = oldListRepPtr->canonicalFlag; elemPtrs = &listRepPtr->elements; @@ -1691,13 +1737,8 @@ SetListFromAny( */ Tcl_DictObjSize(NULL, objPtr, &size); - listRepPtr = NewListIntRep(size > 0 ? 2*size : 1, NULL); + listRepPtr = AttemptNewList(interp, size > 0 ? 2*size : 1, NULL); if (!listRepPtr) { - if (interp) { - Tcl_SetResult(interp, - "insufficient memory to allocate list working space", - TCL_STATIC); - } return TCL_ERROR; } listRepPtr->elemCount = 2 * size; @@ -1753,12 +1794,8 @@ SetListFromAny( * strings. */ - listRepPtr = NewListIntRep(estCount, NULL); - if (!listRepPtr) { - if (interp) { - Tcl_SetObjResult(interp, Tcl_NewStringObj( - "Not enough memory to allocate the list internal rep", -1)); - } + listRepPtr = AttemptNewList(interp, estCount, NULL); + if (listRepPtr == NULL) { return TCL_ERROR; } elemPtrs = &listRepPtr->elements; -- cgit v0.12